EVST 255: Environmental Politics and Law

Lecture 12

 - Air Quality Law: Margins of Safety


The lecture describes the Clean Air Act and the way the federal government measures air quality as well as improvements in air quality. Professor Wargo reviews challenges in regulating air quality, reasons for lack of adequate enforcement, and approaches to setting ambient air quality standards. The lecture focuses predominantly on vehicle emissions, and the difficulty that regulators face when trying to decrease particulate matter expelled by cars. The public health impacts of poor air quality, particularly in urban areas, are discussed as well.

Transcript Audio Low Bandwidth Video High Bandwidth Video

Environmental Politics and Law

EVST 255 - Lecture 12 - Air Quality Law: Margins of Safety

Chapter 1. Challenges to Monitoring and Enforcing the Clean Air Act [00:00:00]

Professor John Wargo: Today, we’re going to embark on a discussion about air quality law. And I’m going to start with really an assertion by the Environmental Protection Agency that I’ve come to think of as a myth of sorts, when they have claimed that the nation’s air quality has improved dramatically in the past twenty-five years.

Well, how would you know if that’s true? How would you contest that? What kind of evidence would you want? And what we’ll find today is that your answer to this really depends upon what pollutants you choose to measure, what you know about the toxicity of different pollutants, where you measure the pollutants, do you measure them in a fixed monitor out in the field someplace in the middle of northeastern Connecticut? Or do you do it next to a highway in New Haven or Bridgeport?

And how you spend your time. Where do you spend the majority of your time? I bet it’s not where EPA measures pollutants. The majority of your time is spent indoors, I would guess, overwhelmingly indoors. And how do you behave indoors? And by that I mean, how would your behavior affect your exposure to pollutants indoors? These are all questions that became apparent late in the twentieth century, are really important to know whether or not law works.

And this law, the Clean Air Act, the pesticide law, it has a very technical character to it, and I think that you can understand by now in the course that environmental law is not just about making rules. It’s about understanding the environment and how it works and how it responds to different kinds of human stresses. And also, it’s about what we can do to relieve those stresses. So there’s a technical side to this that there is not in many other forms of law.

So is the air quality improving, and if not, why? So think about the different kinds of legal strategies and standards that have been designed to control air quality in history? Well one is land use and zoning. So thinking about how you’d segregate different land uses. So you keep the industrial facilities or say the military sites away from the residential areas. So this idea of segregation or buffering land uses where you know you have high levels of emissions from those where people reside away from schools. This was one of the earliest forms of attempted control. And there are examples in London back in the seventeenth century of prohibiting certain kinds of facilities, rendering plants or plants that produce a lot of smoke in the air from being in residential areas.

Another approach to controlling air quality is the idea if setting a ceiling or an allowable emission limit. So the idea that you would chemical by chemical set an allowable level of contamination in the air has become really central to the way that we’ve thought about trying to manage our health. So have these policies been developed in a way that’s precautionary, to prevent significant deterioration? And as you look at the structure of the Clean Air Act, you’ll see that the idea, prevention of significant deterioration, is a really critical concept. So we don’t — as a nation we’ve decided we don’t really want to make the air quality worse that it is. That we’re on a path toward restoration or improvement in quality.

We’ve also found that it’s important to think differently about mobile sources than it is about stationary sources. And quite frankly, if you were the administrator of the Environmental Protection Agency back in 1970 and you walked into this problem of having a zillion stacks in the county that were emitting dangerous chemicals, you would concentrate on very visible sources. So it’s a very different kind of a problem, and one where we’ve made more progress because we could identify the stack and we could put monitors on those stacks, than we face in indoor environments, when we don’t really have any understanding of the kinds of chemicals that we’re exposed to.

Trans-boundary flows of pollution have been traditionally very difficult to control. The Canadians are pretty upset with us in the way that we transfer much of the air pollution that is produced in the Midwestern United States up across central and northeastern Canada. As is New York upset with Ohio and the power plants in Ohio that are burning more coal and the pollutants from Ohio are moving into New York. So how do we control trans-boundary movements across state boundaries or across even local boundaries, or the most difficult situation would be national boundaries.

