Go hug a tree. You just might live longer.

edgewater willow tree
edgewater willow tree

The iconic willow tree at Edgewater Park (courtesy of Francis Angelone).

Once upon a time, Cleveland was the Forest City. When Moses Cleaveland arrived to survey Connecticut’s Western Reserve in 1796, the area was heavily forested. It was said that a squirrel could travel from the Atlantic Ocean to the Mississippi River without ever touching the ground.

These days, only the moniker remains. We still have Forest City Enterprises, Forest City Brewery, Forest City Portage, etc. The trees? Not so much.

According to Cuyahoga County’s Urban Tree Canopy Assessment, just 19.2% of the city remains forested. Nearly all of the trees that existed during Cleaveland’s trip to the city that (largely) bears his name are gone today. In 1946, city officials identified 150 trees that likely existed in 1796. When the city updated this inventory in 1975, just 92 remained; of these, only 15 still had the plaques that were installed in 1946.

cuyahoga county tree canopy by community

The existing tree canopy, by community, in Cuyahoga County (courtesy of Cuyahoga County Planning Commission).

Only two of Cuyahoga County’s 59 communities have less tree cover than Cleveland, and the city lags behind comparable cities, including Cincinnati (38%) and Pittsburgh (40%). According to projections, unless Cleveland reverses this trend, its tree canopy will fall to just 14% by 2040. This would represent a loss of 97 acres of urban forest annually over the next 25 years.

When you consider some of Cleveland’s pressing challenges – a 56% child poverty rate, violent crime, population loss – the number of trees within city limits may not seem like a big deal. But we cannot consider the city’s environmental challenges as distinct from its general urban challenges; they are intrinsically connected. Our tremendous urban struggles exacerbate our environmental issues, including tree cover, and these environmental issues subsequently compound these broader issues.

Cleveland’s trees are terrific

When I think about trees, my mind immediately goes to that strangely catchy 1970s commercial from the National Arbor Day Foundation:

And it’s true, trees are terrific. In fact, they’re freaking incredible. But, as the singing cardinal in that commercial indicates, sometimes we take for granted the best things ever planted.

For many Clevelanders, trees may seem like more of a hassle than they’re worth. They produce tons of leaves, fruit, and sap that coats lawns and clogs gutters. They can damage sidewalks. Their roots may get into water and sewer pipes. They may fall in a storm and damage your property or that of a neighbor.

But the costs of trees only outweigh their benefits when we fail to account properly for the latter. Fortunately, the City of Cleveland and a number of partner organizations have placed  a price tag on the myriad benefits that our trees provide in The Cleveland Tree Plan (PDF), which was released last October.

Utilizing the U.S. Forest Service’s i-Tree model, the document estimates that the city’s trees provide more than $28 million in ecosystem services each year. Cleveland’s trees intercept 1.8 billion gallons of rainwater, which helps to mitigate our ongoing challenges with flash flooding. The trees shade homes, lowering energy costs by $3.5 million each year, as well as increase property values by $4.5 million. They also play an important role in mitigating climate change, as they remove 42,000 tons of carbon dioxide per year.

In the plan’s appendices (PDF), which you have to be a massive nerd like me to read, the Tree Plan actually lays out these ecosystem services by neighborhood. As the table below shows, there is a clear overlap between the extent of a neighborhood’s tree canopy and a host of other issues, including energy costs, asthma rates, and property values. The correlation between a neighborhood’s tree canopy and its urban heat island risk, for instance, is extremely strong (0.7609) and statistically significant (p < 0.0001).

cleveland tree benefits by neighborhood

The tree canopy and related statistics in each of Cleveland’s neighborhoods (courtesy of City of Cleveland).

Trees and mortality rates

On its surface, all of this makes sense. It’s fairly obviously that trees filter out air pollution, mitigate stormwater runoff, store carbon, beautify neighborhoods, and shade homes. But trees can do so much more, including extend your lifespan.

A recent study in the journal Environmental Health Perspectives examines the relationship between “greenness,” a measure of vegetation cover (including trees) and mortality rates among a cohort of female nurses in the U.S. The researchers, led by up Dr. Peter James from the Harvard School of Public Health, utilized satellite images to measure the amount of vegetation within 250 and 1,250 meters of each woman’s residence. The 250-meter diameter represented the vegetation directly accessible from each woman’s home, while the 1,250-meter buffer accounted for vegetation within a 10- to 15-minute walk.

The authors considered four main pathways through which exposure to vegetation can affect mortality rates: physical activity, air pollution, social engagement, and mental health. They also controlled for a range of potentially confounding factors, including race/ethnicity, smoking status, socioeconomic status, region, and whether the person lived in a urban area.

According to James et al., higher levels of “greenness” significantly lowered mortality rates among the women in the study cohort.

Analyses showed a consistent relationship between higher greenness and decreased mortality that was robust to adjustment for individual- and area-level covariates. In fully adjusted models, those living in the highest quintile of cumulative average greenness in the 250m area around their home had a 12% lower rate of mortality compared to those in the lowest quintile. Results were consistent for the 1,250m radius, although the relationship was slightly attenuated.

Greater exposure to vegetation significantly reduced mortality rates from cancer, respiratory disease, and kidney disease by 13%, 35%, and 41%, respectively. Of the four pathways studied, the effects were greatest for mental health and social engagement, though “greenness” also reduced mortality related to fine particulate matter and a lack of physical activity.

Based on their research, James et al. conclude,

[T]hese findings suggest that green vegetation has a protective effect, and that policies to increase vegetation in both urban and rural areas may provide opportunities for physical activity, reduce harmful exposures, increase social engagement, and improve mental health. While the recognized benefits of planting vegetation include reducing wastewater loads, sequestering carbon, and mitigating the effects of climate change, evidence of an association between vegetation and lower mortality rates suggests a potential co-benefit to improve health, presenting planners, landscape architects, and policy-makers with an actionable tool to grow healthier places.

Clearly, city officials should work to expand urban tree canopies in order to mitigate the myriad social, environmental, and health issues that plague cities like Cleveland. Fortunately, Cleveland has taken the first step on this road with the release and adoption of its tree plan. Hopefully we can work together to expand the city’s tree canopy in order to tap into the numerous benefits that trees provide.

Maybe the next time you look out your window at your tree lawn, you will see the tree standing there in a different light. It’s time we appreciate and better care for our trees in Cleveland. They just might extend your life.

Actually, fuel economy standards are a great way to tackle carbon emissions

plug-in hybrid prius
plug-in hybrid prius

A Toyota Prius plug-in hybrid vehicle (courtesy of Wikimedia Commons).

It feels like it’s been ages since I wrote a post taking down something that someone else has written. I get the impression that is what people enjoy on the World Wide Web these days, plus it’s pretty fun to rip apart a person’s specious argument – using peer-reviewed literature and well-sourced facts, of course.

With that in mind, I feel somewhat obligated to address an op-ed I read in the Los Angeles Times on Monday from Salim Furth, a research fellow at the conservative think tank The Heritage Foundation. In the piece, Furth argues that state and federal fuel economy standards are a poor policy tool for limiting mobile greenhouse gas (GHG) emissions and that they unfairly harm low-income families. Instead, he calls for California state officials to focus their attention on land use reforms that would “allow denser, environmentally conscious construction” to “make residents less dependent on car.”

On the surface, this seems reasonable. I’ve written in the past about how promoting denser, infill development patterns in sprawling metro areas like Cleveland could go a long way towards improving air quality and limiting GHG emissions. To the extent that Furth is calling for these sorts of policies, we are probably on the same page.

Except, when you dig into his argument, it collapses like the proverbial house of cards. As the folks at Climate Nexus argued, “Instead of suggesting policy that would preserve more land to act as a carbon sink, Furth writes that California should instead relax the permitting process so that development is even easier.” And this is exactly what he argues. While it’s true that NIMBY-ism can inhibit the development of denser, multifamily housing (see: Washington, DC), it takes a certain amount of rhetorical gymnastics to assert that the fault lies with environmental regulations. I guess that’s what you get when dealing with stuff from Heritage.

