Project at a Glance
Title: Development and implementation of exposure assessment procedures for toxic air pollutants in several Los Angeles County (California) communities
Principal Investigator / Author(s): Pellizzari, E.D.
Contractor: Research Triangle Institute
Contract Number: a5-174-33
Research Program Area: Health & Exposure
Topic Areas: Indoor Air Quality, Toxic Air Contaminants
The Toxic Exposure Assessment Methodology (TEAM) study was conceived in 1979 to: 1) develop methods to measure personal total exposure (air, water and food) and resulting body burden of toxic and carcinogenic chemicals and 2) apply these methods within a probability-based sampling strategy to estimate exposures and body burdens of urban populations in several U.S. cities. A pilot study, conducted in July and December 1980, tested preliminary sampling and analysis protocols, for chemicals potentially present in air, water, food, house dust, blood, breath urine and human hair. Volatile and semi-volatile organic compounds, metals and PAHs were included as target species in the pilot phase. The results of this study conducted, on nine participants from New Jersey and three from North Carolina, indicated that the overall goals of the TEAM program could be met by monitoring only the volatile organic compounds in personal and ambient air, exhaled breath and drinking water.
The main TEAM study monitored exposures of approximately 600 people in Bayonne and Elizabeth, New Jersey (1981, 1982, 1983, 1987); Greensboro, North Carolina (1982): Devil's Lake, North Dakota (1982): Antioch and Pittsburgh, California (1984) and Los Angeles County, California (1984, 1987). Target chemicals (20) were selected on the basis of their toxicity/carcinogenicity, production volume, detection in previous studies and facility to collection on Tenax monitors. In addition to outdoor stationary air samplers, each participant carried a small battery-powered, personal air sampler for two consecutive (overnight and daytime) sampling periods. A single breath sample was collected from each participant at the end of the 24 hours. Two drinking water samplers were also collected from each participant. The 600 participants selected and monitored represented a total population of 700,000 residents.
In addition to the pilot and main TEAM studies, four special studies were undertaken: 1) a nursing mothers study conducted on 17 nursing mothers in Bayonne and Elizabeth, NJ to assess accumulation of the target chemicals in mother's milk and the relationship between exposure and body burden; 2) a dry cleaners study to investigate employee exposure to tetrachloroethylene, l.l.l-trichloroethane, and aromatic solvents; 3) a swimming pool study to monitor lifeguards for elevated chloroform exposure; 4) an indoor air study to measure volatile organics, pesticides, PCBs, respirable particulates, metals and formaldehyde in four public buildings. The significant findings of the TEAM study may be summarized as follows:
1. Personal exposures to most of the target chemicals can be effectively measured using Tenax monitors.
2. Exhaled breath provides a sensitive and non-invasive means to determine the target compounds in blood.
3. Mean personal air levels of the eleven prevalent target chemicals were almost always greater than mean outdoor concentrations, suggesting significant indoor air exposures at home and at work.
4. Elevated indoor air levels of pollutantsmay be attributed to consumer products, building materials and personal activities.
5. For nearly all chemicals, breath levels showed significant correlation with personal air concentrations but not with outdoor air levels.
6. Specific exposure sources included:
a. Smoking (benzene, xylenes, ethylbenzene, styrene in breath)
b. Passive smoking (same chemicals in indoor air)
c. Visiting dry cleaners (tetrachloroethylene in breath)
d. Auto exhaust (benzene in breath)
e. Various occupations, including: chemicals, plastics, wood processing, scientific laboratories, garage or repair work, metal work, printing (mostly aromatic chemicals in daytime personal air).
7. The overall impact of these sources far surpassed that of residential proximity to chemical plants, petroleum refineries, petrochemical plants, drycleaners and service stations on personal exposure.
8. With the exception of the trihalomethanes, greater than 99% of the exposure was attributed to air. Nearly all of the exposure to the three brominated trihalomethanes and more than half of most exposure to chloroform was attributed to drinking water.
For questions regarding research reports, contact: Heather Choi at (916) 322-3893
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