Environmental Politics and Law

EVST 255 - Lecture 13 - Vehicle Emissions and Public Transit

Chapter 1. Asthma and Its Provenance [00:00:00]

Professor John Wargo: So I wanted to continue talking about air quality today and air quality law. And also to make some comments about Whitman v. American Trucker in response to a couple of questions. So with respect to Whitman, EPA in 1997 had proposed new PM and ozone standards. And both the Northeastern states and California supported these measures. And members of Congress from the Midwestern states did not support it. This is quite common with air quality standards.

It was unprecedented in EPA’s history for a single change in a national ambient air quality standard to have twenty-eight days of hearings in Congress. And finally, this was brought to court and made its way to the Court of Appeals in the D.C. Circuit. And the Circuit found that the standards were unconstitutional. It was eventually elevated up to the Supreme Court, and I read you the conclusion of the Supreme Court [Lecture 12].

But they also raised a separate question about the consideration of costs and whether or not costs should be part of the calculus. In “Section 109(b)(1) instructs the EPA to set primary ambient air quality standards, the attainment and maintenance of which are requisite to protect public health with an adequate margin of safety.” That seems rather clear. However, they went on, saying that “the respondents argue that many more factors than air pollution affect public health…In particular, the economic costs of implementing a very stringent standard might produce health losses sufficient to offset the health gains achieved in cleaning the air, for example, by closing down whole industries and thereby impoverishing the workers and consumers dependent upon those industries.” So this is unquestionably true, and the Congress was unquestionably aware of it at the time.

In considering the role of economics in decision-making and how that might be balanced against estimates of risk and the benefits from tougher air quality regulations, the court continued “Congress had commissioned in the Air Quality Act of 1967 a detailed estimate of the economic impact of air quality standards on the nation’s industries, communities, and other contributing sources of pollution…The 1970 Congress not only anticipated the compliance costs that could injure the public health, but provided for that precise exigency.” And Section 110 of the Clean Air Act permitted the administrator to waive the compliance deadline for stationary sources if sufficient control measures were simply unavailable and “the continued operation of such sources was found to be essential to the public health or welfare.” And Section 202 prescribed that emissions standards for automobiles could take effect only “after such a period that the administrator finds necessary to permit the development and application of the requisite technology, giving appropriate consideration to the cost of compliance within such period.” So EPA could decide that it’s time for a new air quality standard, but they could find that the economic effects were so intense that they could delay that and offer the industry the opportunity to retool or reorganize in order to develop the necessary technology, say a new emission control system in order to meet that new standard.

So despite this consideration of cost, the court found that the engine driving nearly all of Title I is Section 109(b)(1). And I commend you to read this, you can call it up on EPA’s website, that these standards have to be set to protect public health with this margin of safety to account for uncertainty in the risk estimate. So when in interpreting the statutory text, Congress does not, one might say, hide elephants in mouse holes. So they overturned the appellate ruling.

I want to take you back to where I left you on Tuesday and talk a little bit more about asthma and the prevalence of asthma and the finding by Mark Cullen and Eileen Storey at the University of Connecticut that between three and twenty-two percent of kids in Connecticut schools have been diagnosed by physicians. And by the way, one of the gold standards for recognizing an illness in a population would be looking at whether or not it had been diagnosed by a physician. And in schools, it’s interesting that if your child is on any medication, then you have to register those medications with the school nurse. So the school nurse has to keep very tight control. In fact, they maintain the meds in the nurses’ offices so that this is a really interesting and important and high quality method of record keeping. So Mark and I and several others wondered together about what the causes of the rise in asthma might have been during the 1980s and 1990s. And we started thinking about what had changed, whether or not kids might be exposed to different kinds of chemicals.

And I left you also with this lung section. And I wanted to come back to this, because I didn’t explain it very carefully the other day. So on the left is basically rat lung tissue exposed to low concentrations of diesel exhaust. And what you see is the coagulation between cells of the particulate matter, the carbon in those that are exposed at higher concentrations. Now what this suggests is that you might think about scenarios that would lead to higher levels of exposure. So what might those be? Well, we’re talking about black carbon in this case. So when are people more exposed to combustion byproducts? So one of the things you should always think about in terms of those that are more exposed would be occupational settings. So how about, for example, miners? So in coal mines, the coal dust is also carbon dust. But also, they use diesel generators to provide electricity to basically give energy to the jackhammers and to the lighting that they have in the mines. So the combination of unventilated diesel generator fumes on top of the coal dust leads to high exposures.