Comparing fuel economy to land use planning

But none of this gets to the central thesis of Furth’s argument – that fuel economy standards are less effective tools for curbing GHG emissions than “streamlined” permitting and “more permissive zoning laws.” Why enforce regulations that cost the average family roughly $4,000 to only mitigate global climate change by a fraction of a percent?

Leaving aside the fact that Furth demands California repeal state fuel economy rules that even he admits were superseded by President Obama’s 2011 CAFE standards, does his main point hold water? Well, he never actually provides a shred of evidence to support his argument, for one. How can we know if the CAFE standards will cut GHG emissions less than land use reform if we don’t have numbers for the latter?

Fortunately, there exist a number of studies and reports that dig into the potential for land use reform to mitigate climate change. At the local level, several of these analyses have come from metropolitan planning organizations (MPOs), which are federally-mandated agencies that conduct transportation and environmental planning activities for urban areas.

Back in 2008, California lawmakers passed SB 375, the Sustainable Communities and Climate Protection Act, which requires every MPO in the state to develop a sustainable communities strategy (SCS) that outlines its approach to meeting its GHG emission reduction target. These targets are established by the California Air Resources Board (CARB). To what extent can land use planning by MPOs contribute to these these goals? And do the projected reductions in GHG emissions exceed those from fuel economy standards?

In a word, no. CARB estimated (PDF) in 2010 that regional transportation and land use policies can only account for one-sixth of the GHG reductions generated by federal CAFE and low-carbon fuel standards through 2020. That proportion will likely increase after 2020, as the full effects of those long-term policies are realized, but they still pale in comparison. Given that Furth is writing about California, you think he’d be aware of these data.

Evidence from outside California

Findings from MPOs in other states back up CARB. Washington, DC’s MPO found similar results (PDF). The region’s leaders set a goal of reducing GHGs 80% versus a 2005 business as usual (BAU) scenario by 2050. According to their analyses, enacting new land use and transportation policies at the metro level can only make up 3.3% of this 80%. Increasing CAFE standards to 99 could account for 30% of the reduction, however, making this approach 10 times more effective. While raising CAFE standards would likely lead to something of a rebound effect by making driving cheaper, the results are still impressive.

The Puget Sound Regional Council (PDF) – Seattle’s MPO – has also modeled the potential GHG savings from various policies. They found that more compact development and better pricing transportation could cut GHGs by 6% and 9% compared to BAU, respectively. Emissions control strategies, like stricter fuel economy standards and the electrification of the vehicle fleet, have the potential to cut GHG emissions by 25-43%, depending on how aggressive they are. Even in the more conservative scenario, these standards outperform land use controls. The benefits of land use policies take an outsized role in Seattle, as transportation accounts for two-thirds of the city’s total emissions, because it’s electric grid is so much cleaner than the national average. Accordingly, Seattle is the best case scenario for Furth’s argument, but it still falls short.

ghg savings from different scenarios

Potential GHG reductions from various policy instruments under different scenarios (courtesy of Puget Sound Regional Council).

 

And just to hammer my point home further, the Transportation Research Board (TRB) published a comprehensive report on this topic back in 2009. The authors modeled the impacts on GHG emissions from 2000 to 2030 and 2050 under two scenarios, which assumed that 25% and 75% of all new housing would be be built in compact development areas, respectively.

While scenario 1 only sees GHG emissions fall 1.3-1.7% by 2050, while scenario 2 bumps this number up to 8-11%. But, again, tightening CAFE standards wins the day. The study finds that adding aggressive fuel economy requirements to scenario 2 can increase the GHG reduction potential up to 39-51%. The report states, “In short, over the longer time frame (i.e. to 2050), the impacts of continuing improvements in fuel economy beyond 2020 on energy use and CO2 emissions significantly outstrip those from more compact development.”

As is so often the case, an op-ed emerging from The Heritage Foundation is tripped up by the think tank’s old nemesis – math.

In the effort to cut GHG emissions and battle climate change, we don’t need to privilege better land use planning at the expense of tighter fuel economy standards. We need to harness every policy tool at our disposal, and these are two great tastes that taste great together. While it’s true that better fuel economy can undermine some of the GHG benefits of compact land use, we should clearly pursue these approaches in tandem. For, in the long-run, more compact, mixed-use development and more efficient vehicles are both important tools for improving air quality, reducing transportation costs, revitalizing our neighborhoods, enhancing public health, and battling climate change.

What impact will climate change have on air quality?

sammis power plant
sammis power plant

The Sammis Power Plant near Steubenville, Ohio, which the PUCO agreed to allow FirstEnergy to continue operating through 2024 on the backs of ratepayers (courtesy of EarthJustice).

Though it’s hardly a secret that I view climate change as the preeminent issue of this generation, I usually try to bring some sobriety to the apocalyptic current that some of my fellow climate hawks bring to the table. Whether it’s casting a skeptical eye on the hype about climate change and conflict or challenging the use of the term “climate refugee,” I try to stay fairly level headed.

So it would seem reasonable that I would be somewhat wary of the hype surrounding the major new report from the U.S. Global Change Research Program on the public health impacts of climate change. I mean, as Kyle Feldscher of the Washington Examiner tweeted, somewhat snarkily,

But, here’s the thing, sometimes when Chicken Little screams that the sky is falling, you really do need to look up. And that’s the case with climate change. As this report lays out in tremendous detail, the public health implications of inaction are staggering, whether it’s the estimated 11,000 additional deaths per year from heat-related mortality, an increase in vector- and water-borne illnesses, or a spike in the frequency and intensity of disasters, things are going to suck unless we do something like yesterday.

Importantly, due to the lengthy atmospheric lifetimes of greenhouse gases (GHG), particularly CO2, some of these impacts are already baked into the cake. While the report makes it clear that we can stave off the worst effects on public health by taking immediate action to curb GHG emissions, the fact remains that we will inevitably have to adapt to that which we cannot mitigate and suffer that which we cannot adapt to. But since most of my focus is on air quality issues these days, I wanted to take a closer look at that chapter in the report.

Tracing improvements in air quality

First, it’s crucial that we note how much air quality has improved in the United States since the passage of the 1970 Clean Air Act Amendments (CAAA). According to the U.S. EPA, ambient levels of the six criteria air pollutants fell by a combined 63% from 1980 to 2014, including an astounding 99% for lead. All this occurred even as GDP grew by 147%.

This trend has paid significant dividends for Northeast Ohio. In Cleveland, for instance, the 3-year average for carbon monoxide (CO) from 1972-1974 was 17.3 parts per billion (ppb), well in excess of the 10 ppb standard. From 2012-2014, this value had fallen to just 4.3 ppb, a 75% decrease. Back in 1978, the 3-year average level of sulfur dioxide (SO2), which is generated largely from burning coal, stood at a mind boggling 497 ppb. In 2014, that level was down to 71 ppb, below the EPA’s 75 ppb standard.

The benefits of this dramatic improvement in air quality have been staggering. One study from the EPA found that, by 2020, the 1990 CAAA will prevent 230,000 premature deaths and generate benefits totalling $2 trillion. According to renowned University of Chicago economist Michael Greenstone, the 1970 CAAA extended the life expectancy of the average American by 1.6 years, totalling more than 336 million additional life-years. Here in Cleveland, we live, on average, 2.3 years longer because of this landmark piece of legislation.

But, as I’ve discussed before, a lot of people seem to think that these numbers mean we’ve moved beyond air pollution, that it’s something we’ve relegated to the past. That’s clearly not the case, given that a 2013 study estimated air pollution led to more than 200,000 premature deaths in 2005. In Cleveland, that number was 1,363, with the majority (62%) of deaths coming from electricity generation (466) and transportation (384). Clearly we have a long way to go, and incremental improvements in air quality will do a lot to winnow this number down further.

Will climate change affect this trend?

But that’s where climate change comes into play. The two primary bogeymen in the world of air quality are ground-level ozone and fine particulate matter (PM2.5). The formation of both of these pollutants depends heavily on meteorological conditions, particularly the former. When the conditions are right, ozone and PM2.5 levels can spike, with serious consequences for anyone who breathes air.

