Human biomonitoring after chemical incidents and during short-term maintenance work as a tool for exposure analysis and assessment

- Human biomonitoring (HBM) investigations were carried out for p-chloroaniline after a spill incident, and for benzene during regular turnarounds in three different chemical plants.
- p-Chloroaniline above background levels was detected mostly in urine samples of firefighters responding to the pyrolysis of pyraclostrobin, contaminated clothes being the most likely source of exposure.
- Three urinary biomarkers of benzene (ttMA, SPMA, unmetabolized benzene) were monitored throughout turnaround campaigns between 1993 and 2012.
- The correlations between the biomarkers of benzene in urine were significant: 25 μg SPMA/g creatinine correspond to 0.5 mg ttMA/g creatinine, and to 4.5 μg benzene/L, respectively.
- Human biomonitoring is a valuable tool for exposure analysis and assessment after incidental or short-term exposure to hazardous chemicals.

Human biomonitoring (HBM) is frequently used for the analysis and assessment of exposure to chemicals under routine working conditions. In recent years, HBM has also been applied to monitor the exposure of the general population, and of emergency responders in the aftermath of chemical incidents. Two examples of targeted HBM programs in the chemical industry are described and discussed in this paper: (1) analysis and assessment of the exposure of firefighters and chemical workers after the spill of p-chloroaniline from a burning chemical barrel, and (2) biomonitoring of maintenance workers potentially exposed to benzene during regular turnarounds. The results of these investigations underline that human biomonitoring contributes substantially to comprehensive exposure analyses, human health risk assessments and communication. In addition, regular HBM surveillance and feedback can assist in the continuous improvement of workplace safety measures and exposure control. In conclusion, data on accidental or short-term exposure to hazardous chemicals are an important source of information for the further development of limit and assessment values, the validation of biomarkers and of targeted HBM programs for both routine monitoring and disaster management.