And what about truck drivers? It was interesting, after the study that I’m going to review with you in a few moments, I received a phone call from someone who had seen it, and they wondered whether or not they should get involved. This was the American Federation of Labor, the AFL-CIO. They were concerned that they were an organization or truck drivers that really might be one of the more highly exposed groups. Highly exposed because they sit inside their trucks all day long, and especially in urban areas where traffic comes to a standstill, you could expect that the exposures would be highest. So occupational settings are clearly one area where people might be more heavily exposed. A couple other human lung tissue samples that I wanted to show you with respect to black carbon, actually, only one.

So bringing you back to the map and the concept of the way that we understand the air pollution problem is really driven by these dots on this map. Could be in any state in the nation and you’d see a similar kind of map with the monitoring stations scattered about. And in some instances, they have a concentration where they think that the ambient concentrations are highest so that you can see them down along the southeastern part of the coast. And this is the area that is out of compliance. It’s a “nonattainment zone” for both particulate matter and ozone. And also, up in the Hartford area so that you see a collection of monitors. But also, they are trying to figure out the variability in distribution of pollution, so they put monitors also in parts of the state that are less densely populated.

So thinking about this, a group of us decided that we really wanted to understand what the air was like in the kids’ day. So rather than relying on the reports from these different monitoring stations, what if we took monitors and we put them on children and then we followed them through their daily routine, from the time they left home to the time that they came back to their house after school? So a group of us, including David Brown from the Centers for Disease Control and Nancy Alderman, who runs a group called Environment and Human Health, Mark Cullen, Susan Addis, the former Commissioner of Health in Connecticut, and Bob LaCamera, who is a professor of pediatrics here. This was the group that took this study on, along with some technical analysts at UConn that run the EPA testing lab. So all of the air quality measurements that are taken in the state go through their laboratory to make sure that they’re carefully analyzed. And I also left you with this chart so that you could keep in mind the idea that you’ve got a temporal variation in ambient outdoor air quality that appears to be driven and perhaps predictable, not just by month of the year, but also by hour of the day.

So what were these monitors like? Here’s an example. A gas canister, a little metal globe that was pulling in air at a preset rate, it had a vacuum in it. So that we were looking for about fifty-five different volatile organic compounds that we knew were part of diesel emissions. And by the way, we weren’t really sure whether or not the exposure was highest during the travel to school or whether or not their exposure and their risk would be highest within the school. So we used a variety of different pieces of equipment that could monitor chemicals that might be more concentrated either in traffic or in indoor environments.

In indoor environments, what kinds of chemicals might you be concerned about? Well, it could be, say, the chemicals in a photography laboratory or a chemistry laboratory, such as benzene or other solvents. Or it might be other kinds of cleaning products, or it could be pesticides. So that we tried to figure this out in a way that would point us to the most risky sources of exposure. And with respect to particulate matter, these carbon particles, this was the chart that we produced.

By the way, part of the story is that this is my daughter when she was about twelve years old. So she was the first guinea pig. She agreed to carry this BOC canister, but also she has a formaldehyde pump sitting here on her jacket. And she’s got a particle meter here to strapped to her belt. And she carried an IV cart that had a carbon monitor, an ethylometer that’s about the size of a microwave. So she walked around with this thing by her side all day long. And as a rather amusing anecdote on the side, when she first stepped on a bus, all the kids in the back of the bus screamed because of our post-eleven [post-9/11] sensitivity about what people might look like all strapped up in technical equipment. The bus driver threw her off the bus. And that’s when I realized that I should have called the superintendent and warned them what we were doing.

So here’s the outcome of our initial tests. We found that there was a burst of exposure early in the day to PM 10, and also a burst of exposure at the end of the day. But there were also increases that we saw during the middle of the day that really were not explained. And it took us a little while to figure it out, but the kind of particles that we were measuring varied by where the child was. So if they’re waiting for the bus or they’re on the school bus, one could presume that these were carbon particles. But if they’re just in the gym moving around, these could be dust particles. So if I had a chalkboard up here and I could take an eraser and just pat it against the board, you’d see a cloud of PM 10, particulate matter ten, move up into the air. The same thing with a gymnasium where you have say fifty kids running around playing basketball or some other sport. You get particles moving into the air. So we needed to discern the carbon particles from other kinds of particles.

