Characterization of Traffic Related Air Pollution in Elementary Schools and its
Impact on Asthmatic Children in El Paso, Texas
SUMMARY
Authors: Li, When-Whai, Sarnat, J.A., Rayson, A.U., Sarnat, S.E., Stock, T.H., Holguin, F., Greenwald, R., Olvera, H.A., Johnson, B.A.
National Urban Air Toxin Research Center Research Report, No. 20, 2011.
According to the U.S. Department of Transportation, 15 – 16 million passenger cars and 750,000
commercial vehicles cross the four ports of entry between El Paso and Ciudad Juárez each year. Trafficrelated pollutants concentrate within 100 meters of busy roads. Many schools are in these traffic zones.
This study investigated the air quality and children’s health in four schools in the El Paso Independent
School District. Three schools were located near Ascarate Park and close to Interstate 10, the Border
Highway, and the international bridges. One school is particularly close to an oil refinery. In 2009, a
different study found that two of these schools were among the most polluted schools in the nation. The
fourth school was located near the mountain in an area where there is healthier air flow and fewer sources
of pollution.
The purpose of the study was to identify pollutants that were in the air at the four schools and to find
information from indicators of the students’ health that might be related to air pollution. The results show
that the air pollution levels at the three schools near the pollution sources were higher than pollution
levels at the school in the clean air zone and often higher than recommended by the national air quality
standards. Children at these schools exhaled higher levels of nitric oxide than children at the school in the
clean air zone. Higher levels of nitric oxide is an indicator of inflammation in the lungs which is a
characteristic of asthma. All of the air quality monitors at the schools reported high levels of course
particulate matter (PM10-2.5).
Earlier studies have found that air pollution is related to respiratory problems for children who are exposed
to the pollution. Here is what those studies found.
 Increases in hourly ozone levels of 20 ppb were associated with an increase (5.1%) in respiratoryrelated emergency department visits for children in in Ciudad Juárez.
 Increases in particulate matter concentrations in the air was related to a 20% increase in asthmarelated emergency department visits for children in El Paso.
 Children in Ciudad Juárez had more lung inflammation (using the test of exhaled nitric oxide) when
there was a higher concentration of traffic-related nitrogen dioxide (NO2) in the air.
 Children who live along the Texas-Mexico border are hospitalized for asthma at a 36% higher rate
than children who do not live in this border area (Grineski, 2007).
This 2011 study found that the three schools in the high pollution zones:
 Had higher levels of volatile organic compounds – chemicals that result from burning gasoline in
cars, trucks, airplanes, etc.
 During the times when the studied measured higher levels of air pollutants, they found higher
airway inflammation and problems with lung function for children with asthma. The higher levels
of volatile organic compounds caused the strongest observed effects.
 Pollutants levels for indoor and outdoor air quality were often similar. Activities such as painting,
cooking with natural gas, art projects with glue, etc. increased the pollution levels indoors.