Property rights to pollute. This is an interesting idea. And really, this idea that you could set an allowable ceiling and instead of telling every person that lives in that region that they have to comply with a certain level of emission, that you put a cap on the total emission for that region, and then gradually you lower that cap down. So this is the idea of cap and trade. And it really grew out of an attempt to control acid precipitation associated with sulfur dioxides and nitrogen oxides that caused a whole array of problems, including loss of certain species.

So in the Adirondacks, I take a seminar to the Adirondacks in the fall every year. All the lakes above 2,500 feet in elevation don’t have trout in the Adirondacks because of the way that SO2 and NOx create acid aerosols that rain down and make those lakes too acidic for those fish to grow. Buildings around the world have been deteriorated, especially if they’re made out of limestone because of acid aerosols. The red spruce at high elevations in the Northeastern U.S., up on Mt. Washington or up in the Adirondacks or the Green Mountains, those red spruce are in decline. And the decline is caused by the fact that clouds hang over the tops of these mountain peaks and the fog itself is acid, so that it’s causing vulnerability to different illness. So capping and trading is now believed to be the more efficient way to reduce pollution. The idea began initially with Environmental Defense, when it was called Environmental Defense Fund, but it now has become really the cornerstone of attempts to control the CO2 problem that we face.

Technology forcing standards: so what if your technology is not capable of reducing emission to the level that you want it to be? Well, you can set an aspirational standard. By that I mean that you give an industry or a sector a certain period of time within which they would have to reduce their emissions. By the way, it’s only fitting that I can smell diesel exhaust in here today. I don’t know if anybody else can smell it. But it must be from the construction equipment. It’s a fitting topic for the air quality in the room. I should have my little monitor here. So the idea that you would create these aspirational standards was embedded into the Clean Air Act.

Fuel content regulations, I think it’s an interesting issue that we’ve been more concerned about what comes out of the stacks and what comes out of the tailpipes than we have about controlling the fuel and the process of its burning in order to reduce those emissions. So the idea of filtering what is coming out at the end of the process, the combustion process, as opposed to thinking more carefully about the nature of the fuel. We made serious mistakes in history, thinking about leaded fuel as an example. So lead was added to fuel to make engines more efficient and to knock less and to make them less prone to breakdown. But it spewed lead around the world. And recognizing that lead got into the bones of children and induced developmental and neurological disorders, that’s a very important story.

So fuel content regulation, in a way, there’s an interesting similarity to the way that we feed animals. So kind of neglecting residues that are in animal feed or neglecting the strontium-90 that was in the feed that went into cattle and then made its way to our dinner plates. It’s similar to neglecting the content of fuel and just not caring about where it’s going to go. So thinking about residues out there in the ambient environment as the target for regulation, as opposed to the underlying source, either the technology of the engine or the type of fuel that is burned.

So indoor behavioral regulation, we’ll see that after the break when we come back and look at tobacco regulation. So thinking about what is the right of the government to regulate what we do indoors in our houses as opposed to outdoors. And the idea of building certification standards and development certification standards. More commonly today than ever before, we’re seeing a variety of different land use regulations structured in a way that are designed to reduce energy consumption or to guide it in a way that produces less air pollutions. So here’s a suite of strategies that might be used to control air quality in a variety of different situations.

So just a couple of quick slides on key points relative to the structure of the Clean Air Act. We have Air Quality Control Regions. So each state has to set up a designated area as either in attainment or at non-attainment. And if you’re in attainment, you meet the National Ambient Air Quality Standards, NAAQS. And states have to put together state implementation plans. The idea being that states would have a better capacity to know the behavior of sources of emissions, and it would have a better ability to monitor what’s going on and to enforce violations of the statute.

So the state implementation plans have to have established enforceable limits, methods for acquiring air quality data, meaning that they’ve got to set up a surveillance system. Also, boundaries have to be well identifiable. They have to set up an enforcement program, and also have to demonstrate how they are controlling release of pollutants that could cross state boundaries. And also, they have to set up reporting requirements back to the Environmental Protection Agency.

