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EXPOSURES TO ACIDIC AEROSOLS
Citation:
Spengler, J., G. Keeler, P. Koutrakis, P. Ryan, M. Raizenne, AND C. Franklin. EXPOSURES TO ACIDIC AEROSOLS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-89/452.
Description:
Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 times during summer months. eriods of elevated acidic aerosols occur less frequently in winter months. he H+ determined during episodic conditions in southern Ontario indicates that respiratory tract deposition can exceed the effects level reported in clinical studies. bserved 12-hr H+ concentrations exceeded 550 nmole/m3 (approximately 27 ug/m3 H2SO4). he maximum estimated 1-hr concentration exceeded 1500 nmole/m3 for H+ ions. t these concentrations, an active child might receive more than 2000 nmole of H+ ion in 12 hr and in excess of 900 nmole during the hour when H2SO4 exceeded 50 ug/m3.