Special Reports

A Special Report of the Institute's Diesel Epidemiology Working Group. The Diesel Epidemiology Working Group was formed in the fall of 2000 to (1) review reports from 6 diesel feasibility studies funded by HEI to provide information on potential study populations and on exposure assessment methods; and (2) consider the results of the feasibility studies and other ongoing research in order to develop a new research agenda to seek better information for quantitative risk assessment of lung cancer and other chronic diseases that may result from exposure to diesel exhaust. The 6 feasibility studies described in this report were funded by HEI to provide insight about whether a new retrospective or prospective epidemiologic study could provide data to improve estimates of cancer risk from exposure to diesel exhaust, and about whether new methods of exposure analysis would allow us to reevaluate older epidemiologic studies.

A Special Report of the Institute's Diesel Epidemiology Expert Panel. Although epidemiologic data have been used generally to identify the hazards associated with exposure to diesel exhaust, questions remain as to whether the human data can be used to develop reliable estimates of the magnitude of any risk for lung cancer (that is, through quantitative risk assessment [QRA]), and whether new research efforts could provide any additional data needed. In response to such issues, the Health Effects Institute initiated the Diesel Epidemiology Project in 1998.

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.

A Special Report of the Institute's Diesel Working Group. Diesel engine emissions have the potential to cause adverse health effects, including cancer and other pulmonary and cardiovascular diseases. However, it is difficult to distinguish the potential health risks attributable to exposure to diesel exhaust from those attributable to other air pollutants. For over a decade, HEI has supported a broad-based research program to evaluate the health risks of diesel emissions, including investigations of carcinogenesis, modeling studies, and emissions characterization. The purpose of this Special Report is to examine what is known, not known, and still uncertain about the health risks of exposure to diesel emissions.