So what happens if a state implementation plan fails? I asked the question of the head of the air quality division at the Department of Environmental Protection who was responsible for Connecticut’s state implementation plan. And he said, “Well, we could have our highway funds revoked or we could have them seriously diminished.” I said, “Well, how often does that happen?” Well, first I said, “Well how often are you out of compliance with the requirements, the limits for the national ambient standards or the hazardous air pollutants?” And he said, “Oh, quite often. In fact, southern Connecticut and especially in the New Haven region, is out of compliance for ozone and particulate matter routinely.” And I said, “Well, does that mean that the state has been forced to recommend to EPA to restrict highway funds?” And he looked at me and he said, “Well now, we never really would do that.” And I said, “Does that mean that EPA has never restricted or reduced highway funds to the state?” And the answer was no. So you’ve got a monitoring burden, you’ve got an enforcement burden that really is not working.

So you’ve got primary and secondary standards, and the primary standards have to be set to protect human health. And the secondary standards are set to protect environmental quality and property. And you’ll recall the effect of acid precipitation on building stone as an example.

Criteria pollutants are listed. So that this is a listing statute, just like the Safe Drinking Water Act. The analogy there would be the maximum contaminant levels. But also the Endangered Species Act. And because it is a statute where the chemical has to be listed before it gets any attention or is limited, then it has the same political dynamics as those other two statutes. Everybody fights about which chemical is going to be placed on the list.

Chapter 2. Hazardous Air Pollutant Provisions and Vehicle Emissions [00:12:56]

So there are also a class of chemicals, about 190, that are called hazardous air pollutants. And I’ll go through these just quickly. The criteria pollutants that were initially believed to be dangerous to health include particulates, SO2, NOx, carbon monoxide, ozone, and lead. And by the way, all of these chemicals are either emitted or they are created from automobile exhaust, just this one example.

But then we have this other category that’s called hazardous air pollutants. Asbestos, mercury, arsenic, beryllium, vinyl chloride, benzene, benzene is a known human carcinogen, radionuclides, coke oven emissions, and coal tars. So that there is this ambiguity in language that’s embedded into the act. Clearly, the criteria pollutants are dangerous, they’re hazardous. And the government has paid a lot of attention to these six compounds and not much attention to the hazardous air pollutants that include volatile organic compounds, some of which are ozone precursors.

So how are these standards set? What do they look like? Well it gets a big technical, and I’m not going to spend much time on it. But there’s been an increasing sensitivity about the danger of particulate matter if it is superfine. So originally, EPA went after particulate matter ten, which is ten microns in diameter, in size, and had neglected anything that was finer. So that eventually, standards were set for PM 2.5. But take a look at the units here. The units here are kind of fascinating.

So just take PM 2.5, because we’re going be talking about that with respect to diesel emissions. Ninety percent of diesel emissions are actually PM 1 or less, so that they are really quite fine. So it’s set at fifteen micrograms per cubic meter, and it’s hard to wrap your head around what that means. Or sixty-five micrograms per cubic meter, as a yearly average. And I’ll come back to the averaging issue. And for some of the pollutants there’s an annual average, for some pollutants there’s twenty-four [hour] average. And this is extremely important. So there’s a politic that surrounds the averaging period that EPA has allowed.

And by the way, when EPA wants to establish a new limit, how do they do it? Well, they publish a notice in the federal register. How many of you have ever commented on a Clean Air Act standards being proposed in the federal register? Really? You’ve done that?

Student: Maybe if I had any help from like Sierra Club or something, I’d do something like that.

Professor John Wargo: Well that’s great. You’re the first student in about ten years that’s raised his hand. But very few people pay attention to the federal register and very few people have the capacity to comment in a technical way that would be potentially effective.

So here are the ozone standards, the carbon monoxide standards and lead standards, and they all have different averaging periods. Well, it’s worth your reflection on how those averaging periods are established. And I’m not going to go into that except with respect to PM 2.5 today.