So 600,000 school buses exist in the United States, and we also faced the problem of trying to figure out whether or not exposure during those high periods early in the day and late in the day were the result of going to school in traffic from the buses or were the particles coming from other vehicles? So I’ll tell you a bit more about that in just a moment.

So here’s a very quick summary of this study that was picked up by Good Morning, America when it was released.

GMA Host: — but now expected to get FDA approval.

Diane Sawyer [on video]: But now we turn back to this story. Important news for every parent of children who ride school buses. Later today, a new study from Yale University will be released, saying the amount of diesel fumes emitted by most school buses reaches levels that are substantially higher than the government standard. And those fumes are going directly into the air your children breathe. Our consumer correspondent Greg Hunter has an exclusive look at the study.

Greg Hunter [on video]: Twenty-four million children in America ride to and from school every day on a fleet of nearly 600,000 school buses. Most are powered by diesel fuel. And each of those children, on average, spends an estimated 180 hours every year on board one of those buses.

Here’s the bad news. According to a new Yale University study by Professor John Wargo, some kids are getting high levels of diesel exhaust from their school bus. Using ultra-sensitive monitors, which he placed directly on school children, Wargo took readings of the air quality around the children every minute throughout the entire school day. So you found out exactly what they were breathing in, minute to minute?

John Wargo [on video]: Yeah, we mapped it out. Actually, every ten seconds we took a reading.

Greg Hunter [on video]: Wargo’s readings showed spikes in the measurement of diesel exhaust at certain points of the day. His results differ from those of the EPA because the EPA measures air quality at fixed locations and averages the results over a three-year period. How much higher than the government’s acceptable level were you finding routinely?

John Wargo [on video]: Well, for short periods of time, we were finding levels that were five to 10 times higher than the government standard.

Greg Hunter [on video]: That’s a big spike.

John Wargo [on video]: It was a surprise to me.

Greg Hunter [on video]: There’s no telling exactly what exposure to this kind of diesel exhaust could do to a child’s health, but children with asthma, like thirteen-year-old Erin Paternoster, say they feel it every time they get on the bus. Did you ever have a time when you got on the bus feeling great and got off the bus feeling sick?

Erin Paternoster [on video]: Yeah, many times, I go on the bus and then I come off of it and I feel tightness in my chest or I can feel like I’m starting to wheeze or I feel like I need my inhaler.

Greg Hunter [on video]: Her father, John, is outraged.

John Paternoster [on video]: I’m not sure you’re going to find a parent who’s going to say, you know, we’re — we’re doing something right now that’s harmful to our children, let’s wait five more years before we do anything about it. Parents won’t stand for that.

Greg Hunter [on video]: But that’s exactly what the EPA is doing. In 2006, they’re going to implement new, cleaner standards for all diesel engines, including school buses. The reason they’re implementing cleaner standards, in part, they say, because diesel exhaust is likely to cause lung cancer, and they say the regulations will prevent more than 8,000 premature deaths and more than 300,000 asthma attacks. Wargo used two devices, one measured gases like benzene and the other measured ultra-fine particles such as soot. Wargo had 15 school children carry these devices throughout their school day.

John Wargo [on video]: What we found was in the morning, when they got on the bus, they were exposed to a high intensity of particulates. They tended to diminish during the school day. And then at the end of the day, there was another burst to their exposure.

Greg Hunter [on video]: Wargo also found the level of diesel exhaust aboard the buses was especially high under certain conditions, such as when the buses were parked end to end in front of the school, with the engines idling. I can smell the exhaust on the bus.

John Wargo [on video]: Yes, absolutely.

Greg Hunter [on video]: So it comes right out — The school bus industry says there’s an earlier study conducted in a Virginia school district last March that shows breathing the air on Fairfax County Public Schools’ buses poses no health risks.

