By Sarah Ahmed - October 23, 2013
by Elly Blue
This is an excerpt from “Bikenomics: How Bicycling Can Save the Economy,” by Elly Blue (Microcosm Publishing, December 1, 2013, bikenomics.com).
Car exhaust is no laughing matter. Nearly half of residents in major urban areas in North America live close enough to highways and other large roads to experience serious problems as a result. Exposure to car emissions worsens and may cause asthma and other lung conditions, including lung cancer. There is evidence to suggest that it leads to hardening of the arteries and thence to heart disease. One study has found an increased risk of heart attacks while in traffic, either while driving or using public transportation. Breathing car exhaust may increase the risk of developing diabetes; it is certain, however, that people who have diabetes suffer disproportionately from the effects of air pollution.
The worst effects of breathing polluted air are experienced where it is densest: in traffic. Spending time on and near highways, freeways, and other busy roads is terrible for your health. How near is a question that is still being studied, but researchers believe that the effects are worst within either a fifth or a third of a mile. People in cars or buses are exposed to considerably more air pollution, perhaps because of, rather than despite, being in a closed space. People walking and bicycling on or next to roads breathe more air, but inhale somewhat less pollution; and cyclists have been found to have even less risk if they are on paths that are separated from the road.