Air Pollution

A Special Report of the Institute's Oxygenates Evaluation Committee. Oxygenated fuel (usually referred to as oxyfuel) was formulated to reduce carbon monoxide emissions and contains at least 2.7% oxygen by adding methyl tert-butyl ether (MTBE) or ethanol. Reformulated gasoline was formulated to help reduce ground-level ozone concentrations and contains at least 2% oxygen, has a reduced content of benzene and other aromatic compounds, and produces limited emissions of total air toxics. The introduction of fuels containing oxygenates elicited concerns from workers and the general public in some areas, including reports of unpleasant odors, headaches, or other symptoms attributed to the fuels, and questions about their effects on the cost of gasoline, the performance of engines, and fuel economy. This Special Report summarizes an intensive review of (1) the existing science of the health effects of oxygenates, (2) the risk evaluations done by the EPA in 1993 and 1994, and (3) in a qualitative way, the health effects of exposure to the new additives as they relate to the health effects of other pollutants whose levels in emissions change when fuels containing oxygenates are used.

In this pilot study, Dr. Mary Cook and colleagues at the Midwest Research Institute explored how exposure to methanol vapor might affect the human nervous system. Methanol could be used as an alternative fuel, but it may lead to increased levels of methanol and formaldehyde in the atmosphere. The investigators exposed 12 young male volunteers to either filtered air or methanol vapor and assessed their response using 20 commonly used tests of sensory, behavioral, and reasoning performance before, during, and after each exposure.

Report of the Institute's Health Research Committee. This report summarizes what emissions-related health problems, if any, would emerge if methanol were to become more widely used as an automotive fuel. Methanol-fueled vehicles emit both formaldehyde and methanol vapors. in 1985, HEI started a research program to investigate the potential health effects of aldehydes, including formaldehyde. Before proceeding with research on methanol vapors, the HEI Health Research Committee decided to undertake additional analysis.