GMA Interviewee: Obviously, one thing is caution the parents of the country, don’t be alarmed at this point. Let’s wait and make sure we understand everything before we make decisions that affect the health of our children and our own health ourselves.

Greg Hunter [on video]: Another industry group, the Diesel Technology Forum, argues that the diesel engines now being produced are much cleaner than the diesel engines of the past, and that with proper maintenance, diesel school buses pose no threat to riders. The costly process of upgrading a large bus fleet still poses a challenge to cash-strapped public schools, and even with the cash, it will still take time.

Diane Sawyer [on video]: Our consumer correspondent Greg Hunter joins us now. So you’re a parent, you see this, you want to do something, what?

Greg Hunter [on video]: One of the best things Dr. Wargo says that schools can do, and they do it in California and they do it in states like Connecticut, is having a no-idle policy. The school bus pulls up, they cut the engine off and that way they’re not kicking out all that diesel exhaust. Another thing they can do is stagger the times for the buses to come in, so instead of all of them pulling up, the kids getting on, and all of them pulling off, they stagger the times they come in and that will help alleviate the problem. He says it’s going to be kind of expensive retrofitting some of these buses, five to $6,000, it’s going to take time.

Diane Sawyer [on video]: What’s more important?

Professor John Wargo: Okay. A couple of asides. When we were both standing on the school bus, there was a film crew there with about six people. The fumes were — it was a day actually like this, with a high level of humidity. All of us got sick. All of us got sick within a matter of about five minutes. And it was curious, because the consumer correspondent, Greg Hunter, he didn’t believe that we were really picking up chemicals that were dangers. But after he and the entire crew felt nauseous and we all got headaches because we had lined the buses up one in front of another, and we the emissions were basically just building up as the time went by. He was clearly convinced that this was a more serious problem.

Chapter 2. Challenges to Monitoring [00:19:18]

So I want to take you back to the averaging issue, and remember that there’s twenty-four-hour averaging requirement over three years that’s in play with this standard. And that was represented by the graph that I showed you yesterday. If you took the data that we produced for just one child, as an example, and you average it over one hour or over eight hours, you see that all of the levels would be reduced. So your image of what the levels were would be down in this low range, missing experiences of much higher pollution. So again, the averaging issue played out in the way that we had to think about different kinds of strategies.

The other issue that I wanted to bring to your attention that surprised me was that the amount of time, the amount of exposure, was far higher than I could have imaged. So this diagram just shows you that the millions of hours per year spent on buses by kids in different states. And I want to point to just a couple of states here. New York has the highest amount of time spent by child hours on a bus, predominately because of the rural parts of New York and the relatively high population in New York. But compare that to California. California has a little bit less than half of the hours or the total exposure than New York. Now why might that be? Anybody have an idea? Sorry?

Student: [inaudible]

Professor John Wargo: Okay, well remember the population of California is 40 million people, so it’s a much larger population than New York. And I think that the answer is likely to be the way that residential population and communities in California are more closely clustered together than they are in New York state. So also, what we found that in places like Idaho, Wyoming, and Alaska that it’s very common for kids to spend two, three, hours a day on buses, as opposed to here in Connecticut, maybe an hour at most, forty-five minutes to an hour. So the pattern of land use really was driving the pattern of exposure that varied quite a bit state by state.

And one other aspect of this that was important was that kids that have disabilities, and they might be disabled for a whole array of different reasons, but kids that are disabled are often bussed to regional districts, regional school systems, that have very specialized expertise. So on average, kids with disabilities that are moved around to benefit from the specialized expertise, they experience a higher level of exposure. Some kids spend three or four hours per day going back and forth between these control centers.

And I mentioned earlier in the term that I got a call from a woman in Alaska who wondered about her child who was only three years old who she put just behind the driver’s seat. She was the driver of the bus. The child was asthmatic, and she was having trouble controlling the asthma with medications. And she wondered whether or not the school bus might be a problem. So I asked her, “Well, how long is your daily routine? How long does your child spend on the bus?” And it was eight and a half hours per day. So that thinking about these high-end exposures and which groups in the population might be susceptible is an important aspect of this.