Now, obviously the most important thing that environmental officials can do is work to reduce emissions of ozone precursors, along with direct PM2.5 and its precursors. If there are simply fewer nitrogen oxide (NOx) and volatile organic compound (VOCs) molecules floating around, there will inevitably be less ozone in the air.

And this is true – to a point. That’s why the EPA estimates that, thanks to existing regulations like the controversial Mercury and Air Toxics Standard (MATS) and the Tier 3 Vehicle Emissions standard, ozone and PM2.5 levels will continue to decline. The agency projects, for instance, that ozone levels in Cuyahoga County will fall to 59 ppb in 2025 from 75 ppb currently.

Unfortunately, this fails to account for the impacts of climate change. Global warming is likely to make the types of meteorological conditions conducive to ozone formation – hot, still summer weather – considerably more common going forward. As the report’s authors note, “consequently, attaining national air quality standards for ground-level ozone will also be more difficult, as climate changes offset some of the improvements that would otherwise be expected from emissions reductions.”

To illustrate this effect, let’s look at recent history in Cleveland. From 2008 (when the EPA finalized its 75 ppb standard) through 2011, there were an average of 9.5 days each year when ozone levels exceeded the standard. This number plummeted further during the previous two mild summers, with 1 day and 3 days in 2014 and 2015, respectively. But then there’s 2012, the hottest year on record in the region. During that summer, we had 28 exceedance days, the highest number since 2002.

What will climate change’s impact be on air quality?

So what, exactly, does the report project? Well, it uses data from a 2015 paper by a group of EPA scientists that aims to “quantify and monetize the climate penalty” from higher ozone levels tied to climate change through 2030. Because the effects of climate change on PM2.5 are so difficult to suss out, the report focuses exclusively on ozone.

The authors use two global climate change scenarios, known as Representative Concentration Pathways (RCP) to estimate the effects. RCP 8.5 is a worst case scenario, while RCP 6.0 is slightly less pessimistic model that assumes we will take some action to curb emissions.

These models allow them to estimate the number of climate change-attributable, ozone-related premature deaths and illnesses in the US. While RCP 6.0 leads to somewhere between 37 and 170 premature deaths each year, RCP 8.5 could generate 420 to 1,900 additional early deaths. The authors find that “the economic value of these adverse outcomes ranges from $320 million to $1.4 billion for the RCP 6.0 scenario and from $3.6 to $15 billion for the RCP 8.5 scenario.”

climate change ozone impacts

The projected impacts of climate change on ozone levels and ozone-related mortality in the US for RCP 6.5 and RCP 8.0 (courtesy of Fann et al.)

These health impacts will not be distributed evenly, as the map above shows. Here the Midwest, particularly along the Great Lakes, significant global warming could drive ozone levels up by more than 5 ppb leading to tens or dozens of additional deaths. These findings are similar to those from a 2007 study (PDF) by Michelle Bell et al. in the journal Climatic Change. This study examined the impact of significant climate change on ambient ozone levels in 50 US cities by 2050. Bell et al. concluded that ambient summertime ozone levels would jump by 4.4 ppb, and every city studied would see an increase in the number of exceedance days by 2050. The average city would experience 5.5 more exceedance days per year, a 68% increase compared to the 1990s, while Cleveland could see a spike of 140%, from 7.5 to 18 days per year. The study uses the 1997 ozone standard of 85 ppb, meaning that the number of exceedances would likely be much higher for the current 2015 standard of 70 ppb. All told, ozone-related mortality was projected to increase 0.11-0.27%.

While this seems relatively insignificant, I should note that ozone is not a major cause of air pollution-related death here. If climate change was to have comparable impacts on particle pollution levels, these costs would increase by orders of magnitude. Unfortunately, this remains a real possibility. One study estimates that, while global PM2.5 concentrations may fall by up to 18%, they could increase by anywhere from 1 to 4 micrograms per cubic meter in the eastern US.

Ultimately, it’s not the projected number of additional deaths or asthma exacerbations that matters. What this report shows is that we have done an excellent job of cutting levels of harmful air pollutants, even as we increased emissions of a seemingly harmful one – CO2. But now, unless we take immediate action to slash the latter, all our great work on the former is at risk.

The startling costs of air pollution on unborn children

robert wyly cleveland pollution
robert wyly cleveland pollution

Industrial pollution obscures Cleveland’s cityscape in this 1960 photo from Robert Wyly (courtesy of Elvin Wyly).

In a developing fetus, one of the the last organs to form fully is the lungs. The National Institutes of Health (NIH) defines a preterm birth (PTB) as one that occurs before 37 weeks of gestation. This definition is, in part, due to the fact that the fetus does not begin to develop pulmonary surfactant, a vital lipoprotein that allows the lungs to remain expanded as one breathes, until around 30 weeks. All told, a child born before 36 weeks will struggle to breathe on his/her own.

PTB remains a serious issue in the United States. It is responsible for 35% of infant deaths, making it the single leading cause of infant mortality, and it can contribute to major cognitive and developmental disabilities. Given the vital role that lung function plays in infant health, it is clear that PTB directly affects a child’s ability to take in air. But what about the reverse? Could the air that a fetus (and its mother) breathes contribute to PTB? New research suggests that’s the case.

Drawing the link between air quality and preterm birth

Earlier this week, the journal Environmental Health Perspectives published a study from three researchers at New York University that explored the connection between air pollution and PTB. As I’ve noted in the past, there is a plethora of studies linking air pollution to low birth weight, PTB, and infant mortality. This study builds upon that literature by determining the proportion of PTB that is directly attributable air pollution.

In order to explore this issue, the researchers decided to examine the impact of the single worst criteria air pollutant, fine particulate matter (PM2.5). They assembled county level PTB values during 2010 from the Centers for Disease Control’s (CDC) WONDER database. Next, sing established epidemiological methods, they then calculated the proportion of PTBs in each county attributable to PM2.5 pollution, using a reference ambient concentration of 8.8 micrograms per cubic meter (μg/m3). This level of pollution is what the World Health Organization uses to determine the global burden of disease caused by outdoor air pollution.

Nationally, PTB rates have fallen to 11.3%, but they remain far too high. According to the study’s authors, 3.32% of all preterm births in the continental United States during 2010 were due to particle pollution. This amounts to 15,808 PTBs in that year alone.

Calculating the social costs of PTB from air pollution

But the authors did not stop there.  Theirs is the first study to quantify the economic impacts of this link. They developed estimates of the medical costs associated with PTB for children from birth through 5 years of age. To this value, they added the costs of lost economic productivity from reduced cognitive function and potential.

According to the study, the average premature child suffers an 11.9 point IQ decrement, which leaves them significantly disadvantaged compared to their peers.

Based on the best available data, the authors find:

These estimated numbers of attributable preterm births cost $760 million in medical care…and $4.33 billion…in lost economic productivity was also identified (based on estimated reductions in IQ and estimated consequences for productivity over a lifetime). In total, we estimated that $5.09 billion in preterm birth-related costs (medical care costs and lost economic productivity combined) could be attributed to PM2.5

Uneven distribution of costs

But, predictably, these costs are not distributed evenly among counties or demographic groups. The single highest fraction of PTBs attributable to particle pollution occurred here in Ohio, where 5.44% of all PTBs – 924 children in 2010 – are due to our polluted air. Compare this to New Mexico and Wyoming, states with drastically lower PTB rates, where the attributable fraction is just 0.12%. This leads to total annual costs of just under $300 million in Ohio: $253 million in lost economic productivity and $44.4 million in medical care costs.

Unfortunately, the authors did not provide supplemental data breaking down these attributable fractions and costs by county or metro area. They do provide a map that shows the percentage of PTB attributable to particle pollution by county, but it lumps all values above 5% together.

preterm birth from pollution by county

The percentage of preterm births attributable to particle pollution by county in 2010.

