Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers link childhood asthma to exposure to traffic-related pollution

20.09.2005


Univ. of Southern CA investigators show proximity to freeways poses respiratory risk



Living near a freeway may mean more than the annoying rumble of cars and trucks: For children, it brings an increased risk of asthma, according to researchers at the Keck School of Medicine of the University of Southern California.

Scientists studying air pollution levels in 10 Southern California cities found that the closer children live to a freeway, the greater their chance of having been diagnosed with asthma. They report their findings in the November issue of the journal Epidemiology.


Researchers also found that children who had higher levels of nitrogen dioxide, or NO2, in the air around their homes were more likely to have developed asthma. NO2 is a product of pollutants emitted from combustion engines, such as those in cars and trucks.

"These results suggest that tailpipe pollutants from freeway traffic are a significant risk factor for asthma," says lead author James Gauderman, Ph.D., associate professor of preventive medicine at the Keck School. "Considering the enormous costs associated with childhood asthma, today’s public policy toward regulating pollutants may merit some re-evaluation."

"These results have both scientific and public health implications," says David A. Schwartz, M.D., director of the National Institute of Environmental Health Sciences, the federal agency that funded the study. "They strengthen an emerging body of evidence that air pollution can cause asthma, and that exposure to outdoor levels of nitrogen dioxide and other traffic-related air pollutants may be a significant risk factor for this illness."

Researchers looked at the pollution-asthma link in 208 children who were part of the USC-led Children’s Health Study, the longest investigation ever into air pollution and kids’ health. The study has tracked the respiratory health of children in a group of Southern California cities since 1993.

The investigators placed air samplers outside the home of each student to measure NO2 levels. In addition, they determined the distance of each child’s home from local freeways, as well as how many vehicles traveled within 150 meters (about 164 yards) of the child’s home. Finally, they estimated traffic-related air pollution levels at each child’s home using models that take weather conditions, vehicle counts and other important factors into account.

In all, 31 children (15 percent) had asthma. Scientists found a link between asthma prevalence in the children and NO2 levels at their homes. For each increase of 5.7 parts per billion in average NO2-which represents a typical range from low to high pollution levels among Southern California cities-the risk of asthma increased by 83 percent. Risk of wheezing and current asthma medication use also rose as NO2 levels increased.

They also found that the closer the students lived to a freeway, the higher the NO2 levels outside their homes. NO2 levels also corresponded with traffic-related pollution estimates from the group’s statistical model.

It was not surprising, then, when they found that the closer the students lived to a freeway, the higher the students’ asthma prevalence. For every 1.2 kilometers (about three-quarters of a mile) the students lived closer to the freeway, asthma risk increased by 89 percent. For example, students who lived 400 meters from the freeway had an 89 percent higher risk of asthma than students living 1,600 meters away from the freeway.

Interestingly, the researchers saw that air pollution from freeway traffic influenced NO2 concentrations at homes more strongly than pollution from other types of roads. Traffic counts within 150 meters of homes (which primarily comprised traffic from smaller streets) were only weakly correlated with measured NO2.

In any community, a freeway is a major source of air pollution. "Cars and trucks traveling on freeways and other large roads may be a bigger source of pollutants that matter for asthma than traffic on smaller roads," Gauderman says. Scientists also find it difficult to get good data on traffic on smaller streets, which may make it harder to find associations between asthma and local traffic.

Gauderman cautions that researchers do not yet know that NO2 is to blame for the asthma. NO2 travels together with other airborne pollutants, such as particulate matter, so it may be a marker for other asthma-causing pollutants.

Study sites included the cities of Alpine, Atascadero, Lake Elsinore, Lancaster, Long Beach, Mira Loma, Riverside, San Dimas, Santa Maria and Upland.

Kathleen O’Neil | EurekAlert!
Further information:
http://www.usc.edu

More articles from Health and Medicine:

nachricht The end of pneumonia? New vaccine offers hope
23.10.2017 | University at Buffalo

nachricht Scientists track ovarian cancers to site of origin: Fallopian tubes
23.10.2017 | Johns Hopkins Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>