So just one other thing that was interesting in terms of study design. And again, in terms of sampling strategy, first of all, we were monitoring individual kids and individual buses. And I just want to reinforce again the importance of thinking about sampling strategy, and remember the little 200-mile radius from the Nevada test site when the Atomic Energy Commission set up their sampling design in that way, and how everybody was fooled into thinking that those particles wouldn’t go beyond that area. There’s another defect in scientific thinking that led to confusion. In this case, we really didn’t understand whether or not the level of pollution that we were measuring was coming from inside the bus, from other traffic, or from other sources. And recall the other day I said within Connecticut we burn three times as much diesel fuel indoors to heat our buildings compared to what’s emitted from vehicles. So it was very important to us to get a sense of what was actually coming out of a bus.

So we set up a separate experimental bus route in a very rural part of Connecticut that was far away from any residential unit or any other source of carbon that we could think of other than carbon that’s kind of moving long distance and existing at low levels. So we would look at our meters and see that the levels were close to zero, and this was reflected also in the state’s monitoring facilities. And then we turned the buses on. And we saw an immediate jump in the particulate count and also in the BOC emissions within the buses after we did that.

We also saw a couple of interesting patterns. And my daughter, for example, was on a school bus. She was picked up near my house and she was taken to school. And there’s this increase in concentration, which is kind of curious. And then as she got to a school where she got off the bus for about ten minutes or five minutes until she was transferred to another bus. She walked about fifty yards away from the bus and then got back on the next bus and it picked her up and took her eventually to school. So this was a pretty good demonstration that the air quality within the bus itself was a serious source of exposure.

We also found kind of curiously if we looked at kind of the horizontal movement and we also looked at the behavioral pattern that we could figure out that elevation change across a route made a difference in the particle level within the bus cabin. So as a bus went uphill, it’s under load, it produces more pollution, emissions are quite a bit higher both for BOCs as well as for the small particles. In fact, I was coming to work the other day in traffic, and there was a truck next to me and the truck was using his engine as a brake. So we would accelerate in traffic, and I was right behind this bus, accelerate in traffic, I could see the dark black smoke coming out, meaning the engine is under load and it’s not operating very efficiently. And then the traffic in front of the truck would slow down and he would use his engine to brake the truck. It was under load again, and then you see the black smoke come up again. So remember that a cruising speed at about sixty-five, seventy miles an hour is the most efficient level of combustion for most diesel trucks and vehicles.

And by the way, I don’t think I mentioned this the other day, there are about 90 million diesel trucks and vehicles in the United States today. So this problem is much bigger than just the 600,000 school buses that I’m looking at in this study. We also found that if we compared the level of exposure to the kids on the bus inside the cabin to the federal standard, that they were experiencing levels that were quite a bit higher, sometimes twenty to twenty-five times higher for short periods of time.

And then we found this kind of a curious thing, that an idling vehicle collects more pollution inside the cabin than a moving vehicle. So there’s a ventilation process that occurs when a vehicle moves, unless the vehicle is moving in a train of buses that are coming into a school or leaving a school. By the way, most vehicles have no filtration system. Most trucks and buses have no filtration system for the air in the indoor cabin. And by the way, if you get to the point where you want to buy a new car, I would really encourage you to think carefully about the relative quality of air filtration. There are some vehicles now, the Japanese vehicles started to put filtration equipment in first, but it makes a significant difference to the quality of the indoor air. You can test that in a kind of an interesting way with respect to particulates and carbon. You can just take your finger, don’t clean your dashboard for six months for example, and then just take your finger and wipe it across and you’ll pick up a variety of particles that will come in because the interior cabin is so poorly filtered.

So this idling issue prompted us to think well one no brainer as a policy response would be to try to get the bus drivers to shut their engines off while they were idling. This was a much harder problem to crack with respect to trucks. Because trucks today are commonly on, their ignition is switched on twenty-four hours a day because the engine itself is providing electricity through a generator to refrigerate the cargo. But it’s also providing electricity for the main cabin. And for some long-distance haulers, especially independent operators, they basically live in their trucks. They will pull over to the side of a McDonald’s and sleep for six or eight hours. Or they’ll pull into a trucks stop, and most truck stops are not equipped with these electronic outlets so that they could plug their truck in and turn their engine off. So they’re burning fuel almost twenty-four hours and idling. And the level of emissions are higher in the engine while it’s idling. But also, I think that the truck drivers’ exposure is really quite a serious issue.