So the hazardous air pollutant provisions were largely neglected by the EPA. And Congress got upset in 1990 because only seven chemicals were regulated. By the way, there are six national ambient standards set, you know, PM and CO and lead that I just showed you. There were seven standards set for hazardous air pollutants as of 1990. And Congress said, “What? This doesn’t make any sense.” So how many air pollutants are there, anyway? Well, just in wood smoke is one example, or tobacco smoke, there are between 2,000 and 4,000 different particles, different compounds. So particles of different size. So the attention of government on so few compounds is really quite striking.

So Congress said, “What are you doing? What are you doing with the hazardous air pollutants?” And EPA said, “Well, we’ve just been so overwhelmed trying to figure how to manage emissions from stacks. And we’ve had a hard time in just dealing with six of the ambient standards, so we haven’t paid much attention to it.” So they established separate categories in the amendments of 1990. This set of amendments was probably the most important set of amendments in the history of the Clean Air Act. And it categorized minor and major sources and put into place the maximum achievable control technology standard. Maximum achievable control technology.

So it basically is forward-looking, thinking about the potential of technology, and in some instances, setting standards that are beyond what technology could meet. But offsets were also allowed to reduce hazardous air pollutants within plants. And what that means is that if you’re a refinery, say there’s a huge refinery with about a hundred different stacks that exist between Los Angeles and San Diego on the eastern side of the I-5 and it has so many stacks coming out of it that those refineries and other industries, large chemical companies, went to EPA and said, “Well look, we don’t want to have to meet these standards for every stack. For the ones where I’m emitting lower levels than what would be allowable, can I use that as an offset for the emissions for the stack that’s emitting more than is allowable?” And this provision was enacted to allow the companies to play a greater role in trying to figure out how they could reduce their overall emissions.

Well, today for the next twenty, twenty-five minutes, what I want to do is I want to focus on vehicle emissions. Because it’s extremely important to our energy future and our climate future, but it’s also extremely important to our health. It’s affecting us quite differentially based upon where we live, how we behave, and also our ethnicity. And this is because different ethnic groups have different background susceptibility. So all the principles that we talked about with respect to pesticides and strontium-90 about gee, you know, not everybody’s exposed in the same way, or not everybody is equally vulnerable. Or some people have background illnesses.

Well, this is a story in part about the genetic susceptibility of certain populations that have a higher prevalence of respiratory illness than others. For example, whites have a lower prevalence of asthma in the United States than do African Americans. And people of Puerto Rican descent have the highest in the nation. So that’s very difficult to explain. It’s difficult to tease out whether or not there’s a relationship between the smaller ethnic groups and where they live inside urban areas. There’s a separate debate about whether or not there’s a genetic characteristic that makes them more susceptible.

So I want you to think about the vehicle problem for a moment, which I think of as enormously complicated and enormously important. So that the way that we’ve been managing our consumption of fuel and vehicles and the way that we’ve used public subsidies to allow us to move more freely round our landscape has had just an enormous effect on our health, our behavior, as well as the quality of the environment. Two hundred and thirty-five million vehicles in the U.S., about 320 million people in the U.S., so that there’s now one vehicle in the country for everybody that has a driver’s license or is eligible for a driver’s license. So three trillion miles have been traveled in the past year. Two hundred billion gallons of fuel, 600 billion dollars per year at three dollars per gallon. And the average fuel efficiency of vehicles in the U.S. is about seventeen miles per gallon.

Some of you are helping me with a study of trucking and barging in an effort to try to think about reducing diesel emissions from trucks, tractor trailer trucks coming up ninety-five. Port Authority in New Jersey receives about five million of the containers that come in on barges to the Port Authority, and make their way up into Connecticut across the New York Border and move up toward Boston and deliver goods in southern Connecticut and Providence, Rhode Island, and also in the Boston area. So that one of the issues that we’re looking at is could we do something that would employ barges to move those containers so that it would avoid the adverse effects associated with trucking moving through the region, which is in part related to their climate influence, but also the really bad air quality in Connecticut surrounds the I-95 corridor and the I-91 interchange moving up toward Hartford. Those trucks, by the way, get about five to five and a half miles per gallon.

