Workers' exposures and potential health risks to air toxics in a petrochemical complex assessed by improved methodology.

OBJECTIVE

This study was designed to comprehensively evaluate workers' potential health risks of exposure to 39 air toxics in the Ta-sher Petrochemical Complex.

METHODS

Open-Path Fourier Transform Infrared Spectroscopy (OP-FTIR) was used to measure concentrations of air toxics. We used the measured worksite concentrations between 1997 and 1999 at 11 companies in the petrochemical complex, employing 3,100 on-site workers. The 39 measured air toxics included 10 chemicals with acute reference exposure levels (RELa), 19 chemicals with chronic reference exposure levels (RELc), and 3 chemicals classified as Class 1 or 2A human carcinogens by the International Agency for Research on Cancer (IARC). We then used RELa to calculate the hazard index of acute health effects (HI ( A )) for workers in individual plants. We also calculated the hazard index of chronic health effects (HIc) and cancer risks for all workers in the entire petrochemical complex.

RESULTS

Workers in five companies had HI ( A ) greater than 1 because of toluene, benzene, methyl ethyl ketone, chloroform and isopropanol exposures. Workers in this petrochemical complex had HIc greater than 1 because of acrylonitrile, 1,3-butadiene, hydrogen cyanide, and n,n-dimethylformamide exposures. Risk of hematopoietic system cancer because of benzene and ethylene oxide exposure, and respiratory system cancer because of 1,3-butadiene exposure was estimated to be 3.1-6.1 x 10(-4) and 5.2-7.1 x 10(-4), respectively.

CONCLUSIONS

Our findings indicated that workers in the petrochemical complex might have excess cancer and noncancer risks due to acute or chronic exposures to air toxics from multiple emission sources.