by Jackie Weidman, Susannah Marshall
Earlier this summer the Environmental Protection Agency proposed updated clean-air standards that will prevent tens of thousands of premature deaths. The proposal comes in response to legal action calling upon the EPA to update final regulations for particle pollution. This rule is in line with the Clean Air Act’s requirements to protect public health and improve air quality.
Particle pollution, commonly referred to as “soot,” is one of the deadliest forms of air pollution. This 101 details why it is essential that the EPA adopts the strictest rules possible to protect Americans from the dangers of breathing these particles.
For an overview of soot, check out this Ask the Experts interview with Dr. Dr. Christopher Lillis, an internal medicine doctor based in Virginia:
What is soot?
Soot is the common term for a type of particle pollution called PM 2.5—particulate matter that is 2.5 micrometers in diameter or smaller. Such fine particles are even smaller than dust and mold particles, or approximately 1/30 of the size of a human hair.
It is comprised of a variety of pollutants, including chemicals, acids, metals, soils, and dust, which are suspended in the air after emission. Soot can come in solid, liquid, or gaseous (“aerosols”) states.
How is soot produced?
Soot is a byproduct of burning fossil fuels, particularly coal. It is emitted by a variety of sources, including burning coal for electricity or industrial fuel, manufacturing, oil refining, and motor vehicles.
Soot is released into the air as either extremely small particles or liquid droplets. Some solid particles are emitted directly into the air while others are formed when gases form particles as they are carried thousands of miles from pollution sources.
Why is soot a problem for public health?
Soot poses tremendous harms to public health, particularly because of its size. Particulate matter is so small that it can easily enter your lungs and bloodstream, potentially causing damage in a number of ways.
The Environmental Protection Agency describes the process of soot harming the human body:
Microscopic particles can penetrate deep into the lungs and have been linked to a wide range of serious health effects, including premature death, heart attacks, and strokes, as well as acute bronchitis and aggravated asthma among children.
The American Lung Association adds that breathing particle pollution can potentially cause “cancer and developmental and reproductive harm.”
Nearly 6 million people in the United States live in an area with unhealthy year-round levels of particle pollution. The most vulnerable members of the population are children, the elderly, low-income communities, and people with pre-existing heart and lung diseases. Healthy adults, however, can also suffer from its adverse effects.
Why is soot an environmental problem?
Soot causes several environmental problems, such as haze and the acidification of lakes and rivers.
Haze is formed when sunlight interacts with small particles in the atmosphere. Soot is the primary cause of haze, which severely decreases visibility in U.S. cities and national parks. As a result the EPA estimates that visibility in national parks and other scenic areas in the eastern United States has been reduced from a 90-mile distance to just 15–25 miles.
Fine particle pollution negatively impacts the natural beauty of such national treasures by robbing us of color, distance, and hue, and negatively harms the health of visitors and residents. Haze can also hurt tourism by discouraging visits, which causes economic damage.
Particle pollution is also correlated to acid rain. The same compounds from soot that react in the air to form haze—sulfur dioxides and nitrogen oxides—can mix with atmospheric moisture to acidify precipitation. Carried by the wind or in the water, this acidified pollution degrades water quality by making lakes and rivers more acidic, depleting the nutrients in the soil and damaging sensitive farm crops, and changing the nutrient balance in river basins, along coastlines, and in forests.
Acidification through soot pollution can also stain stone and erode it, slowly discoloring and damaging important national monuments and iconic buildings.
Why is the EPA acting now?
A coalition of states and clean-air organizations sued the EPA for not updating its soot emissions standards within five years, as it is required to do by the Clean Air Act. The U.S. District Court for the District of Columbia told the EPA to issue new standards by June 2012 to protect public health and comply with the Clean Air Act. In accordance with this ruling, the EPA issued the new Air Quality Standards for Particle Pollution.
What does the new rule do?
The current limit is 15 μg/m3 (micrograms per cubic meter of air), which was finalized in 2006. The EPA proposed to reduce the soot limit to between 12 and 13 μg/m3, or a reduction of up to 20 percent. This safeguard would take effect by 2020. It would also additionally set a new standard for visibility in urban areas, which will either be 28 or 30 deciviews.
Existing standards for coarse particle pollution—particles that are between 2.5 and 10 micrometers in diameter—will not change.
Who will be affected by the new rule?
Emission reductions will be required from vehicles, power plants, and stationary diesel engines. The EPA will solicit reports from states to determine whether they meet requirements set forth by the new rule. The EPA will determine which states are in compliance with the rule by the end of 2014. Then, states will have until 2020 to meet the health standards. States may request extensions until 2025 on a case-by-case basis.
The EPA estimates, however, that 99 percent of U.S. counties will be in compliance with the rule without adoption of additional pollution-control measures. This is primarily because of other recent Clean Air Act rules that will also lead to reductions in soot, including the cross-state air pollution rule and the regulations to cut mercury and air toxics.
The approximately 20 counties that will violate the new soot protection standard will have to develop an implementation plan to reduce soot pollution to acceptable levels. State plans must specifically demonstrate how they will meet the standard.
What are the benefits from the soot rule?
Strong soot regulations can achieve tremendous health benefits. Strengthening the standards for soot could result in up to $5.9 billion every year thanks to the reduced costs associated with premature death and disease, according to EPA analysis. In other words every dollar invested in cleaning up soot pollution will yield up to $86 in health benefits. See the table below for a breakdown of the health benefits from the new rule.
