DES MOINES – High temperatures and clear skies on Friday and Saturday are likely to lead to elevated ozone levels.  The Department of Natural Resources recommends that Iowans with respiratory or heart disease, the elderly, and children limit prolonged outdoor exertion during the afternoon and evening on Friday and Saturday.

Hot and sunny conditions are anticipated across the region, which 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.

Iowans can keep track of evolving air quality conditions by checking the U.S. Environmental Protection Agency’s national air quality map at www.airnow.gov.