DO ODORS AT A WASTE MANAGEMENT FACILITY INDICATE A RISK TO HEALTH?

摘要

Odor control is a frequent issue at facilities that process municipal solid waste. Even waste-to-energy facilities, which are typically operated under 'negative pressure,' may be less than 100% effective at preventing the occasional release of odorous emissions. When odors travel off-property to nearby residents and businesses, the tangible exposure often elicits concerns about the specific chemicals responsible for the odor and the potential for the emissions to affect public health. However, because the gaseous compounds that may lead to objectionable off-site odors are generally different than those that might result in adverse health effects, conditions of odor and risk are not as closely linked as is sometimes assumed. While odors can be assessed through personal observations, the assessment of risk requires detailed knowledge of the composition of the emitted gases. The gas produced from the aerobic decay of municipal solid waste contains a different mix of chemicals that are not as well characterized than gas produced from the anaerobic decay of waste in a landfill (which has been analyzed by the U.S. EPA and others). Air samples were recently collected from the tipping floor of a waste-to-energy facility, analyzed for chemical composition, and evaluated for their potential to lead to off-site health risks. The composition of the gas was found to be similar to published data from other MSW handling facilities, and includes both basic hydrocarbons and some EPA-designated Hazardous Air Pollutants. Thirty-two different volatile organic compounds were detected. Ethanol was found to be the most prevalent compound, almost two orders of magnitude greater in concentration than other chemicals. Additional compounds identified in the gas samples include (in order of abundance) methyl ethyl ketone, acetone, sec-butanol, isopentane, acetaldehyde, butane, isopropyl alcohol, limonene, and 1-propanol. A case-specific atmospheric dispersion of the gases was modeled to predict off-site concentrations much smaller than levels known to cause adverse health effects. Based on odor characteristics of the gas, generically extrapolating the study to other settings suggests that short-term odorous conditions due to MSW management facilities (waste-to-energy facilities, transfer stations, etc.) do not typically correspond to significant long-term health risks.