DNR Compiles Fine Particulate Pollution Report For 2005 - 2007

The Department of Natural Resources (DNR) Air Quality Bureau reports that its preliminary 2007 monitoring data indicates Iowa is in attainment for fine particulate pollution except one monitor in Scott County and one monitor in Muscatine County measured just above the Environmental Protection Agency’s (EPA) standard.

To attain the 24-hour EPA fine particulate standard, the 3-year average of the 98th percentile of 24-hour concentrations (known as the “design value”) at a monitoring location must be 35 ug/m3 or less. For the three-year period from 2005 to 2007, the fine particulate monitor at 300 Wellman Street in Davenport recorded a design value of 37 ug/m3, and the fine particulate monitor at 1409 Wisconsin in Muscatine recorded a design value of 36 ug/m3. Other monitoring locations in eastern Iowa had an average design value of about 30 ug/m3.

“Elevated fine particulate levels are a complicated problem, and we will need to employ local and regional pollution reduction strategies to meet EPA’s new fine particulate standard everywhere in the state” said Catharine Fitzsimmons, Air Quality Bureau Chief.

EPA lowered the 24-hour fine particulate standard from 65 ug/m3 to 35 ug/m3 on December 17, 2006. The more stringent standard provides greater protection to human health. Iowa had been in attainment with EPA standards for PM2.5 prior to 2007.

“We have adopted a cap and trade rule for power plant emissions that should help to reduce fine particulate levels across Iowa,” said Jim McGraw, Air Quality Bureau Planning Supervisor. “Industries have helped us develop an inventory of fine particulate emissions, which will assist in identifying effective approaches to lowering fine particulate emissions in areas where fine particulate levels are elevated.”

Iowa’s citizens can do their part by reducing energy consumption and driving less. DNR officials will work with the two counties to get the ambient air back incompliance with the EPA standard.

For the areas in the vicinity of monitors with design values that exceed the standard, the next steps will be to determine the extent of the nonattainment areas and seek input from affected stakeholders. The EPA is required to finalize the nonattainment area boundaries by December 18, 2008. For areas declared in nonattainment, the DNR will be required to submit an implementation plan to the EPA outlining the strategies that will be employed to bring the area back into attainment by 2012. The areas should be brought back into attainment by 2014 to meet the provisions of the Clean Air Act.

Particulate matter that is 2.5 microns in diameter or smaller scatters light easily and is often associated with smoke or haze when noticed in the atmosphere. Individual PM2.5 particulates are quite small; by comparison, a human hair is typically 50-70 microns in diameter. PM2.5 includes particulates suspended in the air, such as dust, dirt, soot, smoke and liquid droplets. Sources of PM2.5 include industrial and residential combustion, vehicle exhaust and wood burning. In winter, fog droplets at near freezing temperatures capture ammonia and nitric acid and give rise to fine particulates of ammonium nitrate.

The small size of PM2.5 allows it to easily bypass the human body’s respiratory defenses and become lodged deep within the lungs. As fine particulate levels rise, people with lung or heart disease, as well as the elderly and children, are the first to experience symptoms, which may include chest pain, palpitations, shortness of breath and fatigue. Elevated fine particulate levels can also aggravate asthma, decrease lung function and lead to premature death. Even healthy people who are active outdoors can be affected when PM 2.5 levels are high.

The preliminary 2007 data is under review by the DNR and is expected to be finalized by July 2008. Preliminary fine particulate design values for Iowa monitoring sites are available on the DNR website at www.iowacleanair.com/prof/monitor/monitor.html.

PM2.5 design values in the Des Moines area are expected to meet federal standards, but are not currently included in the report. This is due to additional calculations for incomplete data that must be approved by the EPA.

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