Source apportionment of exposure to toxic volatile organic compounds using positive matrix factorization

Area of Science:

• Environmental Health
• Air Quality Science
• Toxicology

Background:

• Volatile organic compounds (VOCs) pose significant health risks.
• Understanding sources of toxic VOCs is crucial for exposure assessment.
• Previous studies have not fully differentiated personal exposure sources from outdoor concentrations.

Purpose of the Study:

• To identify and quantify sources of toxic volatile organic compounds (VOCs) in indoor and outdoor environments.
• To compare personal exposure to VOCs with ambient air concentrations.
• To investigate the relationship between participant activity patterns and estimated VOC source contributions.

Main Methods:

• Analysis of data from the Total Exposure Assessment Methodology (TEAM) studies and the California Indoor Exposure study.
• Application of positive matrix factorization (PMF) for source apportionment.
• Regression analysis to determine factor contributions to total exposure.

Main Results:

• Identified major sources of toxic VOCs for personal exposure in NJ and CA as aromatic sources (e.g., automobile exhaust, gasoline vapor, environmental tobacco smoke).
• Identified major sources of toxic VOCs for outdoor concentrations as automobile exhaust and gasoline vapors.
• Demonstrated the utility of comparing personal exposure and outdoor concentrations to understand exposure pathways.

Conclusions:

• Aromatic sources, including traffic and combustion-related emissions, are significant contributors to personal VOC exposure.
• Distinguishing between personal exposure sources and outdoor air quality is essential for accurate risk assessment.
• Activity-based analysis can help validate source apportionment findings for VOCs.