Why Coal Plants Are So Sickening
Today, acute pollution crises are rare in the developed world, but coal-burning still exerts an insidious effect on health. The worst impact is on children. Burning coal releases mercury, nitrogen oxides, sulfur oxides, and fine particulate matter, among other nasty emissions. Mercury from power plants settles in water, where bacteria transform it to an organic form called methylmercury. It contaminates fish and bioaccumulates through the food chain, so larger predators are especially contaminated. That’s bad news for lovers of swordfish and spicy tuna, especially for women who plan to have children. During pregnancy, methylmercury crosses the placenta and gets into the developing brains of fetuses. Research shows that this exposure can cause neurological and developmental deficits down the road. One pivotal study, conducted in the Faroe Islands, looked at methylmercury levels in mothers’ hair samples and babies’ umbilical-cord blood at birth. Seven years later, the children who had had higher levels tended to show deficits related to
language, attention, and memory on a battery of neuropsychological tests. Other large studies of methylmercury exposure during gestation, conducted in
New Zealand and the Seychelles, have come to similarly worrisome conclusions. Coal is not kind to children’s brains.
What about children’s lungs? Nitrogen oxides, which are emitted from smokestacks, are known to irritate the respiratory tract. They also react with other pollutants to produce ozone, which is a key component of smog. And hazy, smoggy, ozone-filled air is just terrible for kids with asthma. In one key study, researchers looked at emergency visits by low-income children in Atlanta during the summer of 1990. They correlated the dates of these visits, which were for asthma or reactive airway disease, with data on local ozone levels. Following the six highest ozone days, the average number of emergency visits spiked
37 percent compared to other days. Lots of other research confirms that
ozone can make asthma worse. (Some evidence links it to the development of asthma, too, though that is
not as well-established.) Then there is particulate matter, especially the tiny particles with a diameter of less than 2.5 micrometers, which studies show can trigger asthma attacks. Children are especially vulnerable because they tend to breathe through their mouths, which means less filtering of pollutants by nose hair; they tend to hang out more outside, where levels of these pollutants are usually higher; and they run around a lot, which means they take in more nasty stuff and inhale it deep into their lungs.
But it isn’t just children who are vulnerable. In adults, higher levels of small particulates are associated with an increase in heart attacks, exacerbations of congestive heart failure, and the triggering of cardiac arrhythmias. An excellent rundown of the research appears in Alan Lockwood’s
The Silent Epidemic: Coal and the Hidden Threat to Health. Lockwood cites, for example, a finding from the Women’s Health Initiative looking at more than 60,000 older women.
That work found that each increase of 10 micrograms in the concentration of very fine particles per meter cubed of air upped women’s chances of a “cardiovascular event” by 24 percent. And it increased the chances of death from such an event by 76 percent. Lockwood’s book paints a similarly bleak picture of air pollution and lung cancer.