So we also found that the filtration equipment in these buses that were built in year 2000 was so poor, it virtually was large enough, the little spaces in the air filter were large enough so that you could stick a pencil point through it. So clearly, it wasn’t going to give any protection at all for low-diameter particular matter, PM 10 or PM 2.5. So there are a variety of factors here that you can read that influence the degree of concentration. Whether or not the windows or open or whether or not they’re closed, the engine type, the age of the engine in the bus, so that older buses are more polluting than newer buses are.

And one curious thing about this was whenever I do a study, I always assume that I’m going to get sued. And I was assuming that the large diesel manufacturing companies were going to give me a pretty rough ride. And I was really quite surprised, because they wanted to promote my work. They were really interested in having this become very common knowledge. And why might that be?

Student: Sell new engines.

Professor John Wargo: Sorry?

Student: Sell new engines.

Professor John Wargo: Sell new engines, that’s exactly the answer. They were interested in selling new engines that would emit lower levels of the particles that we were measuring. And put that idea together with the fact that most trucks have an active lifespan of three to four million miles and often thirty to sometimes even thirty-five years. So they were anxious that the standards be lowered so that they could sell more vehicles.

So there are a variety of lessons here. We were also measuring emissions when the vehicles were using a sulfur content in the fuel that was 500 parts per million. And remember I told you the other day that now the ultra-low sulfur fuels are available and in use as a requirement, completely phased in in the nation as well as particle traps that will take out some of the compounds of concern.

Now as you’re thinking about this as a policy problem and you’re thinking about it with respect to the Clean Air Act, you should also think about different parts of the country that are either within or out of compliance with air standards. So these exposures that are being experienced by kids or the drivers, they’re coming on top of background air quality problems. In other words, if you look here in Connecticut, you see that we are, the southern part of Connecticut, we are in an orange, where we’re exceeding the eight-hour ozone standard. And we were also, when we were doing the study, exceeding the particulate matter standard as well. So that on a day like this, you get many of the particles being rained out of the air. But on a still, humid day in the middle of the summer, you’re going to get a very high level background ambient — it’s called ambient exposure. So that these within-the-bus exposures or, you can imagine other kinds of pollutants in your daily life, are coming on top of this background level of exposure.

I was also quite surprised to find that diesel particles are measurable in any building in the nation. There’s an ambient background of diesel particles even in this room as we were able to discern just the other day. But I can’t smell diesel exhaust in the room today, but if you had the latest and most sensitive detection equipment, you could smell it. So we’re all experiencing this background level of exposure.

So one way of thinking about it is how many hours on the bus is going to lead to what kind of a total exposure? And so if the blue here is representative of the background level of exposure, maybe seventeen, eighteen micrograms per cubic meter of PM 2.5, then these other bus exposures in the colored segments are coming on top of that. So if you look way over on the right, for a child that’s on a bus for three hours, they would be experiencing the level of pollution that would be twice what the federal standard is. So as you’re thinking about how to create a health-protective standard, you need to think about these ambient average background levels that are being picked up and measured by the fixed monitoring equipment. But also think about just how daily behavior leads people to be exposed in very different ways.

Now, also, it’s curious that the European Union is moving much more rapidly to promote diesel vehicles and diesel engines, predominately to reduce CO₂ emissions. So that diesel now represents about twenty percent of the Europeans’ passenger fleet, whereas in the United States, it represents less than three percent. So that it presents a real dilemma to think through do we want to reduce CO₂ or do we want to be more concerned about lowering the level of exposure to these particulates?

So these kinds of questions can lead to policy recommendations. And for any kind of a problem, I want to encourage you to think about first of all, what’s the right target for your proposal? Is it the federal government, state government, local governments? Would it be voluntary standards that you might encourage to the corporations that manufacture these products? Or what could you recommend to an individual to reduce their exposure today?

Kind of curiously, in response to that last question, many parents responded to this study that got much more publicity than it deserved in terms of the investment in money. This study cost about probably 30 to $35,000 to do. But people all over the country stopped driving their kids to school, which was a problem. So I had to come up with some press releases that demonstrated that congestion at some schools was increasing because people were not putting their kids on the bus. And it was also increasing the risk of injury from accidents at the schools. So that driving your kids to school is not the right answer. You get many more vehicles arriving at the school, creating pollution that would be higher than what would be coming from the bus.