How about the lag in adoption of technology-forcing standards? So say that you were the EPA administrator and you decided you wanted to do something about this low-diameter particle and you published a regulation and went through the comment period, by the way, that is governed by the Administrative Procedures Act. And you mandated a reduction in say NOx and PM. In the case of particulate matter and NOx, this standard was proposed to be adopted back in the late 1990s, 1998. And eventually, it was adopted following litigation and following the Whitman v. American Trucker decision went into force. But it didn’t phase in to make any changes until 2006 and 2010 in requirements for engine design.

So you need to think about kind of the — last night in section I said it’s like the glacial pace of regulation. So supposing the science is really clear and it tells you that the current level of air quality or current emissions are really dangerous and that there’s a link between disease in the population and the emission levels, and you want to do something about it. Well, it’s going to take you probably between ten and fifteen years to see any difference at all in the regulations.

And what else is at play here? What’s the average life cycle of a car? Well now it’s approaching twenty years in the nation. And what’s the average life cycle of one of these long-distance trucks? Well, that’s getting close to thirty years. For some of them it’s even thirty-five years. And by the way, they don’t throw those engines away at the end of thirty-five years. They often move them into agricultural purposes, or the last resort of use for the least efficient diesel engine is now the fishing fleet. So that old engines don’t go away. This tells you that just adopting a new regulation that is technology forcing that is going to demand a new engine design that will emit less, it’s not likely to make a difference for a long period of time, given this long life cycle of the current vehicle stock.

Particulate standards. So they revised the standard, I said ‘98 a minute ago, it’s 1997. And it focused health concerns on mortality studies. And basically, they began to find that the finer particles are more dangerous. And this, I mean, thinking about it physiologically, anybody that has had physiology, this should be quite intuitive to you. So why would finer particles be more dangerous? Okay, yes?

Student: Absorbed immediately in the bloodstream?

Professor John Wargo: Well, absorbed immediately into the bloodstream. They are absorbed into the bloodstream. But why would finer particles be more easily absorbed than larger-diameter particles?

Student: I know also that small particles can act as a nucleus and attract other —

Professor John Wargo: Another good point. These small carbon particles act as a nucleus and they’re sticky and they attract volatile organic compounds. Yes.

Student: The small particles can get through your body’s natural defense mechanisms in your nostrils and stuff like that.

Professor John Wargo: Okay. The larger particles are filtered out higher up in the nasal pharyngeal cavity. The smaller particles can be embedded more deeply into your lung and they can carry, therefore, these other compounds along with them. So the finer particles are more dangerous. And we had started out with a regulation of PM 10, went to the regulation of PM 2.5. And now most people are thinking, “Wow, diesel emissions are ninety percent PM 1, why aren’t we regulating at PM 1 or even lower than that?” In part, it’s a detection technology issue. It’s more expensive to detect the finer particles. More cumbersome for states to try to set up a monitoring and surveillance program.

So what are the latest PM standards? Fifteen micrograms per cubic meter. And I want you to focus on one phrase here. These are daily averages and they’re then averaged over three years. Averaged over three years? Hm. Well, when I first read that and I hadn’t really studied any of the science, I said to myself, “Well, that must mean that the short bursts of pollution really don’t make any difference.” I always thought that it was not really a particularly good thing to hang out behind a truck or a bus on the highway that was blowing diesel smoke, and that there must be a better way to drive.

So that in this case, absolutely the opposite is true. The literature, the scientific literature, if you do a careful scan, it’s very clear that even short bursts of pollution can have an adverse effect on the respiration rate and also on people that have background illnesses. So if you look at the tunnel studies, for example, in Europe, in Switzerland in Germany, particularly through the Alps, where you have a lot of diesel truck traffic that move through those tunnels, and they’re often backed up in the tunnels so that the air quality in those tunnels is exceptionally bad. Well Lincoln Tunnel is another good example of that. So that they found that people were having respiratory symptoms, using medication more often or had to visit the doctor or be admitted to emergency rooms more often following these short bursts of exposure. So the short bursts actually count.

