Vehicular Exhaust and Air Pollution


Individual tailpipe emissions

Transport and fate in the environment

Measuring exposures

Prevention and control of exposure

Exposure Pathway

Risk assessment

Adverse effects

Harmful Effects

Dose Response

Absorption, Metabolism and Molecular Mechanisms of Action

Organ Sites of Toxicity


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Risk Assessment

What is the Hazard?

Ozone and Particulate Matter are both linked to non-cancerous effects such as decreased lung capacity and higher instances of asthma. In healthy subjects, eight to 45 years old, lung capacity decreased after one to three hours of exposure to certain levels of ambient ozone. This was noted at less than 0.16ppm for heavy exercise and less than .50 ppm when at rest.

Who is exposed?

Everyday exposure to ambient air is not a choice anyone gets to make. This makes the task of risk management tricky, this topic is discussed more thoroughly in the Prevention section. The management techniques range from gas efficiency, fleet expectations, public transportation and promotion of energy conservation. It is not feasible to manage everyone’s personal air supply. However for those who want to know their exposure, the Environmental Protection Agency monitors air quality. This is useful for the portions of the population that are more sensitive, such as children, asthmatics, active adults and the inexplicably sensitive.
Air Quality Index

Air quality changes with the temperature, winds, and road conditions. To protect oneself from the adverse health effects of air pollution it is important to know what the conditions are daily. The EPA has put together an Air Quality Index that is updated daily to inform the public of the risk of exposure. The Twin Cities information is available at: The AQI is based on four pollutants: ground-level ozone, sulfur dioxide, carbon monoxide and fine particles (PM2.5). However, they are not all monitored at each location. The pollutant with the highest value for that hour determines the AQI.
This table borrowed from the EPA’s website shows what the air quality descriptors are based on.

This table borrowed from the same site explains what the different colors mean.

For complete risk assessment and toxicological information on both PM 10 and Ozone: