Assessment of Exposure to PACs in Asphalt Workers: Measurement of Urinary PACs and their Metabolites with an ELISA Kit

Abstract

An enzyme-linked immunosorbent assay (ELISA) kit made for determination of polycyclic aromatic compounds (PACs) in water was adapted for measuring PACs and their metabolites in urine. This method was then applied to a pilot asphalt worker PAC exposure study. Currently, liquid-liquid extraction with gas chromatography/isotope dilution high-resolution mass spectrometry (GC/HRMS) is the preferred method to determine urinary PAC metabolites. Although sensitive and specific, GC/HRMS is time consuming and costly.

The ELISA method had a range from 14–720 ng/ml 1-hydroxypyrene equivalents with a lower limit of detection (LOD) of 14 ng/ml urine. ELISA and GC/HRMS PAC metabolite measurements had a statistically significant correlation and the PAC ELISA results were indicative of potential asphalt exposure. PAC ELISA is promising as a more rapid and less costly routine method for determining worker exposure to PACs in asphalt emissions.

Key Words:

• asphalt
• biomonitoring
• ELISA
• PAC
• urine

ACKNOWLEDGMENTS

The authors thank Gary Fore and the National Asphalt Pavement Association and the State Asphalt Pavement Associations in the U.S. for providing funding for the project, and Tony Kriech and Linda Osborn of the Heritage Research Group for their coordination of the project. We also would like to thank Todd Dobbs, Kit Peregrine, Adam Redman, and Michael Brinton of Heritage Research Group, and John Clark and Michael Breitenstein of NIOSH for their field support. In addition, many thanks are given to the construction companies and workers whose sites were used for this study. The authors would also like to acknowledge Lovisa Romanoff, Zheng Li, Debra Trinidad, Erin Pittman, Sandra Lester, Kevin Hand, and Andreas Sjödin of the National Center for Environmental Health for providing GC/HRMS data for comparison. The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

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