Read Whitman v. American Trucking, it’s a really interesting decision. The Clean Air Act, the Supreme Court concluded :unambiguously bars cost consideration from the standard-setting process.” Further, it requires EPA to set standards “requisite to protect the public health,” “allowing an adequate margin of safety.” So this is not a case like the early pesticide law of balancing risks versus benefits. No consideration of the cost to the trucking industry or to the auto industry or to the utilities can be at play as EPA decides what the level is supposed to be. By the way, just the claim that EPA had the responsibility to balance benefits caused this implementation of the PM standard to be delayed for three years while it was moving its way through the courts.

What about the health benefit of the new PM standards? EPA estimated that when they were fully implemented this year, hooray. Okay, they decided in 1997 that they wanted this new standard to protect health. So that it’s fully implemented this year. Eight thousand three hundred fewer premature deaths were estimated to be the result. Seventeen thousand fewer cases of childhood acute bronchitis. And 360,000 fewer asthma attacks. Well, this is per year, by the way. So EPA was estimating that every year of delay in the implementation of this standard, these are the health outcomes.

Now, how would you cost that out economically? Well how would you cost out say asthma? What factors would you consider in thinking about what the value to society might be if you wanted to put this question into a more utilitarian cost-benefit framework? Well, one of the things that you would certainly consider would be the medical costs, costs of medical care. So physician costs, emergency room visits, and also you have to be aware that those that are poorest in society have the least health coverage, and they tend to be the ones, if they’re asthmatic, that don’t get routine care. Severity of response is a function of whether or not you get routine care. And great studies about numbers of doctor’s visits related to numbers of hospital admissions. So the more routine care you get, the less likely you are to go into the hospital. So it costs society less, especially for people that are on Medicaid or Medicare.

So other costs that might be considered could be trying to figure out how to bring your child back up to speed in the classroom because asthma is responsible for more lost school days than any other illness among kids. Also, when a child stays home, when my daughter gets sick, either my wife or I have to stay home as well. So lost work days also should be accounted. Had an interesting question last night posed about, well what about the economic benefit side of the equation? So should you also consider some of the benefits of prescribing drugs or benefits to a hospital of having the profit that’s associated with use of the drugs or the medical services? So I mean, setting up the accounting system, it’s actually a very tricky business.

Chapter 3. Other Sources of Small-Diameter Particles [00:31:23]

Now, this problem of what’s coming out of vehicles has to be thought about in the context of what else is being spewed into the air. So small-diameter particles are not just coming from vehicles, they’re coming from power plants. So that this map of where the coal-fired power plants are located, this is an old map. But I’m using it just to make the point that there are other sources of particle emission, other sources of combustion. Forest fires in the Western part of the United States, in California, also produce similar kinds of particles. And so that the background level of PM in the Northeastern United States is really serious. Other sources include right here in New Haven, for example, the tankers that come into the oil tank farm here in the port.

And why is that significant? Well, it’s not as significant here as it would be say in Long Beach or San Diego, where you have a much higher intensity of shipment, but these barges do tend to burn high-sulfur fuel. So that we’re now burning sulfur fuel, diesel fuel, that’s about fifteen parts per million sulfur. That’s the new mandate under these new regulations. So the lower the sulfur content, the lower the PM level. Now, however, there are certain parts of the country that are allowed to burn 500 parts per million. And the military in Iraq is allowed to burn 3,000 parts per million.

By the way, that’s why if you ever see like a convoy of the National Guard going down the highway and you’re behind them in a car, it absolutely reeks. It’s because they’re burning this 3,000 part per million fuel, when your car or your diesel vehicle, your diesel car, was burning only fifteen parts per million. And there are parts of the country where it’s allowable to burn the higher-sulfur fuels. Surprisingly, including some parts of Alaska. So think about where else these particles are coming from. We also burn diesel fuel in Connecticut especially because we don’t have a good natural gas source. We burn it in our furnaces to heat our houses. It’s virtually the same kind of fuel, except it’s allowed to have a higher sulfur content. And also railroads along the ninety-five. So the railroad corridor, the highway corridor, on top of coal-fired power plant emissions, on top of commercial emissions, these are all sources.