That said, Greater Cleveland has extremely high levels of both particle pollution and PTB. Cuyahoga County is one of just nine nonattainment areas for the 2012 PM2.5 standard, and Cleveland has the third highest PTB rate in the country. Pollution almost certainly accounts for a larger proportion of PTBs here then the state average. Additionally, based on data from the Ohio EPA, the annual ambient concentration of PM2.5 in Cuyahoga County during 2010 was 13.7μg/m3, 56% higher than the reference level of 8.8μg/m3 that the authors applied. Given this fact, I have to conclude that significantly more than 5% of PTBs in this region are tied to air pollution.

But let’s be conservative and assume that particle pollution is only responsible for 6% of preterm births in Cuyahoga County. That still means that the parents of 126 premature children born in 2010 can place the blame squarely on our elevated levels of particle pollution. If we raise this threshold to 10% – not an unreasonable assumption – this number increases to 209.

Additionally, Cuyahoga County accounts for 12.3% (2,093 out of 17,007) of all PTBs in Ohio during 2010. If we apportion this share, that means the county incurred $36.6 million in costs.

These numbers are equal parts dumbfounding and infuriating. The quality – or lack thereof – of the air we breathe day in and day out affects everyone of us here in Greater Cleveland. But it doesn’t just harm those of who have the means to choose where we live. It reaches into the womb and directly affects the futures of children who have never even taken a breath.

It’s well past time we stop pretending that air quality doesn’t affect every one of us profoundly and in a number of ways.

Idling cars are the tools of the devil

vehicle exhaust
vehicle exhaust

Vehicle exhaust contains a number of harmful pollutants, including fine particulate matter, and it is increasingly the primary source of urban air pollution (courtesy of Wikimedia Commons).

Thus far, El Niño has more or less kept winter at bay here in Cleveland. Well, that’s all changing this week. I guess once Mother Nature heard an overgrown rodent said we were getting an early spring this year, she got pissed.

Winter is back with a vengeance. We’re going to see temperatures drop to perhaps their lowest point of the year this weekend, and forecasters are calling for five or six separate fronts to bring snow over the next week or so. All of this should help to cut into our substantial snow deficit. As of Monday, the National Weather Service had recorded just 11.2 inches of snow this winter, roughly 26 inches below normal. That deficit has already shrunk by one-fifth, and it will continue to decrease.

The return of winter means a few things. First, our profuse application of road salt – with all its inherent environmental consequences – means that everything will adopt a fine coating of sodium chloride. Second, those of us walking through the city will trudge through unshoveled sidewalks and try to avoid the ubiquitous puddles of filthy, half-melted slush, which could either be an inch deep or the bottomless pit that Ozzie Smith fell into on The Simpsons. And third, people will idle their cars left and right. The other day, I walked past a St. Ignatius security guard who was idling his car in a parking lot on Lorain Avenue. When I came back an hour later, he was still idling his vehicle, all the while straddling three separate parking spots (including a handicapped space).

Now, I see the appeal of vehicle idling in the winter, but I don’t really understand the level of passion that idlers bring to the table. A few weeks ago, our local ABC affiliate, WEWS, reposted an article on why drivers should avoid idling their cars during the winter. Within a few hours, the pro-idling commenter horde descended to inform the reporters just how wrongheaded they were.

I know – never read the comments – but individuals insisted that “this is the dumbest thing I’ve ever read. Warming up car by idle (sic) is very good” and “cold oil will destroy your engine.” And, of course, the coup de grace: “Stupid article with gas prices at a (sic) all time low I could careless (sic) if I waste gas warming up my car especially when the windows are frosted or frozen.”

Let’s assume for a minute that the U.S. Environmental Protection Agency and basically every other authority on this topic, including car-makers, know more about vehicle idling than random internet commenters. Can we marshal the available information to help dissuade some of these pervasive myths on idling? Of course we can. So let’s do that.

“Warming up car by idle is very good”

This one is perhaps the most common idling myth, and, like all good myths, there is a kernel of truth here.

The EPA says that, on average, cars get 12% worse gas mileage during cold weather. However, this was a much bigger issue for older model years, particularly those that employed carburetors. Modern fuel injection systems automatically adjust to exterior weather conditions. Furthermore, cars warm up twice as quickly when driven as they do while stationary. It may be nice to sit in a car that you warmed up with your remote start on frigid winter mornings, but you’re not doing your car any favors.

“Cold oil will destroy your engine”

No, no it won’t. Again, this myth is ubiquitous, but it’s highly out of date. Modern, synthetic engine oils do not need to warm up first. They can flow properly at temperatures as low as -40°F. It may have been cold as hell last February, but we still live in Cleveland, not Barrow or Yellowknife.

Beyond this, idling is actually harder on your car than driving it normally. While batteries commonly stall out in cold temperatures, idling does more long-term damage. As they idle, car batteries continue to expend energy to the car’s components. This process leads to deeper engine cycling, which forces the battery to discharge more energy during normal engine operation. Discharged batteries, in turn, produce less power; this means that subsequent engine starts will require even more energy and take longer, which will shorten a battery’s lifespan.

Idling is hard on cars in other ways as well. It is true that a number of vehicle components, such as the starter, are designed to last a set number of starts. This would seem to suggest that idling your car would place less wear and tear on a vehicle over time. But again, this is not true. According to Natural Resources Canada, idling your car for just 46 seconds is worse and more costly than turning it off and back. In addition to straining the battery, idling engines do not run at an optimal temperature, which leads to the incomplete combustion of gasoline. This leaves fuel residue in the engine – not to mention producing more pollution – and can cut fuel economy by around 5%.

“I could careless if I waste gas warming up my car”

Would that I were so wealthy. But let’s consider exactly how much gas this gentleman – who I assume is Rich Uncle Pennybags from Monopoly – is wasting by idling.

Every two minutes that a vehicle spends idling consumes the same amount of gas as driving two miles. The average vehicle spends 60-73 hours idling per year, which accounts for 5-7% of total fuel use. Based on information from the Argonne National Laboratory, if a person idles for 10 minutes per day, s/he can waste up to 30-50 gallons of gas per year.

The true costs of vehicle idling

But, if you’re familiar with anything I’ve ever written, I’m more interested in trying to figure out the social costs of our idling habits. If everyone in Cleveland idles so profligately, what are the effect on the larger scale? How might all of that extra, inefficient fuel use add to the costs of air pollution and climate change?

With that question in mind, I decided to do some back-of-the-envelope calculations. According to a 2009 study from Amanda Carrico and colleagues, the average American idles approximately 16.1 minutes per day. More than half of that idle time (8.2 minutes) occurs due to traffic lights, congestion, stop signs, and the like, so we’ll eliminate it. This leaves 7.9 minutes of idling per day – 4.2 minutes for warming up the car and 3.7 minutes while waiting (to pick some up one, in the drive thru, etc.).

Next, we need to determine the population of passenger cars in the Cleveland area. According to data from the Ohio Bureau of Motor Vehicles, there were 2,130,794 passenger vehicles registered in the seven counties that make up Northeast Ohio last year. Of course, not all of those vehicles will idle that amount each day, so I will adjust these numbers to reflect the percentage of the general population that reported idling for warming (48%) and waiting (46%) for more than 30 seconds at a time in the Carrico et al. study.

We now need to figure out how much pollution and fuel cars consume while idling. Fortunately, the EPA has provided this information, though they do not have estimates for particulate matter emissions (which are, by far, the most harmful conventional pollutant in vehicle exhaust).

idling emissions calculations

Annual vehicle idling emissions in the seven counties of Northeast Ohio (author’s estimates).

Using information from the US Department of Transportation (updated to 2015$) and the EPA’s social cost of carbon, we can estimate the total public health costs of these idling emissions per year.

idling cost calculations

Total annual costs of vehicle idling in Northeast Ohio (author’s estimates).

