By Dr. Ned Ketyer
Yesterday we reviewed new research studying the effects of air pollution exposure during pregnancy and the adverse health outcomes that can result — chromosomal damage, birth defects, complications of pregnancy — and impact children’s lives. But exposure after birth to components of air pollution, especially to invisible fine particulate matter (PM2.5), can have significant health consequences, too.
One recent study from Utah found that short-term exposure to elevated PM2.5 levels was associated with increased healthcare utilization — more doctors’ visits, more emergency department interactions, more hospitalizations — for acute lower respiratory infections (ALRI) in infants, children, and adults. Elevated numbers of infections with respiratory syncytial virus, which causes bronchiolitis in infants and small children, and influenza virus were seen in the group of 146,397 study participants — a population, suggests Nicholas Bakalar, that is not typically exposed to high levels of ambient PM2.5 pollution, which mostly comes from fossil fuel combustion in cars and trucks, power plants, and other pollution sources:
The scientists calculate that each short-term increase of 10 micrograms per cubic meter in PM2.5 is associated with a 15 to 23 percent increase in serious respiratory infections.
“There’s no reason to panic here,” said the lead author, Benjamin D. Horne, of Intermountain Medical Center Heart Institute. “When air pollution is high, avoid idling cars, stay distant from highways, stay indoors or go out in the early morning when pollution is usually lower. We don’t have to feel like we’re victims.”
But the problem is that when residents are advised by public health authorities to “stay indoors or go out early in the morning when pollution is usually lower” — in Utah! — they’ve already been victimized.
Researchers in Boston found, like our Pediatric Alliance colleague, Dr. Deborah Gentile, did in Pittsburgh, that children living close to sources of air pollution had higher risks of asthma. In the case of Boston, the source of pollution victimizing child respiratory health was urban traffic:
The study found that living close to a major road was linked to childhood asthma at all ages examined.
“Children living less than 100 meters from a major road had nearly three times the odds of current asthma – children who either experience asthma symptoms or use asthma medications daily – by ages seven to 10, compared with children living more than 400 meters away from a major road,” said Rice.
“Even in the Boston area, where pollution levels are relatively low and within Environmental Protection Agency standards, traffic-related pollutants appear to increase the risk of asthma in childhood,” said Rice, who is also an assistant professor at Harvard Medical School.
Teen health and behavior can also be affected by exposure to air pollution. Researchers at the University of Southern California found that older children and teenagers who live in areas of heavy air pollution like Los Angeles were more likely to behave badly (lie, steal, vandalize, use drugs) than those with less exposure. Nicole Wetsman describes the different pathways pollution might take to get to the brain:
Pollution has a few potential paths into the brain. Particles inhaled into the lungs can travel into the blood, and eventually circulate up to the brain. Particulate matter can also cause stress in the lungs, which could cause the production of inflammatory molecules that then head to the brain. Pollution might also hit the brain directly, when people inhale polluted air through their noses, which are connected to a part of the brain called the olfactory bulb. That path, Cory-Slechta says, means the particles skip past the protection usually offered by the blood-brain barrier.
Particulate matter is often accompanied by metals, organic matter, or other contaminants, all of which can wreak havoc on the brain—particularly during critical developmental windows. “It’s a physical response to pollution,” Younan says. “It’s damaging the brain.”
Robert Preidt points to a recent study showing that lungs and brains are not the only organs affected by breathing polluted air: The quality of the air she breathes might have an impact on a teen girl’s menstrual cycle, a new study suggests. U.S. researchers said that exposure to smoggy air could raise teen girls’ risk for irregular periods.
“While air pollution exposures have been linked to cardiovascular and pulmonary [lung] disease, this study suggests there may be other systems, such as the reproductive endocrine system, that are affected as well,” said lead researcher Dr. Shruthi Mahalingaiah. She’s assistant professor of obstetrics and gynecology at Boston University School of Medicine.
In the study, Mahalingaiah’s group looked at data from a major U.S. study on women’s health, and compared it to air quality data from the U.S. Environmental Protection Agency.
The investigators found that exposure to air pollution at ages 14 to 18 was associated with slightly higher chances of menstrual irregularity, and a longer time to achieve menstrual regularity in high school and early adulthood.
In the United States, children of color and those who are poor appear to be at highest risk for being exposed to elevated levels of air pollution and experiencing the resulting negative health impacts. Oliver Milman brings us full-circle, back home to Pittsburgh with the results of a recent study:
Schoolchildren across the US are plagued by air pollution that’s linked to multiple brain-related problems, with black, Hispanic and low-income students most likely to be exposed to a fug of harmful toxins at school, scientists and educators have warned.
The warnings come after widespread exposure to toxins was found in new research using EPA and census data to map out the air pollution exposure for nearly 90,000 public schools across the US.
“This could well be impacting an entire generation of our society,” said Dr Sara Grineski, an academic who has authored the first national study, published in the journal Environmental Research, on air pollution and schools.
The five worst polluted areas include New York, Chicago and Pittsburgh, as well as Jersey City and Camden in New Jersey. One teacher in Camden told the Guardian that heavy industry was “destroying our children”.
There must be a better way.