StoryImage( ‘/Images/Story//img-ZYNDN97qeM.jpg’, ‘Photos courtesy of U.S. Environmental Protection Agency’, ‘Part of Rocky Mountain National Park is seen on a clear day (left) and on a day of significant ozone pollution (right). Trends in deteriorating air quality and adverse impacts of fossil fuels on human health are global.’);
StoryImage( ‘/Images/Story//img-stGs9IpaQg.jpg’, ”, ”);
Recent columns addressed the explosion of garlic mustard apparently nurtured by atmospheric changes and the associated destruction of spring flora. Similar ecological changes are occurring throughout the world as fossil fuel dependent economies spread.
Fossil fuel dependency also adversely affects human health. It is clear that we are experiencing an increase in respiratory problems, hospitalizations and premature death partially caused by air pollution. This is especially difficult for children and elderly people with pre-existing cardiac or respiratory illnesses.
Trends in deteriorating air quality and adverse impacts on human health are global. In Mexico City, we watched mountains disappear as early morning traffic increased, smog levels rose and the air was filled with a brown haze.
Mexico Citys more than 3 million vehicles account for 75 percent of its air pollution. In 1999, ozone levels were unacceptable on 300 days. However, that represented an improvement since ozone levels were high enough to limit auto traffic on only five days. In the early 1990s, such emergency declarations occurred on 177 days.
In Peru, people who sweep sidewalks wear face masks to limit their inhalation of dust, smog and diesel fumes. Police in Thailand wear similar masks and can only serve as traffic police for a few years before succumbing to respiratory problems. Similar conditions were common in Japan in the 1970s and are likely to be more common in China as their auto dependency increases.
An average Americans most polluting common daily activity is driving a private car. The combustion process emits hydrocarbons and unburned or partially burned fuel, which combines with nitrogen oxides to produce ozone, a major component of smog. Ozone irritates eyes, damages lungs and aggravates respiratory problems.
Carbon monoxide is another byproduct of incomplete combustion. When inhaled, it enters the bloodstream through the lungs and can produce headaches, nausea and decreased mental alertness. It is particularly dangerous for people with heart disease.
As cars have become less polluting, more people drive more miles, offsetting the gains from improved pollution controls. An average driver does not notice transportation dust from wearing road surfaces, brake linings and tires. We never thought much about tire wear until one of us developed an allergy to latex. A literature search suggested increased latex allergies may be linked to its increasing atmospheric levels caused by wearing out millions of tires annually.
Another potential surprise is related to the increased use of catalytic converters to lessen auto emissions. As they wear, converters release fine particles of heavy metals like platinum, palladium and rhodium, whose impacts on human health and the environment remain largely unknown.
The recent reduction of allowable limits of ozone from 120 ppb to 85 ppb is a step in the right direction, but it is far from adequate. It is time for fleet averages for cars to be raised to 45 miles per gallon and 35 miles per gallon for light trucks. It would improve the quality of our air and the health of our citizens as well as lessening our oil dependence and its attendant costs.