A child's lungs begin forming in utero and continue to grow well into adulthood. Like a seed that needs sunlight and water to flower, a developing baby's lungs need clean air to grow to their full capacity. "If they start breathing air that's polluted, the air sacs could stop growing," explains Kari Nadeau, M.D., Ph.D., an allergist and immunology specialist at Stanford University School of Medicine. In fact, a study of 1,900 Swedish children revealed a troubling finding: Exposure to air pollution from traffic in the first year of life was associated with a significant decrease in lung function among children up to age 8.
Asthma, an inflammation of the airways that results in less airflow to the lungs, affects about 7 million American children. It affects their parents too. "One of the scariest things is rushing your child to the emergency room because he's struggling to breathe," says Senator Kirsten Gillibrand (D-NY), whose 9-year-old son, Theodore, has asthma. The disease is clearly worse in children who live near highways. "There is overwhelming evidence now that any type of air pollution, especially ozone and diesel-exhaust particles, can make asthma worse," says Dr. Nadeau. She's among the researchers whose work has shown that children's asthma can be linked to air pollution because the toxic exposure alters the function of cells that regulate their immune system.
The problem can start before a child is born. A recent study at Seattle Children's Research Institute found that even low traffic-related pollution led to increased numbers of babies who were small for their gestational age. Christina Schwindt, M.D., an allergist and immunologist in Mission Viejo, California, is in the midst of a two-year retrospective study looking at pregnant women's exposure to pollution in the home, at work, and in their car, and the possible risk of their babies developing asthma. "We know there's a genetic basis to the increase in asthma rates, but the increase has been too quick to be due to genetics alone. We know it's genetics interacting with the environment," she says.
Air pollution may also affect the development of children's nervous and endocrine systems. Dr. Nadeau worries that when babies and young children inhale toxins, it could lead to cancer and other diseases later in life. Researchers haven't yet connected all of those dots -- and it isn't easy to do so given the number of variables involved -- but studies are underway looking at links between air pollution and obesity, autoimmune diseases, and cancer. Two recent studies, from UCLA and the University of Southern California, also found an association between prenatal exposure to traffic pollution and autism.
Policing the Air
The Clean Air Act required the Environmental Protection Agency (EPA) to establish and monitor safe air concentrations for six of the most common pollutants: ground-level ozone, particulate matter, sulfur dioxide, lead, carbon monoxide, and nitrogen dioxide. Between 1990 and 2010, levels of all six pollutants dropped and America's air quality improved as much as 80 percent depending on the pollutant being measured. Levels of lead, which can lower a child's IQ and damage the nervous system, fell the furthest -- 83 percent in the last 20 years -- after it was removed from gasoline.
The EPA is proud of its accomplishments. "In 2010 alone, the reductions we've already achieved under the Clean Air Act prevented 130,000 heart attacks, 86,000 hospital visits, 3.2 million lost school days, and 1.7 million asthma attacks or episodes," says Lisa Jackson, former EPA Administrator.
But a startling 42 percent of Americans -- which works out to nearly 132 million people -- live in counties where the levels of ground-level ozone and particulate matter make the air harmful to breathe, according to the American Lung Association. Ozone has been linked with premature deaths, and particulate matter in its smallest form (which is soot, also known as "fine-particle pollution") is what worries asthma experts the most.
The sources of air pollution vary across the country, since there are more coal-fired power plants in the East and the Midwest, for instance, and more cars in the West. Particulate matter can come straight out of a car's tailpipe, an industrial smokestack, or a woodstove chimney, or it can form in the atmosphere from chemical reactions of sulfur dioxide and nitrogen oxides. Ground-level ozone is created when nitrogen oxide and volatile organic compounds "cook" in the sunlight. (That's why levels are higher in warm summer months.) Whatever the source, particulate matter and ozone are harmful to health -- and children are among the groups considered at risk from exposure to these pollutants.
The most effective way to continue reducing pollutants is to stop them at the source. But that requires determination and political will. In December 2011, the EPA announced that power plants have to adhere to a new, separate set of standards for mercury and air toxics, but opponents are battling the new regulations in court. Even if those challenges aren't successful, the plants have until April 2015 to comply. Meanwhile, the EPA's tighter standards for fine-particulate matter, announced in December 2012, are also being fought; some members of Congress want to ease up the restrictions in the Clean Air Act because they believe the current regulations cost jobs. Warns Senator Gillibrand: "If the attacks on the Act were successful, polluters would be protected while the public health would be put at risk." But even if the opposition fails, states don't have to implement their plans to meet these new standards until 2020 (and can request a possible extension to 2025).
During my time in Hong Kong, the pollution was so pervasive that it was hard to know how I could protect my family. I could keep my windows shut, but most of the sources of pollution seemed far beyond my control. Here in the United States, I can make my opinions heard. That's what Gretchen Alfonso did. Now, she organizes events for Moms Clean Air Force as a national field manager, educating moms and kids and getting them to meet with politicians. As she puts it, "It's so important for us to realize we have a voice."