IMMUNOCHEMICAL DETECTION OF METABOLITES OF PARENT AND NITRO POLYCYCLIC AROMATIC-HYDROCARBONS IN URINE SAMPLES FROM PERSONS OCCUPATIONALLY EXPOSED TO DIESEL EXHAUST

An immunochemical assay was developed for the detection of metabolites excreted in urine as a result of occupational exposure to PAHs and nitro-PAHs. These metabolites were analyzed in a competitive ELISA, using an existing antibody (4D5) that has been developed against 6-aminobenzo[a]pyrene coupled to bovine serum albumine (B[a]P-BSA). A solid phase extraction (SPE) work-up procedure was optimized by dilution of pooled urine samples from rats exposed to 1-NP, in human urine. The application was validated by comparison of test results with urinary excreted 1-hydroxypyrene (1-OH-P) levels in a study among 28 railroad workers. Excretion of urinary metabolites was determined over two consecutive workdays. The 24 h average excretion of metabolites as determined in the immunoassay was not related to levels of particulate matter in the breathing zones of workers, nor to 1-OH-P excretion levels of the day of urine collection. However, it was significantly associated with the personal dust exposure of the day before (P < 0.0001), suggesting slow excretion of urinary metabolites. Smoking habits caused minor interference (P < 0.1).