Chapter 3. Federal, State and Local Recommendations [00:35:30]

So recommendations to the federal government, retrofit diesel buses to ensure lower emissions. Put particle traps on them. And as the film segment showed, that’s expensive. That costs about $6,000 per vehicle to do. And it’s an important issue. And some of the states and the federal government have really stepped up in response to this. So who’s going to pay for this?

Well, it’s interesting that so far, I’ve been keeping track of what the state expenditures have been and what the federal government’s expenditures have been. And right now, we’re close to a half a billion dollars that’s been spent on school bus retrofits or substituting the lower emitting, newer engines for the older engines. So that requiring the buses to use ultra-low sulfur fuel at the time the study came out was a really important recommendation. Five hundred parts per million of sulfur as opposed to fifteen parts per million of sulfur produces a much, much higher level of particulate matter.

So testing tailpipe emissions, it’s kind of interesting that we have to have our cars tested for tailpipe emissions, but trucks and buses generally do not. So that they are exempt. In fact, they can be pulled over on the highway and they can be asked by a Department of Environmental Protection employee working for the state to turn their engine on, and they will hold what’s called a Ringelmann Chart up against it that gives them different levels of opacity. And they’ll hold that up against the sky and visually try to compare the darkness of the emissions to their chart to figure out whether or not they think that the truck is in compliance. Well, this is not the right way to go. There should be a much more intense and precise estimate that we have the technology available to conduct those kinds of emissions testing.

So the other thing to think here that is important on this list is that the federal standards, the fifteen micrograms per cubic meter, that is assuming a safe level, what the safe threshold would be with respect to outdoor pollution, not with respect to within-vehicle pollution or other indoor sources being added on top of that. So my belief is that these federal standards are not health protective because they basically are looking at the problem as one source at a time or just measuring what’s going on in the outdoor environment and forgetting that we spend ninety percent of our time either indoors or within vehicles.

So we also clearly need to expand the monitoring network. And the idea that we’re getting our image of the intensity of this kind of a problem by just relying on fixed monitors outdoors, it really makes little sense. So putting monitors on individuals and then following through their daily life, that’s going to give you a much more accurate representation of really what your exposure and risk might be. So this is a very expensive alternative. But it’s likely to be the wave of the future.

So a second target for this study has been state governments. So what could state governments do that the federal government could not do? Well, they could prohibit school bus idling by statute. And in fact, when this study came out, we proposed a law in Connecticut that would demand a maximum of three minutes for idling. And since we did that, there are twenty-six other states that have adopted this same idea. Save fuel as well as reduce pollution. So it’s kind of a double-win situation. Also, requiring more buses to drive shorter distances is another way of reducing exposure. So when most school districts, like we’re seeing today with respect to declining state grants and federal grants to school districts, what are they doing? They’re using fewer buses and they’re putting the kids on the buses for longer periods of time. So the routes are actually going in the wrong direction, leading to higher exposures.

And finally, local governments are really responsible for enforcing these idling bans. And we found in a couple of follow-up studies that there’s about a fifty-five to seventy-five percent compliance rate for no idling, particularly at schools. When we did the study, all the buses would pull up and they’d idle while the kids got on the buses or they would idle as the kids got off the buses to go into school. But now, it’s quite interesting. The monitors here turned out not to be people that worked for the government, but instead, the school teachers. Because the school teachers have long been angry, I hadn’t understood this, but they were angry at the way that the emissions were making their way into the school. And we found that many school systems had their ventilation systems set up so that they were pulling the air from the bus loading area into the school. And I had one superintendent tell me that she always knew when the buses were arriving, even though she was 250 yards away from where they were arriving on the other side of the complex because the air ventilation system was picking it up and redistributing it throughout the entire school. So just kind of thinking about building design as well is important.

Also, in my own town, in response to this, because we did some of the testing in the town, when the town built a new school two years ago, it decided to create a staging area, a separate parking facility where buses could go. And instead of all the buses training in at the same time or all leaving at the same time, they could stagger it, so that when one bus is following another bus, it’s simply going to be picking up the exhaust and distributing it.