Yes, question.

Student: Is high-sulfur content more efficient or cheaper? [Inaudible]

John Wargo: It’s cheaper. So getting the sulfur out of the fuel is a more expensive process. Question was, “Is high-sulfur fuel more or less expensive?” And high-sulfur fuel is less expensive. So it’s a matter of the degree of refinement of the fuel.

So that in Connecticut, I did a quick calculation and found that we’re burning about 230 million gallons per year of diesel fuel in vehicles. But we’re burning almost three times that amount in houses, in people’s houses. And that has not been the subject of regulation or attention on the part of EPA. That is interesting to me. So that we’re burning diesel fuel right in the — I’m burning diesel fuel in my basement in my house. I’d better be sure that my basement and my furnace are pretty well ventilated, and not everybody takes care to monitor how efficient their furnace is. They may let that go, especially in tough economic times like this. But your exposure could be really quite significant if you had a furnace that was out of efficiency.

So particle size definitions, coarse is greater than 2.5, fine is less than 2.5 but greater than 0.1, and ultrafine, just so that you know, a little bit of air pollution trivia. The diesel exhaust that you see here is only PM 10. So PM 10 is just about the limit of visibility, which is kind of curious, because most people think that diesel emissions are much cleaner than they used to be, that somehow we’ve managed to get rid of many of the smokers as EPA calls them with more efficient designs or with particle traps. But in fact, we’re producing, yes, finer particles, but we’re producing more of them. So the idea that you have more, finer particles that actually have greater surface area to lock onto these other kinds of volatile compounds that I was describing earlier. That is one hypothesis about why we saw the rise in asthma in the nation during the 1980s and the 1990s.

So what is in diesel exhaust? What is at 2.5 basically is elemental carbon, a smaller amount of organic carbon, some sulfates and nitrates, and some metals. Excuse me. Going the wrong way. Here is a diagram that shows particle size moving from ten part per million down to one-hundredth of a part per million, or micron, excuse me. And this is taken from Wilson and Spangler on a book on indoor air quality. So that you see the larger-diameter particles are taken out pretty much by the upper nasal pharyngeal cavity, whereas the lower particles do tend to get more deeply embedded in the lung.

Chapter 4. Widespread Asthma [00:37:04]

So let me talk just for a few minutes about asthma and asthma provenance in the country. So about seven million kids now have asthma, about twenty-two million adults. It’s the number one reason for school absenteeism. And there are other critical questions about what it means to have asthma, what the effects are on academic performance, socialization and depression. And I was teaching a seminar here at the Yale-New Haven Teacher’s Institute about seven years ago. And I asked one of the people in the class what the percentage of kids in his class was that had registered medications with the school nurse. He said he didn’t know, but he came back and he said it’s about twenty-four percent of his kids in his class had been physician-diagnosed as having asthma. I said, “Twenty-four percent? That’s really extraordinary, that’s beyond epidemic.” So thinking about how this has escaped public attention is really quite interesting.

Mark Cullen, who’s now head of internal medicine at Stanford, and I worked on an asthma report along with a group called Environment and Human Health. And when Mark was here in internal medicine and headed up the Environmental Medicine unit, we did a survey in Connecticut of asthma prevalence in schools. And we found it did range between three and about twenty-two percent school district to school district. This is really quite striking. We also found that the urban schools had the highest prevalence rates. So we then thought about okay, well what does this mean relative to what we were thinking about in air quality? And this is an aside, by the way.

