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When Gretchen Alfonso, a 29-year-old mother of three, was growing up in Erie, Pennsylvania, fishing was part of the culture. The locals knew that the perch from Lake Erie was contaminated with toxic pollutants like mercury, but fish-fry dinners were a tradition no one wanted to give up. So on Friday nights, people ate perch. "The grown-ups joked about how you shouldn't eat too much of it," Alfonso remembers. Everyone ate the fish, including Alfonso.
Pregnant women are regularly warned now not to eat certain kinds of fish because mercury in swordfish and bass, for example, is a potent neurotoxin that can cross the placenta and affect fetal brain and nervous-system development. Worried, Alfonso had her mercury level tested when she was pregnant in 2010. Fortunately, her results were normal, but for the first time, she began to wonder about the actual source of the mercury that contaminates fish.
The answer is air pollution. No, fish don't breathe air the way humans do. But what goes up must come down. Coal-fired power plants and other industrial sources release mercury into the air that eventually settles to the floor of lakes, rivers, and oceans. Bacteria in the water convert it to methylmercury, which diffuses into single-celled algae and then moves up the food chain, making its way into fish. People eventually eat the big fish, the ones that have the highest concentrations of mercury.
After her second baby was born, Alfonso dug around online for information about mercury. She learned that nearly half of the nation's miles of rivers and acres of lakes (including all of the Great Lakes) and 79 percent of its coastal waters were under a water-contamination advisory -- 80 percent of them due to mercury. (In Lake Erie, PCBs are the greatest concern.) She also found the Moms Clean Air Force, an advocacy group that organizes parents to take action on air pollution (see "The Power of Mothers," on page 3). Alfonso's eyes had been opened to the enormity of the larger problem. "Suddenly, those old jokes about perch didn't seem so funny anymore," she says.
We think of air pollution as belching smokestacks and hazy highways, and it is. But as the fish advisories prove, it can also be invisible. Seen or unseen, air pollution -- which results from gas and particle contaminants emitted by vehicles, planes, and factories -- can cause irreparable harm when it gets into our children's lungs and bloodstream. Kids' exposure to airborne pollutants is higher because they usually spend more time outdoors than adults do and they breathe faster. And because of their size, when children eat, drink, or breathe they have a larger exposure per pound of body weight than adults. They also breathe through their mouth more, so they lose the benefit of the filtering system in their nostrils. Toxins that are inhaled are far more dangerous than those that are ingested because they pass directly into the lungs and then the bloodstream, undiluted.
I recently moved back to the U.S. after living in Hong Kong, a city cloaked in a haze of pollution much of the time. At my children's school, administrators closely watched the daily pollutant levels and regularly restricted outdoor time. The Hong Kong government's health standards are outdated, but even following their conservative recommendations, pollution kept kids with asthma and other respiratory problems inside more than half the days in 2011. My family breathed a collective sigh of relief when we returned to New York, where the air is measurably better.
At one point, the United States looked more like Hong Kong -- there were days when a huge haze hung over Los Angeles or Pittsburgh. Any improvement we've made is thanks to 1970's Clean Air Act. "The nature of air pollution has changed," says Parents advisor Philip J. Landrigan, M.D., professor of pediatrics at the Mount Sinai School of Medicine, in New York City, and director of its Children's Environmental Health Center. "The truly gross pollution has gotten much better. But today we have a lot of fine-particle pollution, which is invisible but toxic to the lungs. So even though we've made progress, air pollution continues to be a threat to children's health."
Asthma tops a daunting list of physical problems associated with dirty air. What's more, researchers now think pollution doesn't just trigger asthma symptoms; it may cause the disease. Also on the list: allergies, sudden infant death syndrome, reduced birthweight, respiratory infections, and pediatric cancer. Unfortunately, even if we clean up our own skies, air pollution is truly a global issue. The fact is, the prevailing winds across the Pacific are currently blowing much of Asia's polluted air toward the United States.