May 23, 2001(San Francisco) -- Bad air may be silently stealing the lives of some of America's babies.
In a study conducted by the Institute for Social and Preventive Medicine University in Basel, Switzerland, and Harvard School of Public Health, researchers followed earlier data showing a correlation between air pollution and higher illness and death rates. They presented their findings this week at the American Thoracic Society annual meeting, an international conference of lung specialists.
The researchers reviewed the air quality and death rates for infants in eight large U.S. urban areas known for higher air pollution rates. The cities, representing a total population of 29 million, included New York, Chicago, Baltimore, Houston, Seattle, Philadelphia, Detroit, and Los Angeles. They were compared with other areas that had lower pollution rates.
For the study, the researchers measured the effects of the tiny, dirty solids and liquids circulating in the atmosphere, known as particulate matter, on infants up to 1-year-old. Specifically, they measured particulate matter called PM10, pollution that measures about 1/7th the size of a human hair. As a group, PM10 can be visible as smoke. But individually, they are so small that only a special microscope called an electron microscope can detect them.
"We were able to show in our assessment that 9% of [deaths] in infants aged 1-12 months may be due to PM10 air pollution," says Reinhard Kaiser, MD, MPH, the study's lead author. Considering that the overall infant mortality rate in the U.S. is about 250 per 100,000 live births, that means up to 25 of those deaths may be pollution related.
"We should be aware that not only elderly people ... are susceptible to air pollution effects, but we should also have our focus on infants," says Kaiser.
Ironically, the data used in the study covered 1995-1997, when infant mortality was decreasing and air pollution was relatively stable. The eight cities analyzed were all within federal clean air guidelines.
The researchers did determine that the mother's occupation, race, level of education, and marital status did not affect the study conclusions. However, it's not clear whether breastfeeding or the baby's position at the time of death altered the study's outcome.
For Kaiser, the message of this research is a call to social activism. Since it's impossible to protect your baby from breathing the air, he says it's important to advocate for tough, new clean air standards.