So what happens now?
The EPA will be accepting public comments on the new rules until August 31, 2012. It also conducted two public hearings in July in Philadelphia and Sacramento. At these events most of the speakers urged the EPA to adopt additional protections from soot. This included a number of medical professionals.
To support the EPA’s proposed safeguards, you can submit comments here. The rule has to be finalized by December 14, and states will be expected to achieve the new limit by 2020. You can also view a video here on how reducing soot can protect public health.
Jackie Weidman is a Special Assistant and Susannah Marshall is an intern with the Energy team at the Center for American Progress.
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I wish you had included wood fires in the list of soot sources. It might not be a “major” source of soot pollution, but if you live downwind of a neighbor who burns wood, it might be your biggest source of soot pollution, resulting in many health problems.
Exactly, Mike. Thanks for making this important point. Individuals responsible for PM 2.5? Afraid so in the USA.
Improper use of a wood stove or wood furnace can certainly make smoke and particles. Generally that occurs when the fire is not hot enough. A small hot fire, rebuilt 3 or 4 times, is much cleaner than a large, cool, long lasting fire.
Similarly, the driver of a large diesel vehicle can effect the amount of smoke emitted, and I suppose, the size of the soot particles, by his driving techniques.
PM = picometer?!
Looks like someone at the EPA got their wires crossed seeing as the smallest atoms have dimensions of tens of picometers :)
and the diameter of a human hair is on order 50-100 micrometers….
One more environmental factor: when soot reaches the Greenland ice sheet and gets pulled down as snow, and then when a day above freezing melts the top inch of snow, I suspect that the soot will then be on top or under a tiny glaze of ice, absorbing sunshine every day and heating the ice sheet. The ice sheet’s natural moisture will keep the soot particles right on top. The released water sinks into the ice sheet molecule by molecule, while the fatter black particles get stopped from flowing downward. Melting a second inch of snow puts a second dose of soot on the surface. This aggregation of soot on the surface could build for years. Excess soot changes the surface reflectivity of the ice sheet. We see a similar effect when many days of sun hits an old snow pile loaded with street dirt and crud.
Looking at the geese photo above, I thought about the soot that those geese are exposed to. How does it affect their lungs, they need to work a peak efficiency to do what they do migrating those thousands of miles I would think?
Profits to the people, not the polluters… What is it that Corpro/People do not understand about the water and now the atmosphere, (Pending?), are the basic rights of the commons. Corpro/People are “people” now, Gia is not ours to sell. She belongs to the future generations. They want to dump in/on it! The price just went way up IMO. Hell, I have a $120/T charge for home garbage, $50 for compost makings! Waste water, even “rain run off” fees. (Guide lines here?) Corpro/People deserve a bulk rate of free? In fact get my tax subsidy support in the process! Get real…
What is a fair price to dump tons toxins in pristine waters and air? I, too seldom see that question asked, much less answered. Ain’t we talking real money here? Cutting school lunches instead?
Remember that “We the people” part? Does not “We” mean all of us?
Nice summary, but a few inaccuracies and omissions:
In the figure above, “PM” means “particulate matter” (not picometer). PM 2.5 refers to ALL particles whose diameters are 2.5 microns or less; PM 10 refers to ALL particles whose diameters are 10 microns or less, and thus includes the PM 2.5 particles too.
The EPA rule change would affect only PM 10. The reason is that PM 10 happens to be one of the original six “criteria” pollutants, addressed in the Clean Air Act. Since then, we’ve learned that PM 2.5 may be even more important healthwise than PM 10, but the original legislation didn’t cover PM 2.5. Interestingly, elevated ambient PM 10 levels probably affect public health much more than any of the other criteria pollutants (ozone, SOx, NOx, CO, Pb), but PM 10 has been harder to regulate because it’s also harder to measure. Finally, the make-up of the particulate is probably very important; the climate scientists like to say: Not all PM 10 is created equal. (In some places PM 10 is mostly sulfate; in other places, mostly nitrate; in still others, mostly carbon soot off vehicle tires.) The strategies for controlling each of these will be different.
Yeah, as several people have pointed out, there’s stuff that’s “off” in the article…
The proposed rule under discussion here is indeed for PM 2.5:
“With regard to the primary standards
for fine particles, EPA proposes to revise
the annual PM2.5 standard by lowering
the level from 15.0 to within a range of
12.0 to 13.0 microgram/m3 so as to provide
increased protection against health
effects associated with long- and shortterm
exposures. The EPA proposes to
retain the level (35 microgram/m3) and the form
(98th percentile) of the 24-hour PM2.5
standard to provide supplemental
protection against health effects
associated with short-term exposures.”
http://www.gpo.gov/fdsys/pkg/FR-2012-06-29/pdf/2012-15017.pdf
A couple problems in the blog post:
1. The EPA estimates some of the economic benefits from this rule can reach $5.9 billion per year, at a cost of $69 million, as the post says. But this does NOT mean that “every dollar invested in soot cleanup will yield up to $86 MILLION” in benefits. (Big typo…)
2. The health benefits table (figure 2) does not correspond to the health benefits of the proposed rule. The values correspond to a strengthened version advocated by the American Lung Association. Their economic benefits estimate, for that stronger version, is 50 times higher than the EPA’s $5.9 billion/year.