Corporate Banner
Satellite Banner
Environmental Analysis
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Early-life Air Pollution Linked with Childhood Asthma in Minorities, in Study

Published: Thursday, June 20, 2013
Last Updated: Thursday, June 20, 2013
Bookmark and Share
Research by UCSF team indicates that traffic-related pollution might be a cause.

A research team led by UC San Francisco scientists has found that exposure in infancy to nitrogen dioxide (NO2), a component of motor vehicle air pollution, is strongly linked with later development of childhood asthma among African Americans and Latinos.

The researchers said their findings indicate that air pollution might, in fact, be a cause of the disease, and they called for a tightening of U.S government standards for annual exposure to NO2.

The study is reported online currently in the American Journal of Respiratory and Critical Care Medicine ahead of print publication.

In the study, the largest to date of air pollution exposure and asthma risk in minority children in the United States, the team found that for every five parts per billion increase in NO2 exposure during the first year of life, there was a 17 percent increase in the risk of developing asthma later in life.

The study involved 3,343 Latino and 977 African American participants.

“Many previous studies have shown an obvious link between traffic-related pollution and childhood asthma, but this has never been thoroughly looked at before in an all-minority population,” said lead author Katherine K. Nishimura, MPH, a graduate student in the laboratory of senior author Esteban G. Burchard, MD, MPH, a UCSF professor of bioengineering and therapeutic sciences and medicine and director of the UCSF Center for Genes, Environment & Health.

Minorities tend to live in areas of higher air pollution and have a higher risk of developing asthma, the researchers said.

What made the current study different from previous research, said Nishimura, was that the scientists looked retrospectively at the study participants’ exposure to air pollution in early childhood, before they developed asthma. Children who developed asthma before this exposure period were excluded.

“Any participant with asthma in this study was exposed to air pollution in infancy, before they developed the disease, which is a step in the right direction in inferring causality,” said Nishimura.

“This work adds to the growing body of evidence that traffic-related pollutants may be causally related to childhood asthma,” said Burchard.

National Standard for NO2 is 'Too Lax'

Study co-author John R. Balmes, MD, of UCSF and UC Berkeley, pointed out that a previous study of children living in Southern California showed that living and attending school close to major roadways was associated with an increased risk of new-onset asthma. “Together with our findings, this makes for strong evidence that reducing children’s exposure to traffic emissions can prevent some cases of asthma,” said Balmes.

One immediate implication of the study, said Burchard, is that the national standard for NO2 set by the Environmental Protection Agency is “too lax by far.” He noted that the current EPA annual standard is 53 parts per billion (ppb), while the study subjects were exposed, on average, to 19 ppb during the first year of life.

“Children growing up in Southern California have been shown to have reduced growth of lung function when annual NO2 levels are below the current national annual standard,” added Balmes.

The participants, who were between the ages of 8 and 21 and had no other lung diseases or chronic illnesses, were recruited from study centers in Chicago, New York City, Houston, the San Francisco Bay Area and Puerto Rico. To adjust for instances when study participants moved residences, air pollution exposure for all subjects was assessed by using the residential histories from birth through time of recruitment. The researchers based their air pollution exposure estimates on EPA annual measurements.

“The geographic diversity of the study population strengthens the results, because the effects we see are consistent across a wide range of urban environments and conditions,” said Nishimura.

Possible Explanations for How Air Pollution Causes Asthma

While the study was not designed to investigate how air pollution might cause childhood asthma, said Nishimura, the investigators are looking at two possible causes.

The first is that NO2 can interact with a number of other pollutants to create reactive oxygen species – chemically reactive molecules containing oxygen – which can, in turn, damage developing lungs. Immune systems that develop under such conditions, she said, could be “trained” to respond to pollutants as triggers that could later induce asthma.

Another possible explanation, said Nishimura, is that pollutants can potentially cause a genetic predisposition to asthma by altering methylation patterns in DNA. Methylation is a chemical change that alters gene expression without affecting the underlying structure of the DNA itself.

“It has been shown that changes in methylation, which can be affected by pollution, tobacco smoke and even stress, can be inherited across multiple generations,” said Burchard. “Our group is currently investigating methylation as the possible outcome of exposures to a number of pollutants.”

Burchard cautioned that air pollution is “not the entire story,” noting that despite its low air pollution levels, Puerto Rico has the highest asthma prevalence and morbidity in the United States. “This is intriguing, and leaves us more work to do,” he said.


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More than 3,800+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.


Scientific News
Low-level Arsenic Exposure Before Birth Associated with Early Puberty in Female Mice
Study examine whether low-dose arsenic exposure could have similar health outcomes in humans.
Intensity of Desert Storms May Affect Ocean Phytoplankton
MIT study finds phytoplankton are extremely sensitive to changing levels of desert dust.
Determination of Phosphate in Soil Extracts in the Field: A Green Chemistry Enzymatic Method
New method for phosphate determination which can be carried out in the field to obtain results on the spot.
Open-Source Photometric System for Enzymatic Nitrate Quantification
New method proposed for developing a cheaper, more accessible open-source water testing platform capable of performing Nitrate Reductase Nitrate-Nitrogen Analysis.
Toxic Algae is a Threat to Our Water
A report concludes that blooms of toxic cyanobacteria, or blue-green algae, are a poorly monitored and underappreciated risk to recreational and drinking water quality in the U.S., and may increasingly pose a global health threat.
Significant Part of Greenhouse Gas Emissions Comes From River and Sea Organisms
Running streams are key sources of the greenhouse gas carbon dioxide, but why is it so?
Better Estimates of Worldwide Mercury Pollution
New findings show Asia produces twice as much mercury emissions as previously thought.
Real-Time Data for Cancer Therapy
Biochemical sensor implanted at initial biopsy could allow doctors to better monitor and adjust cancer treatments.
New Biosensors for Managing Microbial ‘Workers’
Researchers at Harvard’s Wyss Institute have unveiled new biosensors that enable scientists to more effectively control and 'communicate with' engineered bacteria.
Playing 'Tag' with Pollution lets Scientists See Who's It
Using a climate model that can tag sources of soot from different global regions and can track where it lands on the Tibetan Plateau, researchers have determined which areas around the plateau contribute the most soot — and where.
Scroll Up
Scroll Down
SELECTBIO

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!