So, by my (admittedly rough) estimates, vehicle idling carries social costs of more than $58 million per in Northeast Ohio alone. While the vast majority of these costs come from wasted fuel, there are still nearly $3.5 million in air pollution related costs. I could go down the rabbit hole of trying to estimate the morbidity and mortality costs associated with these pollutants, but I’ll spare you the arm-waving wonkery. But let’s not pretend that this wasted fuel has no effects. Oil extraction has significant environmental consequences throughout the process from well to tank, and – given that is a nonrenewable resource – all of this valuable fuel could have been put to more productive uses. Waste is waste is waste.

As all the available evidence and my calculations show, vehicle idling is far from beneficial. On the contrary, is wasteful, costly, and illegal in many places. If this one small component of driving carries this large of an impact on our region, can you imagine the aggregate costs of our cars? Comfort is important, but it’s not everything. So turn the damn engine off next time. Your lungs and wallet will thank you.

If you want to improve air quality, end the sprawl

interchange los angeles
interchange los angeles

The I-10/I-110 Interchange in Los Angeles (courtesy of Politico).

For centuries, people have fled the supposed squalor of cities in pursuit of the fresh air that is so vital for our health and well-being. Before Louis Pasteur’s development of germ theory, most scientists and physicians subscribed to the belief that miasmas – essentially the foul smells associated with rotting organic matter – were the source of major diseases. The cure for illness, they argued, was for people to escape cities to get fresh country air.

Doctors prescribed fresh air as a treatment for various illnesses into the 20th century. American physicians encouraged their patients suffering from tuberculosis to head West in pursuit of the restorative benefits of the clean air. This movement helped foster the growth of many prominent Western cities, including Denver and Phoenix.

The clean air premium

Today, we tend to refer to the deleterious emissions that plague many cities by a different term: air pollution. But that same underlying precept – that we need to leave cities behind in the pursuit of fresh air and better health – remains.

Multiple studies demonstrate that people view air quality as an amenity and are willing to pay for it. According to economists Kennethy Chay and Michael Greenstone, reductions in particulate matter during the 1970s were “associated with a $45 billion aggregate increase in housing values,” while a separate study found that Americans were willing to pay $149–$185 for a one unit reduction in particulate matter levels.

Clearly, we place a premium on the concept of “fresh air.” But could our pursuit of this good actually be making air quality worse for others?

How might sprawl affect air quality?

The link between our sprawl-based development patterns and air pollution seems pretty obvious on the surface. The more we spread out, the more we have to drive to reach workplaces, schools, stores, entertainment venues, etc. All of this adds to vehicle miles traveled (VMT), and each additional mile we drive increases our mobile emissions.

But perhaps it’s not as simple as it seems. Moving people away from the worst polluters was clearly beneficial for public health. And pollution levels are typically higher in denser areas with high traffic volumes.

Additionally, one of the main targets of the landmark 1970 Clean Air Act Amendments (CAAA) was vehicle emissions. As a result, cars purchased today run more than 90% cleaner than those manufactured 46 years ago. This trend has helped to offset the rise in VMT. Thanks to these regulations, emissions of carbon monoxide and ground-level ozone have fallen by 85% and 33%, respectively, since 1980, while particulate matter emissions have declined by more than one-third since 1990. These improvements have occurred even as VMT has nearly trebled from 1.12 trillion when the 1970 CAAA was signed to just under 3.14 trillion last year.

annual vmt

Rolling 12-month change in vehicle miles traveled in the US (courtesy of St. Louis Federal Reserve).

With all of this in mind, I decided to comb through the literature to see what the best available science says on the relationship between sprawl and air pollution, and what I found may surprise you.

Just kidding, no it won’t.

Sprawl and air quality: The evidence

One of the first scholars to explore this relationship, in depth, was Brian Stone, Jr., who published his findings back in 2008. He probed the relationship between the number of days that ground-level ozone concentrations exceeded the EPA’s National Ambient Air Quality Standard (NAAQS) and sprawl index scores for 45 large cities from 1990 to 2002.

Stone, Jr. argued there are three major reasons that urban form could affect ozone levels. First, it can influence emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs), the two pollutants that combine to form ground-level ozone. Secondly, sprawling cities are more prone to the urban heat island effect, which can increase the ambient temperatures in urban areas by more than 20°F; higher temperatures facilitate the formation of ozone. Thirdly, large, sprawling cities are more likely to have a broad ozone monitoring network, which may increase the odds that high ozone levels are observed.

The study found a strong, statistically significant link between urban form and air quality, even when controlling for weather conditions. According to Stone, Jr.’s results, a one standard deviation increase a city’s sprawl index score produced 5.6 more ozone exceedance days per year. In turn, a one standard deviation increase in population density – one of the four components of the sprawl index – was associated with 8 fewer exceedance days. Based on his findings, he notes that “urban form is significantly associated with both ozone precursor emissions and ozone exceedances…Overall, the most sprawling cities were found to experience over 60% more high ozone days than the most compact cities.”

To put that into perspective, Cleveland has a composite sprawl score of 85.62, meaning it is just over 14 units less compact than the average metro area. If it was as dense as Madison, Wisconsin (136.69) or Detroit (137.17), we would have had 11.2 fewer ozone exceedance days per year through 2002. Given that we averaged 20.5 exceedances per year from 1997-2002, this would represent a 55% reduction.

Strengthening the connection

Multiple subsequent studies support these findings. A 2013 article from Bradley Bereitschaft and Keith Debbage examined the connections between ozone and fine particulate matter (PM2.5) emissions and five separate sprawl indices. Each of the indices computed sprawl in a slightly different way, accounting for various measures of urban form. The authors folded these into two key measures – urban continuity (the degree to which the urban landscape is fragmented) and urban complexity (the degree of the “jaggedness” of the urban boundary).

The authors note that each of the sprawl indices produced a significant connection between sprawl and pollution levels. A one standard deviation increase in the most prominent sprawl index score was associated with 3.4% and 7.8% increases in ozone and PM2.5, respectively. The density of residential properties appears to be a particularly important correlate for air quality. Increasing residential density by one standard deviation lowers ozone and PM2.5 levels by 8% and 16%, respectively. This change in density can also lower on-road CO2 emissions by an average of 1.9 million tons. Using a social cost of carbon of $37 per ton, this produces social benefits of $70.3 million.

Bereitschaft and Debbage argue that “an increase in residential density might improve air quality and contribute to a reduction in per capita CO2 emissions at the metropolitan scale primarily by decreasing automotive dependency and tailpipe emissions.”

Additionally, the authors examined the connection between urban form and the direct emissions of NOx, VOCs, and PM2.5. Their results are striking. A one standard deviation rise in urban shape complexity increases PM2.5 emissions by 3,055 tons (12.4%) per year. Using EPA damage factors for on-road emissions, this additional pollution would cause 128 to 287 premature deaths and carry public health costs of up to $2.47 billion per year.

If more sprawl leads to worse air quality, will reversing that trend in Rust Belt cities lead to cleaner air? Stone, Jr. looked at this issue in a 2007 piece for the Joumal of the American Planning Association. He studied how shifting from a business as usual scenario to a more compact growth approach modeled on Portland could affect VMT and air quality in 11 Midwestern cities through 2050. By shifting from our current sprawl-heavy trajectory, Cleveland could lower household VMT by 9% and reduce emissions of CO, NOx, VOCs, and PM2.5 by anywhere from 7-9.2% each.

All the evidence points to one conclusion – sprawl is exacerbating air pollution. In our haste to find fresh air, we’ve simply made things worse for those who do not have the means to keep moving farther and farther out.

As Bereitschaft and Debbage put it, “Planning for density therefore becomes an issue of environmental justice, particularly at the metropolitan level. Simulations suggest that by relocating to peripheral suburban areas, residents might reduce their exposure to certain air pollutants…[while] simultaneously contributing to a decline in regional air quality by increasing the total volume of automotive traffic.”

I’ve argued before that, despite our poor air quality, almost no one in Greater Cleveland seems interested in talking about the issue and how we might solve it. Perhaps that’s because, unlike in the past, the real source of the problem isn’t just some large coal-fired power plant or steel mill. No, the problem is our individual driving habits. We’ve met the enemy, and it is us. Unless we face up to that fact, we aren’t going to change things for the better.

