Clearing the dust from the air by 2010

Last September, the Environmental Protection Agency (EPA) strengthened National Ambient Air Quality Standards (NAAQS) for the amount of very fine particulate matter (PM) pollution allowable in a 24-hour period. Several cities now are devising plans to comply with the new standards, targeting PM emission generators, such as vehicle exhaust and wood-burning stoves.

PM pollution is regulated under two particulate sizes, PM10, which includes particulates up to 10 micrometers in diameter but not smaller than 2.5 micrometers, and the finer PM2.5, particulates equal to or smaller than 2.5 micrometers in diameter. PM2.5 is of particular concern because the particulates can damage the liver, bone marrow and heart, and wind can readily transport the particulates over long distances.

The NAAQS 24-hour standard changed in September from 65 micrograms of PM2.5 per cubic meter to 35 micrograms per cubic meter and will be enforced in 2010. State and local governments that do not meet the new standards will have three years to design an EPA-approved state implementation plan (SIP) for reducing fine particle pollutants. The annual limits for PM2.5 levels (15 micrograms per cubic meter) were not changed.

In March 2006, the Washington-based National Association of Clean Air Agencies (NACAA) released a report detailing the sources of PM pollution — such as power plants, industrial boilers, vehicles and wood stoves — and how metropolitan areas can control it in their communities.

Current data indicate Sacramento, Calif., will not meet the new PM requirements. The Sacramento Metropolitan Air Quality Management District is beginning to reduce wood smoke, the area’s largest source of PM emissions, by requiring that residents replace old wood stoves with EPA-certified stoves upon the sale of the home, and prohibiting open-hearth fireplaces in new or remodeled homes, says Air Pollution Control Officer Larry Greene. The district also is developing a mandatory no-burn rule when the weather forecast indicates high-pollution days.

The Birmingham metro area already has failed to meet the annual standards, and it will not meet the new 24-hour standards based on current data, says Voris Williams, Air Quality Coordinator for the Regional Planning Commission of Greater Birmingham. City officials will be submitting an SIP for approval this fall, and they have begun instituting some measures to reduce PM2.5 and ozone levels, too. “Many of the sources for PM and ground level ozone pollution are the same,” Williams says.

She also says regional projects, such as an 81-bay truck stop in Bucksville, Ala., on the Tuscaloosa/Jefferson County line, will help reduce emissions. The truck stop allows truckers to connect to a console that provides heat, air-conditioning, phone and cable service while they sleep, rather than leaving their engines idling overnight.

The city also is participating in a regional program to test a remote emissions sensing system, developed by the Sheffield, Ala.-based Waste Reduction and Technology Transfer Foundation. The device projects infrared and ultraviolet light beams at vehicles on highway ramps to detect and record nitrogen oxides and volatile organic compounds — two components of PM2.5 — as well as carbon monoxide emissions, while a camera records license plates. The owners of grossly emitting vehicles, which are often old with low-income owners, are contacted and encouraged to make the necessary repairs.

The higher PM2.5 pollution standards are sure to direct more attention to efforts to clean up sources of air pollution. “Show me a threat today that causes 30,000 or 40,000 premature deaths per year,” says NACAA Executive Director William Becker. “That’s how horrific [particulate matter] is, and yet it is one of the least publicized threats to cities and counties.”

Annie Gentile is a Vernon, Conn.-based freelance writer.