Court backs EPA on controlling airborne particles

An appeals court ruled yesterday that the Environmental Protection Agency had employed a valid approach to designating which areas of the country should take responsibility for controlling fine particulates — miniscule airborne motes that can be inhaled deeply into the lungs.

The opinion affects what had started out as a host of lawsuits brought by three states, nine cities and counties, and 10 groups representing power companies. By the time these suits had reached the U.S. Court of Appeals for the District of Columbia Circuit, they had been rolled into a single package known as Catawba Co., N.C., et al., v Environmental Protection Agency.

In regions where particulate air pollution exceeds federal standards, EPA can require especially strict controls on emissions of specks 2.5 micrometers in diameter or smaller. This pollution is known as PM-2.5. At issue in the current suit was who would be asked to ratchet down emissions when pollution values exceeded federal limits: just the municipality where air pollution was too high, this town and its surrounding county, or a whole metropolitan area that included potentially dozens of surrounding counties?

Because PM-2.5 pollution can travel hundreds — sometimes thousands — of miles before being washed out of the air, EPA chose the last option.

It reasoned that if, for instance, the middle of downtown Washington D.C. violated the PM-2.5 standard, not all of the pollution had all been generated in the immediate vicinity of the monitoring station that had recorded an excess. Outlying upwind sources would have contributed as well — often substantially. As such, EPA argued that it could and would indict outlying contributors as also violating the law — designating them as being in “nonattainment.”

So in December 2004, after finding that a number of major metropolitan areas violated the federal PM-2.5 standard, EPA designated 225 counties — most of them outlying contributors — as also violating the law. Although air in the outlying regions might meet existing standards, the upwind contributors were commanded to strengthen their controls on sources of PM-2.5. Those sources could be traffic, coal-fired power plants or other combustion sources.

Breathing high concentrations of fine particulates has been linked with respiratory disease (including asthma), heart disease and more. EPA had argued back in 2005 that if the 225 nonattainment counties reduced their PM emissions, as called for, the healthier air could prevent up to 15,000 premature deaths, 10,000 hospital admissions, and 75,000 cases of chronic bronchitis. Far newer toxicology data now link fine particulates with stroke (at least in diabetics) and with a deletarious reprogramming of genes.

But back in 2005, the upwinders saw no reason to be lumped in with the communities that had bad air-pollution readings. So they filed a flurry of lawsuits that charged as “arbitrary and capricious” those new EPA designations of upwind scofflaws. Moreover, the litigants charged, in designating these outer counties as violating the law, EPA had failed to uphold a key provision of the Clean Air Act, one known as section 107(d).

In its opinion yesterday, the three-judge panel sided firmly with EPA.

The litigants misread Section 107(d) or at least misinterpreted it, the court argued. It also pointed out that this section “is replete with the kinds of words that suggest a congressional intent to leave unanswered questions to an agency’s discretion and expertise.” So EPA gets wide latitude in determining how to determine which areas will be designated as being in nonattainment, the judges said.

Overall, the court concluded: “Faced with the complex task of identifying those geographic areas that contribute to fine particulate matter pollution, EPA both complied with the [Clean Air Act] and, for all but one of the 225 counties or partial counties it designated as nonattainment, satisfied — indeed, quite often surpassed — its basic obligation of reasoned decisionmaking.”

See also this week’s related feature on particulate pollution: Bad Breath

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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