Workshop on the health effects of HCl in ambient air

This article presents a summary of the proceedings of the Workshop on the Health Effects of HCl in Ambient Air, held in Detroit, Michigan, on October 15, 1990. Participants addressed three topic areas: sources, levels, and chemistry of HCl in ambient air; toxicity of atmospheric HCI to humans and animals; and the need for future research on toxicity and exposure. Consensus conclusions related to each of these topic areas, arising form the deliberations of the workshop participants, are presented. These include: (1) atmospheric HCl will most commonly exist in the gaseous form; (2) long-range transport of HCl is probably of limited importance; (3) ambient HCI levels are in the low parts per billion range; (4) irritation of the upper airways appears to be the most sensitive indicator of exposure; (5) such effects are likely to occur only at exposure levels much greater than those measured in ambient air; and (6) future health research should focus on occupationally exposed populations and potentially sensitive subgroups, e.g., asthmatics.