WINDSOR HEIGHTS – Ozone levels near Environmental Protection Agency (EPA) health standards are expected in Clinton and Scott Counties during afternoon today. Cooler temperatures are expected to bring ozone levels back to normal on Sunday.
The Department of Natural Resources recommends that Iowans living in this area with respiratory or heart disease, the elderly, and children limit prolonged outdoor exertion until air quality conditions improve.
The EPA’s 8-hour health threshold for ozone is 75 parts per billion.
As of noon today, one-hour ozone levels were in the 60s in Clinton and Scott Counties and expected to rise to levels near the EPA threshold over the afternoon. Yesterday, an ozone monitor in Clinton recorded an eight-hour average ozone level of 76 ppb.
Ozone levels across Iowa, Illinois, and Missouri were elevated yesterday afternoon and are expected to remain so today, as light winds, clear skies and high temperatures across the region favor the formation of photochemical smog. In these conditions, volatile organic compounds react with nitrogen oxide resulting in an increase in ozone. Volatile organic compounds are emitted from the evaporation of consumer and industrial solvents, such as the evaporation from gas tanks in vehicles or mowers. Nitrogen oxides are created by combustion, and are contained in the exhaust from vehicles and coal-fired boilers.
EPA’s national air quality map is available online at www.airnow.gov