Traffic exhaust pollutants include compounds such as carbon monoxide, nitrogen oxides, particulates (fine dust and soot), and toxic air pollutants such as benzene. Ozone also results indirectly from traffic, as nitrogen oxides combine with volatile organic compounds in the presence of sunlight. Traffic exhaust pollutants are a major source of air pollution in California, especially in urban areas, and are a major source of greenhouse gas emissions. Vehicles run on conventional or diesel engines. Although diesel engines are more efficient, they emit more fine particles than convential engines, and according to the California Air Resources Board, diesel exhaust is responsible for 70 percent of the cancer risk that the average Californian faces from breathing toxic air pollutants (see http://www.oehha.ca.gov/public_info/facts/dieselfacts.html). Potential health effects from being exposed to traffic-exhaust pollutants include repiratory illnesses (including asthma), cardiovascular disease, adverse reproductive outcomes, cancer, and shortening of the life span.
EHIB is engaged in a number of activities examining how the health of Californians are affected by traffic-exhaust pollutants. EHIB has completed studies investigating whether children who live near busy roads are at increased risk of asthma exacerbations and leukemia; and have been engaged in developing statistical models of traffic pollutants which will allow us to predict who is being exposed and at what levels. EHIB has also examined issues of environmental justice in terms of what types of populations live near busy roads.
- Examining associations between childhood asthma and traffic flow using a geographic information system.
- Hierarchical modeling of spatio-temporally misaligned data: Relating traffic density to pediatric asthma hospitalizations.