Reduction of vehicle emissions of carbon — through more efficient vehicles, mass transit, car pooling, cycling, etc. — also reduces all other forms of air pollution associated with vehicle exhaust.
Federal air quality regulations don’t do enough to control ozone, fine particulates (especially from diesel engines, but also from cars) and other vehicle exhaust components. Federal air quality standards are applied by averaging samples over long periods of time. In fact, acute exposures to exhaust, from brief periods in intense traffic or long term residence near freeways, have been shown to have measurable negative health effects. See generally, The Harmful Effects of Vehicle Exhaust.
One of the striking features of the emerging understandings of the continuing problem of air pollution is how local the problem is.
- Real time measurements show that bicyclists riding in traffic are exposed to high levels of ultrafine particulates and post-exposure measurements confirm that they suffer oxidative damage to their DNA much greater than bicyclists exercising indoors (who experience no unusual elevation of damage). Oxidative damage to DNA is potentially carcinogenic.
- Long-term air pollution exposure and living close to busy roads are associated with COPD in women chronic obstructive pulmonary disease. COPD stands for chronic obstructive pulmonary disease.
- Particulates from freeway vehicles do penetrate indoors, although their concentrations may be reduced to varying degrees. See abstract on penetration of ultrafine particles.
- The California Air Resources Board has recommended against siting of schools, residences, medical facilities, etc. within 500 feet of a freeway and has defined distance standards for other places where vehicle exhausts are concentrated, like rail yards, ports, and distribution centers.
Any effort to reduce vehicle combustion — to the end of reducing carbon emissions — will contribute to reduction of local air pollution. The reverse is not necessarily true — we can improve local health greatly by reducing particulate emissions by vehicles without necessarily improving their mileage per gallon or reducing travel.