Chapter 4. Less-Known Air Quality Problems [00:41:21]

So I wanted to give you just a sense of a couple of kind of air quality problems that you may not have heard of. This one was new to me. There was a CNN reporter whose beat is the Pentagon who called me the other day and he said, “Can you help me out? Can you help me understand what the threat is to people in the military from open-pit burning?” Open-pit burning of garbage right now is prohibited in the United States, although many people do it in their backyard. And open-pit burning is the primary source of emission of dioxins to the atmosphere. So people on the right-hand side of this in a barrel will stuff their garbage, their waste, into it and just burn it instead of having to pay for a trash collector. So you might save a hundred dollars per month if you did this.

So that what’s coming out is a product of very low-temperature combustion which is perfect for the formation of dioxins and furans. And dioxins, some of the congeners are known to be the most carcinogenic substances that we are now aware of. So that also you could think about how pollution would kind of gather on the surface nearby, could gather on foods or vegetable gardens, but also kids playing in a sandbox. So this is kind of a surprising source of our exposure to dioxins that are persistent, bioaccumulative, and carcinogenic.

There is a lawsuit that is being considered by a group of those in the air force that were responsible for maintaining these trash pits. They were responsible to throw the garbage in. And you can imagine what their exposure would be. And what is the primary component now of most of our waste? Well, it’s turning out to be, in terms of spatial volume rather than weight, it’s turning out to be plastics. So plastics when they’re burned, particularly polyvinyl chloride, is pretty well recognized to emit dioxins.

We have another phenomena going on in response to higher fossil fuel prices, especially in the northern latitudes in the country, and these are would boilers. People are buying wood boilers and basically not using their furnaces, their natural gas furnaces or their diesel fuel furnaces. So that these burn at a fairly low temperature and they also emit a variety of pollutants, including most of the particles in diameters that are quite small, just like tobacco smoke or like diesel emissions.

And here’s just one example of the effect of one household having one wood burner. And you can see this is spreading over an area that is now at this point in the photograph, it’s about almost a half a mile wide. And the concentration of particulates in this area, because I’ve worked on wood smoke, if you can see wood smoke at this level, the particulate concentrations are likely to be in the many multiples above that fifteen microgram federal limit.

So that this is a phenomenon that is increasing in prevalence and leading to really quite extreme exposures. I know this firsthand because I have a neighbor that installed one of these boilers. And he lives in a valley and I live on the hill above the valley. So every morning when the air is still because the sun hasn’t energized the atmosphere, it builds up in the valley, just like you can see in this case. It takes the sun to heat the atmosphere, and basically until about nine or ten o’clock, it elevates. But our house is filled with wood smoke from his house, as an example. And the compounds in wood smoke are just as dangerous as the compounds in tobacco.

You know, one other kind of idea that a student picked up on after this lecture a few years ago was the idea of mapping out healthy routes for exercise in urban environments. I mean, could you think about what the healthiest route would be through New Haven to ride your bike or to run? I mean, you certainly wouldn’t want to run, say, in New York City within Central Park, where you would have much higher air quality than you would if you ran, say along the Hudson River Parkway. So could you map out the healthiest running route? And the student did, putting our particle meters on a bicycle.

And one other thing that I’d like you to think about that we’re not going to have much time to consider is the kinds of consumer behaviors that can lead to rather intense exposures. Whether or not it’s the plug-in fragrances, the car air fresheners, and when I saw this, I mean, everybody knows about these. But the concept that you’re sitting in traffic and you’re really bothered by diesel exhaust so you put up a car air freshener that’s emitting volatile organic compounds that you may think are more pleasing than the diesel exhaust, but they are largely untested, they’re completely unregulated.

Also, the idea of aromatherapy, not knowing what those compounds are. Fragrances, when we talk about plastics next week, we’ll find that there are plasticizers that are hormonally active in humans and many species of mammals that are components of some of the most heavily-used fragrances. And also, laundry detergents. And many people are experiencing reactions to these fragrances. And we’re getting them in mixtures that really are not well understood.

So I’ll leave you with that, thinking that as you walk through your daily life, think about ways you could modify your behavior in a way that would reduce your exposure. Thank you very much.

[end of transcript]

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