Air pollution adds to a number of Cleveland’s ills. So why does no one talk about it?

vehicle exhaust
vehicle exhaust

Vehicle exhaust contains a number of harmful pollutants, including fine particulate matter, and it is increasingly the primary source of urban air pollution (courtesy of Wikimedia Commons).

A few weeks ago, Rachel Dissell and Brie Zeltner from The Plain Dealer released their roughly 26-part series,Toxic Neglect,” which provided an incredible deep dive into the City of Cleveland’s chronic lead poisoning crisis. The series is truly outstanding journalism, something that is becoming increasingly rare in Northeast Ohio these days, and enough to max out your rage meter. If lines like “[Cleveland puts] more money into baiting for mosquitoes to curb West Nile virus and to prevent rabies in raccoons than we put into lead poisoning” and “national policy for decades has been to use primarily poor, minority children as household lead detectors” don’t enrage you, you don’t have a heart.

Dissell and Zeltner’s thorough investigation shines a light upon a major issue that is too often ignored in this region – the fact that at least 2,000 Cleveland children are poisoned by lead each year – and documents the City’s completely inability (desire?) to mitigate the crisis. They attempted to put a price tag on the problem, noting that lead reduces IQ and lifetime earnings potential, increasing healthcare costs, and contributes to violent crime in a city already plagued by them.

Dissell and Zeltner do an incredible job of displaying how the environment into which Cleveland children are born and in which they are raised irrevocably affects their futures. Their investigation centers on the city’s legacy of lead paint in its aged housing stock, the chief source of lead in the region. While airborne lead used to be an urban scourge, tetraethyl lead was finally phased out of all gasoline in the US in 1996. While much of that lead remains in our contaminated soils to this day, it is no longer the main culprit.

This series is just the latest in a string of great work from Zeltner, including earlier explorations of childhood asthma and infant mortality. But whereas it makes sense to minimize the role of air pollution in the lead series, this omission makes far less sense in the other two cases. We know that it is a important driver for both. But, for some reason, people in Northeast Ohio keep turning a blind eye to a problem that, quite literally, is all around them at all times.

It was with all of this in the back of my mind that I read a recent article in the journal Environmental Health Perspectives that examined the impacts of vehicle emissions on the cognitive development of children. The study, written by a group of public health professionals in the Boston area, focused on how exposure to pollution from traffic during late pregnancy and early childhood affects the brains of children later in life. The authors looked at the results of cognitive analyses for 1,109 children, aged 6-11 years old, who were part of an existing health study from 1999-2002. Because they tapped into this cohort, the authors had access to data on a number of variables, including household income, mother’s IQ, exposure to lead, and whether or not the mother smoked. Accordingly, they were able to control for each of these factors when conducting their analysis.

They split their sample into three main groups: those children living less than 50 meters from a major roadway, those living between 50 and 200 meters away, and those living more than 200 meters away. These distances are significant, as coarse and fine particulate matter rarely travels more than 10 to 100 meters in the air before settling back to the surface. This allowed them to examine how children growing up in close proximity to heavy daily automobile traffic would fair later in life. The results were stark:

Among children residing primarily in urban and suburban Eastern Massachusetts, prenatal residential proximity to major roadways (< 50 m) predicted lower nonverbal intelligence, verbal intelligence, and visual motor abilities in mid-childhood.

Those children living closest to heavily trafficked roads scored, on average, 7.5 points lower on nonverbal IQ tests, 3.8 points lower on verbal IQ tests, and 5.3 points lower on visual motor skills tests. In other words, the cognitive effects of growing up alongside a major roadway is comparable to an increase from the 5th percentile of childhood blood levels to the 95th percentile. In fact, at a 6.9 point decline in IQ from lead, the effects of traffic appear to be even greater.

Interestingly, the authors were unable to find a statistically significant effect of traffic-related air pollution on childhood IQ, perhaps because the effects of pollution were so tightly entangled with socioeconomic factors.

But the evidence does not stop there. In a 2008 study using another cohort of children from Boston, Suglia and colleagues looked at the connection between early childhood exposure to black carbon, a particularly harmful component of fine particulate matter, and cognitive function when children were 8 to 11 years old. They found that children exposed to high levels of traffic-related black carbon pollution saw their IQ scores fall by 3 points, even when controlling for socioeconomic variables, exposure to tobacco smoke, and blood lead levels. The authors noted that this IQ decrement was comparable to those experienced by children born to smokers (4 points) and by children poisoned by lead (1-5 points). Additionally, a separate 2011 study found a connection between prenatal exposure to traffic pollution and an elevated risk of childhood autism.

All told, mounting evidence suggests that children exposed to high levels of traffic-related pollution before and after birth are far more likely to have lower IQs and to suffer from developmental disorders. Just because we rarely see visible pollution like that from the mid-20th century these days does not mean that the problem is behind us.

It’s incredibly important for a city like Cleveland, which is struggling to break free from repeated cycles of poverty and abandonment, to come to grips with this reality fully, for two main reasons.

First, it may force us to recognize the consequences of our individual actions. Our driving habits are responsible for the majority of fine particulates and nitrogen oxide emissions in this region. We are part of the problem. Maybe the girl growing up on East 79th or West 98th is struggling in school, at least partly, because of the toxic environment into which she born. If we finally start to talk about this, perhaps we can make changes, even if just on the margins. Was driving half a mile to the store really worth aggravating her asthma? Was idling so you could run the AC while waiting to pick up your child worth the extra pollution you exposed him to?

Secondly, acknowledging these issues will force us to rethink our regional development choices. If we want to help improve the lives of low-income Clevelanders, should we really be, say, building a $331 million urban highway that will just bring more traffic, noise, pollution, and dislocation to communities that already have a surplus of them? Is that wisest use of our limited resources? Are we honestly going to help lift people out of poverty by exacerbating some of its causes?

We can’t drive our way out of a driving problem, and we can’t sprawl our way out of a sprawl problem. I don’t know if air pollution is topic that can bring all of this to the fore. Obviously I’m biased. But it’s also a ubiquitous problem in this region, and it plays a factor in a host of our pressing problems. It’s time to make it a permanent part of the conversation.

Study estimates that Volkswagen’s ‘defeat devices’ caused 59 premature deaths in US

vw emissions test
vw emissions test

A Volkswagen Passat undergoes emissions testing (courtesy of John Stillwell/AP).

Since the EPA announced on September 18 that Volkswagen had installed “defeat devices” in its so-called clean diesel vehicles for model years 2008-2015, analysts have been attempting to quantify the public health costs of this single action. A range of outlets from The New York Times to the Associated Press to Mother Jones offered up their estimates. (My personal favorite came from Brad Plumer at Vox, though that’s probably because I pointed him to the EPA technical support document containing the mortality factors that he used for his calculations…) Each entity used a different methodology and came up with different numbers, demonstrating just how hard it is to tabulate the real world impacts of pollution.

Well, last week, a group of researchers from MIT and Harvard published the first peer-reviewed assessment of the public health effects of the diesel scandal in Environmental Research Letters. This study finally gives us a reasonable baseline against which we can measure the true impact of VW’s deception, and the results aren’t pretty. According to Steven Barrett and colleagues, the affected Volkswagen vehicles will  account for an estimated 40.5 billion vehicle kilometers traveled from the start of 2008 to the end of 2015. Using the emissions estimates from the Institute for Clean Transportation, the organization that caught the defeat device, these “clean” diesel cars released 36.7 million kilograms of excess nitrogen oxides (NOx). These emissions directly contributed to the development of fine particulate matter (PM2.5) and ground-level ozone, both of which are clearly connected to premature mortality and a host of non-lethal health effects.

All told, from 2008 to the present, Barrett and colleagues estimate that VW’s defeat devices are responsible for roughly 59 premature deaths in the US. Additionally, the associated emissions led to 31 cases of chronic bronchitis, 34 hospital admissions for respiratory illness, and approximately 120,000 restricted activity days. Assuming that the statistical value of a human life is $8.5 million, the premature mortality attributable to VW’s actions totals around $450 million; this number does not include the social costs of morbidity.

