Fine particulate and sulfur dioxide pollution levels in excess of the U.S. Environmental Protection Agency (EPA) health threshold were measured this morning in the city of Muscatine. Conditions are expected to improve by tomorrow morning, with wind direction shifting as a winter storm passes through the area.
The Iowa DNR recommends that Iowans living in the neighborhood of Garfield School in Muscatine with respiratory or heart disease, the elderly and children limit prolonged outdoor exertion until air quality conditions improve.
The EPA’s 24-hour health threshold for fine particles is 35 micrograms per cubic meter.
At mid-day today, fine particle levels averaged 57.5 at Garfield School in Muscatine. Mid-day levels in Davenport, Iowa City, and Lake Sugema were lower, 12.6, 12.3 and 10.9 micrograms per cubic meter respectively.
Sulfur dioxide levels greater than the EPA standard were also measured at the Garfield School site yesterday and this morning. The one-hour sulfur dioxide standard is 75 parts per billion (ppb). A daily maximum one-hour value of 139 ppb was recorded yesterday. The highest hour recorded so far today was 158 ppb at 3 a.m. this morning.
Fine particles are emitted by vehicle traffic and other combustion sources, and are formed by chemical reactions in the atmosphere. Sulfur dioxide emissions are primarily caused by coal combustion at industrial sources.
EPA’s national air quality map is available online at www.airnow.gov
For more information contact Todd Russell, air quality ambient monitoring, (515) 281-8437, Todd.Russell@dnr.iowa.gov