Ambient monitoring of acid aerosols in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. Measurements made in Kingston, TN, and Steubenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 times during summer months. Periods of elevated acidic aerosols occur less frequently in winter months. The H+ determined during episodic conditions in southern Ontario indicates that respiratory tract deposition can exceed the effects level reported in clinical studies. Observed 12-hr H+ concentrations exceeded 550 nmole/m3 (approximately 27 μg/m3 H2SO4). The maximum estimated 1-hr concentration exceeded 1500 nmole/m3 for H+ ions. At 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 μg/m3.
CITATION STYLE
Spengler, J. D., Keeler, G. J., Koutrakis, P., Ryan, P. B., Raizenne, M., & Franklin, C. A. (1989). Exposures to acidic aerosols. Environmental Health Perspectives, 79, 43–51. https://doi.org/10.1289/ehp.897943
Mendeley helps you to discover research relevant for your work.