Moreover, the authors acknowledged that the defeat devices remain on roads throughout the US. If they are not repaired in a timely fashion, the resulting excess emissions will likely cause an additional 140 premature deaths and public health costs of at least $910 million more. As The New York Times has noted, it may be extremely difficult for VW to get drivers to consent to the necessary repairs, as it may lower fuel economy and hurt performance. Fortunately, if VW was able to get each of the 482,000 affected vehicles in the country repaired adequately by the end of 2016, we could avoid 130 of the 140 anticipated deaths.

The aggregate costs of VW’s deception are truly astonishing. The authors estimates suggest that the excess NOx  emissions associated with the defeat devices made up 1% of total light duty vehicle emissions in 2015 alone. And, while it is true that the cars themselves are more deadly than what comes out of their tailpipes – the authors find the affected vehicles likely led to approximately 280 traffic fatalities – Barrett and colleagues explain that “the air pollution death rate from the excess NOx emissions is therefore ~20% of the accident fatality rate for an average US passenger car.”

Beyond putting a number on the social and public health costs of the VW emissions scandal, this study also represents the first time that anyone has attempted to illustrate the spatial distribution of the costs. As the map below shows, the excess NOx emissions were concentrated primarily in a handful of urban centers, including New York City, Washington, DC, Detroit, Atlanta, Denver, Houston, San Francisco, and Los Angeles. (Unfortunately the study does not provide a way for readers to estimate the distribution of premature mortality by location, as the map’s data are not granular enough for such an analysis).

excess NOx emissions VW defeat device

Distribution of estimated actual excess VW light duty diesel vehicle NOx emissions from 2008 to 2015 (courtesy of Barrett et al.).

Overall, this study is important for two main reasons:

  • First, it largely validated the estimates presented in the mainstream media to this point. As the authors note, media outlets had concluded that the emissions scandal led to anywhere from 16 to 106 premature deaths in the US. This range lines up quite well with the study’s confidence interval of 9.7 to 150 deaths. That’s surprisingly good, given the vast array of uncertainties and variables involved.
  • Second, the fact that there is now a peer-reviewed study linking VW’s defeat devices to premature deaths will likely be important for pending litigation against the company. Expect to see a number of lawsuits cite this study in their case against VW going forward.

The 1948 Donora Smog and the birth of air quality regulations

lunch time smog

Sixty-seven years ago today, residents of Donora, a town of around 14,000 lying along Monongahela River some 24 miles downstream of Pittsburgh, woke up to find a dense, yellow smog had blanketed the town. Donorans were accustomed to such smogs, as the town lay in a river valley ringed by hills that could reach up to 400 feet high. During the “smog season,” pollution from the industrial base of the city – including a steel mill and a zinc works – would collect in this natural depression and develop into smog until changes in meteorological conditions (shifting winds, rainfall) would dissolve the cloud.

But that didn’t happen on October 27. Or October 28, 29, or 30. Instead, a strong atmospheric inversion, which occurs when a blanket of lighter, warmer air flows in over heavier, colder air, sealed the smog in place. As this happened, emissions from the town’s factories, which included sulfuric acid, nitrogen dioxide, and flourine gas, continued to accumulate near the surface, instead of dissipating into the atmosphere. As the days passed, this blanket of toxic smog engulfing the town continued to get thicker and more noxious.

Given the prevailing views of the day, which suggested that air pollution was just a necessary byproduct of industrial progress, Donorans continued to go on with their lives. The high school football team played its home game that Friday; the Donora and Monongahela teams simply adjusted their tactics, with neither team throwing the ball. And the town even carried on with its Halloween festivities as planned. Workers at the steel and zinc mills continued to show up to work, despite the fact that they were producing the toxic emissions enveloping the town. The owners of the zinc works and steel mill rejected initial requests to shut down the factory as the days went by, and only agreed to cut back production on Halloween. This step occurred just as a storm blew into the area, helping to break the inversion and clear the air of the pollution.

All told, at least 20 people died during the smog, and, in the coming months, 50 more people died in the town than would have been expected under normal circumstances. But almost no one escaped the legacy of the smog, even those who did not succumb to its immediate impacts. The official epidemiological study conducted in the aftermath of the event concluded that “15.5 per cent of the total populace in the area were mildly affected; 16.8 per cent, moderately affected; and 10.4 per cent, severely affected.” The town’s overall mortality rate remained elevated for a decade or more. Relatively little changed for Donora or the country in the short-term. The town’s steel and zinc plants largely avoided being held liable, as investigators placed the blame on the extreme meteorological conditions that occurred. Whereas residents sued the steel plant for more than $4.5 million, U.S. Steel eventually settled for just $256,000, less than 6% of the damages sought.

To this day, the Donora smog remains less well-known than the Great London Smog of 1952, which, given that it affected a major metropolis, killed far more people (perhaps 12,000) and garnered considerably more attention. But Donora did lay the groundwork for air quality regulations in the United States. According to the Pittsburgh Gazette, Allegheny County regulated pollution for the first time the following year, and the passage of the 1955 U.S. Air Pollution Control Act, “the first federal legislation to recognize pollution as a problem,” can be linked to Donora (UPDATE: Per Ben Ross, author of The Polluters: The Making of Our Chemically Altered EnvironmentO, the 1955 Air Pollution Control Act was not the first federal bill to address air pollution. That can be traced back to the 1910 Organic Act, which created the Bureau of Mines. In fact, he noted, the 1955 act was a step backwards from the 1910 law in certain regards). The town’s museum commemorating the smog bears a sign proclaiming that “Clean Air Started Here,” while the town’s historical marker notes that “major federal clean air laws became a legacy of this environmental disaster.” Just as we think of the Cuyahoga River fire of 1969 as the impetus for the 1972 Clean Water Act (a story which is largely a fable), we should turn to Donora as we commemorate the 45th anniversary of the 1970 Clean Air Act Amendments that helped to end the legacy of these toxic smogs.

How VW forced drivers to ‘roll coal’ & what it tells us about the flaws in our emissions testing systems

rollin coal
rollin coal

Rollin’ coal (courtesy of Vocative).

Last summer, a few media outlets reported on a strange phenomenon that was on the rise in certain corners of the country. For whatever reason, a group of Good Ole’ Boys had decided that the best way to show how much they hated environmental regulations and loved fossil fuels was to alter their trucks’ exhaust systems to release massive amounts of black soot. This practice – called “rolling coal” – has inexplicably become highly popular in some communities; its official Facebook page has more than 18,000 followers.

For the coal rollers, tampering with the emissions controls on their trucks was a way to make their personal and political ideologies manifest. Never mind the fact that the exhaust they were spitting out is a known carcinogen. No, the coal rollers claim, the people who are on the receiving end of their soot cloud probably deserve to suffer the consequences because they have the audacity to walk, or ride a bike or, God forbid, drive a Prius. That this cloud of pollution could trigger a medical emergency for someone with a respiratory or cardiovascular condition didn’t matter, because pollution is freedom. Or something.

Fast forward to this week, when we found that Volkswagen had systematically been lying since 2009 about their supposedly “clean” diesel vehicles. When the company claimed that it had discovered a way to make its cars run on diesel, all while meeting US air quality standards, boosting fuel efficiency, and improving handling, people were thrilled. Nearly 500,000 Americans bought into the hype and purchased a clean diesel VW from 2009 to 2015. All told, there are around 11 million of these vehicles on roads globally.

Volkswagen and the inadvertent coal rollers

But, as we now know, VW sold these people a bill of goods. The company had installed a so-called “defeat device” in the vehicle software that allowed it to detect when regulators were conducting emissions testing. At this point, the car would trigger its emissions controls systems, allowing it to meet the standards set by the US Environmental Protection Agency (EPA). The rest of the time, the car knew to deactivate these controls, causing it to release 10 to 40 times more nitrogen oxides (NOx) than allowed by federal law. NOx are a family of harmful air pollutants formed by the incomplete combustion of fossil fuels. They can help form fine particulate matter (PM2.5) and are a key precursor to the formation of ground-level ozone.