And I just wanted to show you the picture of a slice of a lung tissue that demonstrates what happens to the carbon when it’s inhaled. It doesn’t just go away, it doesn’t just dissolve. It will sit in your lung. And I’ve talked to many of the surgeons at Yale-New Haven who do sections and treat people with lung cancer. And I got into this because my dad had lung cancer, and I was thinking about different forms of treatment that he might consider. And I asked the question, “Do you notice a difference between people that live in New Haven and people that do not, assuming that the two groups are both nonsmokers?” And he said, “Oh yes. You can tell. You can tell by the grayness. You can tell by the presence of these carbon particles in the lung tissues.” They take certain sections of the lung out for those that have operable lung cancer.

So then I started thinking about what other kinds of background illnesses would make one susceptible to air pollution? And they would be people that were asthmatic, kids and adults, those with chronic bronchitis, those with emphysema, those with coronary heart disease and diabetes. And if you look on the right-hand side of this chart, you’ll see that the number of people in the United States diagnosed with these different illnesses, and you see the numbers are really quite striking.

And you might pause and say, “Well what do diabetes and coronary heart disease — ” But this is very important to pay attention to. So fifteen million people diagnosed with coronary heart disease. Well, they found that diesel emissions have the capacity to move through the bloodstream once they’re inhaled, to cross the blood-brain barrier, and to move very widely through the body. And they also tend to slow down blood flow. They tend to act as a minor coagulant. So that you can see an increase in hospital admissions for coronary events following pollution episodes, particularly during the summer months in the Northeastern United States.

So I’m going to run out of time in a few minutes. But I wanted to give you a sense of how we understand air pollution in the state. And we basically do this by the monitoring system set up by the state implementation plan that sets up these fixed monitors at different sites. So there’s one right over on State Street. There’s one Stiles Street, which is just across the Q Bridge. And you see that they are capable of picking up different kinds of pollutants. The Stiles Street Station picks up PM 2.5 and PM 10, another one in New Haven picks up PM 2.5, Madison Hammonasset State Park picks up 0.03 down here on the shoreline.

And you might say, why Madison? And actually Madison has some of the highest reading in the state for Ozone. And it happens to be because the rush-hour traffic in New York generally gets to this part of Connecticut by about noon, when the sun is highest in the sky. So you have the ozone precursors coming in from New York, taking maybe four or five hours after rush hour to get here, and then you get the sunlight coming down and acting on them in a way that produces the ozone. So that the concept here is we have about thirty different stations set up with fixed monitoring.

So what do the monitoring sites tell us about pollution and how variable it is across time? So this is a day from midnight to midnight going across the bottom. And what you see here is different months of the year represented by the different colored lines. And over here, you see the PM levels. And PM 2.5 has the standard of fifteen microns as being the federal limit. That’s when it’s averaged over a full day. And these estimates are averaged over a day. And what you see here is that some months are clearly dirtier than other months are. For example, June tends to be, in this year at least, June was more polluted than say December was. So that there are certain climatological patterns that are behind this.

But you also see something else in this chart which I think is quite curious. You see this effect. You see a decline coming in the early morning hours. You see a rise coming around the rush hour. You see a decline that’s more in some months than others coming back down for the lunch hour and then picking back up. This is an artifact of the way that we drive vehicles and how we’re all at quite a similar schedule.

And I’m going to leave you today with this diagram saying to you that you need to think very carefully about these averaging periods. So I measure particles at ten-second intervals. And they’re represented by these blue squares. And if you take the same data and you average that data over a minute, you get the pink squares. If you take a five-minute moving average, you get the yellow. If you take a one-our average, you get the purple. And you get the red if you average it over eight hours. The PM 2.5 standard demands that the data be averaged over twenty-four hour periods and then averaged over three years. So basically, the way that EPA would read data would be over this twenty-four hour average over three years. And you can tell from that that it would compress everything so that all of these values would be invisible. Even if you had blocks of time, like three, four hours, were pollution was exceptionally high. So when you put that story together with the idea that scientific literature is telling us that we need to pay attention to these short bursts of pollution, predominately because people are experiencing medical effects that are now causing them to seek medical attention.

Okay. That’s it today. We’ll come back on Thursday.

[end of transcript]

Back to Top
mp3 mov [100MB] mov [500MB]