ASTHMA
May 30, 2019

Cleaner Air Cuts Kids' Asthma

There was a stunning drop in childhood asthma rates in the communities around Los Angeles after air pollution regulations were put in place.

Air pollution is bad for people's health, but would it really make much of a difference if the air started to get cleaner? Well it did in Southern California. When air pollution dropped, so did childhood asthma.

The drop in nitrogen dioxide that occurred between 1993 and 2006 led to a 20 percent lower rate of new asthma cases, while the drop in fine particulate matter led to a 19 percent lower rate.

Asthma is the most common chronic children's disease, affecting about 14% of children worldwide.

Los Angeles and its surrounding areas have some of the country's dirtiest air, but with the help of emissions regulations it has been getting cleaner. Between 1993 and 2006, nitrogen dioxide levels in the Los Angeles area dropped by 22 percent. Fine particulate matter (PM2.5) dropped by 36 percent.

This makes Los Angeles an ideal place to study how cleaner air affects people's health. Often, researchers compare health information from two different areas, one more polluted than the other. In that type of study, any differences in health that are seen could be due to a host of geographic differences, from pollen count to poverty, not pollution. Here, looking at the same area during different time points, that problem is much less likely to crop up.

Levels of four different air pollutants in nine Southern California communities located near Los Angeles were taken in three different years, and then compared to the number of new asthma cases occurring in schoolchildren, starting in 1993. The nine communities studied were: Alpine, Lake Elsinore, Lake Gregory, Long Beach, Mira Loma, Riverside, San Dimas, Santa Maria and Upland. They are, on average, 60-70 miles from Los Angeles.

Two pollutants, nitrogen dioxide and fine particles (PM2.5) — mainly soot, smoke and dust — showed a significant correlation with new asthma cases did, while two other pollutants, ozone and PM10 (particles smaller than 10 micrometers), did not show a strong relationship with asthma cases.

The researchers estimate that the drop in nitrogen dioxide that occurred between 1993 and 2006 led to a 20 percent lower rate of new asthma cases, while the drop in fine particulate matter led to a 19 percent lower rate.

Communities that had larger drops in either nitrogen dioxide or PM2.5 had even greater declines in new asthma cases.

This is only a start. “While the findings show a clear benefit of lower air pollution levels, there must be continued efforts to reduce pollution in our region,” said researcher, Erika Garcia, a postdoctoral scholar at the Keck School of Medicine of the University of Southern California, in a statement. “We're not in a place where we can stop and say, ‘Hey, we've arrived’.”

The study makes clear that there are major health benefits to be gained by cleaning up the air. Benefits and healthcare savings that over time will far outweigh the costs of pollution control. As an editorial accompanying the study puts it, “This study also adds to the urgency of controlling ambient air pollution to benefit the next generation, and makes recent efforts to discredit and ignore evidence on health effects of ambient pollution even more concerning.”

Both the study and editorial appear in JAMA.

COMMENTS
NOTE: We regret that we cannot answer personal medical questions.
 
FOLLOW US
© 2016 interMDnet Corporation.