Based on estimates from The Guardian, those 11 million affected vehicles may have released up to 948,691 additional tons of NOx than they would have if they complied with EPA standards. In the US, the 482,000 “clean” diesels on the road likely generated 2,700 to 11,600 tons of NOx. In effect, through its deliberate deception, VW forced its customers unknowingly to roll coal.

A number of observers have discussed the implications of this scandal, discussing, for instance, how efforts to make cars smarter and more internet compatible open them up for manipulation of this sort. But I want to focus on a different issue – how this episode provides an important insight into the the challenges inherent to the US’s vehicle emissions testing system.

Vehicle inspection & maintenance programs: A primer

As Americans began pushing their representatives to address the country’s air pollution crisis, environmental regulators developed ideas on how to tackle pollution from mobile sources. On the one hand, EPA developed a set of certification standards for all new vehicles sold in the country. The Agency developed a rigorous test – known as the Federal Testing Procedure (FTP) – to measure emissions from vehicles in operation. The FTP is highly complex, and largely involves running a car through various phases to simulate, among other things, driving on a freeway and driving in urban gridlock. If a vehicle manufacturer wants to sell its cars in the US, it needs to get EPA certification that it meets federal emissions standards.

federal test procedure

A graph showing the various components of EPA’s Federal Test Procedure for emissions testing (courtesy of US EPA).

But what happens once those vehicles are on the road? How can we make sure that they aren’t spewing out higher levels of pollution? And, if they are, how can we identify them and address this? That’s where vehicle inspection and maintenance (I/M) programs come into play. Congress first included language requiring vehicle I/M programs in areas with persistent air quality problems as part of the 1977 Clean Air Act Amendments (CAAA). Congress has amended these requirements since that point, most significantly as part of the 1990 CAAA. This bill required all areas designed as nonattainment for ozone standards to implement an I/M program. These programs typically required vehicle owners to bring in their vehicle annually or biennially and undergo some sort of tailpipe emissions test. These tests were generally a modified version of the FTP, such as the IM240, which lasts for 240 seconds.

For years, federal and state regulators promoted the benefits of vehicle I/M programs. EPA, in particular, reportedly considers it (see page 4-14) “one of the most important, if not the single most important, ozone control measure available to metropolitan areas.” According to the Agency, states that implemented its model I/M programs should see mobile emissions of hydrocarbons (HC), carbon monoxide (CO), and NOx  fall by 28%, 31%, and 9%, respectively. Given these numbers, I/M programs clearly appear to be a vital emissions control program, at least on the surface.

Challenges with vehicle I/M programs

But it’s when we get below the surface that things get murkier. As the VW case shows, technology exists to allow vehicle owners – or manufacturers – to actively cheat on emissions tests. But drivers don’t always need to have such malevolent intentions. As Dr. Donald Steadman, a prominent critic of I/M programs has noted, vehicle emissions can vary widely from one test to another – by an order of magnitude in some cases. Emissions also demonstrate a tendency to revert to the mean. In other words, a vehicle can exceed emissions standard on one day, but that same vehicle may dip below the standard on the next day, even in the absence of repairs. Drivers who failed the first test can pass the second through sheer dumb luck.

Even when drivers do get repairs to lower emissions, these repairs are often short-lived. If your goal is only to pass the test, you may seek out a low-cost repair to allow you to game the system. These repairs rarely last, ensuring that real world emissions may spike in the period between tests. And then there’s the drivers who simply choose to skip the test altogether. A number of states, including Ohio, require vehicle owners to pass an emissions test to register their vehicles. But some drivers bypass this option by registering the vehicle outside of the I/M program area or by selling it to someone who does. A 2009 investigation by The Akron-Beacon Journal found that 1 of every 5 vehicles that failed Ohio’s E-Check test in 2008 simply “disappeared.” Of these missing vehicles, nearly 20% ended up registered in counties directly adjacent to the E-Check area.

On-board diagnostics were supposed to fix the problem

These major issues with I/M programs led state and federal agencies to do a lot of soul searching in the 1990s. In an effort to address these challenges, EPA issued a rule in 2001 requiring all states with I/M programs to begin testing the vehicle’s on-board computers. These second generation on-board diagnostic systems, or OBDII, are installed on all cars model year 1996 or newer. OBDII systems are designed to sense issues with the vehicle’s emissions control systems and turn on an indicator light – the infamous check engine light – whenever issues with these components would lead to emissions that are 1.5 times higher than federal certification standards. For comparison’s sake, traditional tailpipe tests are set to fail vehicles whose emissions are 2-3 times higher than certification standards.

In theory, OBDII tests are great. Not only do they allow you to identify issues with emissions controls, they actually tell vehicle owners about them before their cars become major polluters. But, if you’re one of the 3 people who’ve made it this far, you may guess that OBDII tests aren’t a silver bullet either. On the one hand, because they are so restrictive, OBDII tests may fail vehicles that are marginal polluters and would have passed a tailpipe test. According to the National Research Council (pg. 99), up to 70% of all vehicles with an illuminated check engine light had emissions that fell below federal standards. This can push drivers, who are often lower-income, to make expensive repairs that do little to improve air quality. Additionally, OBDII tests may not be particularly reliable.  If a driver disconnects his/her battery before going to the testing center, the OBDII system will tell inspectors to run a tailpipe test instead. And at least one study suggests that, as ODBII systems age, they becoming more likely to malfunction. The odds that a vehicle would actually fail a tailpipe test but pass an OBDII test increases by 3.3% for each year it is on the road.

So what other options are available?

Ultimately, these facts demonstrate that the current vehicle I/M program faces a number of challenges that may compromise its effectiveness. So what options are available to address these shortcomings? One potential area for regulators to expand their efforts is the use of remote sensing device (RSD) technologies. Remote sensing, which has been around for vehicle emissions testing in some form or another for more than 20 years, allows regulators to measure a vehicle’s emissions while in operation in real world conditions. Rather than trying to simulate on-road driving, you bring the testing to the road. A number of states already utilize this technology in some capacity. Here in Ohio, the E-Check program employs RapidScreen vans, which measure a vehicle’s emissions as they drive by on the freeway. This approach can exempt a small group of very clean vehicles that complete 2 successful screenings within a 9-month period.

But RSD has the potential to be expanded further. The National Research Council found that RSD tests are able to identify “dirty” vehicles with a success rate of up to 96%. It’s telling that the International Council on Clean Transportation, the organization that exposed the VW defeat device, did so through the use of remote sensing devices while driving from San Diego to Seattle. RSD tests are also highly cost-effective (they cost less than $1 per test, on average) and can test a much larger number of vehicles in a shorter period of time. It’s worth noting that some prominent conservative and libertarian scholars, including Douglas Noonan and Daniel Klein, have been pushing to use RSD as part of emissions testing for years.

Observers have called for other alternative approaches. These include extending the required manufacturer’s warranty for vehicle emissions controls systems. Under the 1990 CAAA, all car manufacturers are required to provide 8-year/80,000 mile warranties for major emissions control systems, including the catalytic converter and OBDII. But that warranty is only 2 years/24,000 miles for other emissions components that can directly affect pollution levels. Extending component warranties to 200,000 miles would place the financial burden for controlling emissions back on the vehicle manufacturers and out of the hands of individual drivers. States could also follow California’s lead and provide repair subsidies to low-income vehicle owners. Dirty vehicles disproportionately end up in the hands of those people least able to afford expensive repairs. Providing them with financial support may incentivize them to get effective repairs to cut emissions. Perhaps the fines that EPA and the DOJ ultimately level on VW could help to finance the creation of this kind of program. Or these funds could go to finance alternative forms of transportation, such as to shore up underfunded public transit systems or improve bike and pedestrian infrastructure.

It’s nice to see that Volkswagen’s deception has sparked a conversation about the impact of mobile emissions on air quality. But it also provides an important insight into the challenges that environmental regulators face day in and day out. Hopefully this terrible episode can help bring about positive change by bringing attention to the issue and garnering support to fix the cracks in the existing system.