ARB's Community Health
This page last reviewed March 3, 2009
Air Monitoring Results
These data represent only a portion of the data that have been collected as part of this study. No conclusions about the overall meaning of these data should be made until all of the data have been processed and reviewed. Note: The air quality monitoring in Boyle Heights ended in May 2002.
In the initial phase of the study, monitoring of ambient air quality at Hollenbeck Middle School in the Boyle Heights community in Los Angeles began in February 2001 and ended in May 2002. We collected information on approximately 70 air pollutants. A table of air pollutants monitored is provided here. Criteria air pollutants were measured, some of which have health-based standards established; a standard is a level above which a pollutant is known to cause adverse health effects in humans. Toxic air pollutants were also measured. These pollutants are known or suspected to cause cancer or other serious illnesses. There is no safe level for toxic air pollutants. Monitoring of fewer air pollutants at Science Center and Soto Street was from March 2001 through October 2001. The data presented from Hollenbeck Middle School represent 16 months of monitoring for organic gases and particulate matter. The data for the pollutants are presented here.
Ambient levels of toxic air pollutants are routinely monitored at approximately twenty sites in the California air toxics monitoring network. Closest to Boyle Heights are North Long Beach, Los Angeles-North Main Street, and Burbank in Los Angeles County. In addition, criteria pollutants are routinely monitored at these 3 sites plus Hawthorne and Azusa.
Some air pollutants have health-based standards established. Information on these so-called criteria pollutants can be obtained below:
High Risk Toxic Air Pollutants
The Air Resources Board has identified the top 10 high risk toxic air pollutants and nine of them were measured in Boyle Heights at Hollenbeck Middle School. The top 10 high risk toxic air pollutants have potential health risks and cancer risks. Diesel particulate matter is a significant contributor to the potential cancer risk from air toxic pollutants in California, but diesel particulate matter was not measured at Hollenbeck Middle School because a method for directly measuring this pollutant is still being developed. However, the potential cancer risk is estimated for diesel particulate matter for the entire South Coast air basin. As shown in a graph illustrating the cancer risk due to individual pollutants, diesel particulate matter is the highest contributor to risk from air toxic pollutants. The next highest are benzene and 1,3-butadiene. Information on the nine measured high risk pollutants can be obtained below:
- Carbon Tetrachloride
- Hexavalent Chromium
- Methylene Chloride
Metals of interest
Due to nearby industrial sources, some metals were of particular interest in this study. Information on these metals are below:
Diesel Particulate Matter and Elemental Carbon
While diesel particulate matter contributes the most to overall risk from toxic air contaminants, it has proved very elusive to measure. We are exploring the options to estimate the impact of diesel particulate matter on public health in the community, including using elemental carbon as an estimator. However, there are technical difficulties to using elemental carbon to estimate diesel particulate matter. First, other sources of elemental carbon besides diesel particulate matter became more significant as emissions from the diesel fleet decreased as a result of improved diesel technologies. Second, there are many elemental carbon analysis methods that have evolved which give significantly different results when measuring the same particles in the air. In this study, the Air Resources Board used one elemental carbon analysis method, derived from the NIOSH method. Information on elemental carbon are presented below:
PAHs and Dioxins
Polycyclic aromatic hydrocarbons (PAHs) and dioxins have been identified as toxic air pollutants that may disproportionately impact infants and children. Benzo[a]pyrene is one of the six PAHs monitored in this study. Currently, there are no data available for dioxins in the Boyle Heights study area. Dioxin measurements began for the Boyle Heights area at the Science Center site in December 2001 and are expected to end around December 2003; the link below provides information on current activities. Information on PAHs and other compounds can be obtained below:
For all available data in Microsoft Excel format: