Dermal exposure assessment to benzene and toluene using charcoal cloth pads

Abstract

Charcoal cloth pads have been used to assess volatile chemicals on the skin in a laboratory setting; however, they have not yet been applied to measure dermal exposure in occupational settings. This study aimed at evaluating whether charcoal pads can be used to assess dermal exposure to benzene and toluene in workers of a petrochemical plant. Inhalation and dermal exposure levels to benzene and toluene were assessed for workers of a petrochemical plant performing different jobs. Benzene uptake was assessed by determining S-phenylmercapturic acid in workers' urine samples. Dermal exposure levels on the charcoal pads were adjusted for ambient air levels of benzene and toluene by subtracting the amount of benzene or toluene measured in personal air from the amount of benzene or toluene measured on the charcoal pad. In general, measured external and internal exposure levels were low. The estimated contribution of the dermal route to internal benzene exposure levels was less than 0.06% for all jobs. Toluene personal air concentrations and benzene and toluene dermal exposure levels differed statistically significantly between job titles. For benzene, differences between jobs were larger for adjusted dermal exposures (maximum 17-fold, P ¼ 0.02) than for inhalation exposures (maximum two-fold, P ¼ 0.08). Also for toluene, although less clear, differences between jobs were larger for adjusted dermal exposures (maximum 23-fold, P ¼ 0.01) as compared to inhalation exposures (maximum 10-fold, P ¼ 0.01). Charcoal pads appeared to measure dermal exposures to benzene and toluene in addition to ambient air levels. Future studies applying charcoal cloth pads for the dermal exposure assessment at workplaces with higher dermal exposure to organic solvents may provide more insight into the biological relevance of dermal exposure levels measured by charcoal cloth pads. In addition, the design of the dermal sampler might be improved by configuring a dermal sampler, where part of the sampler is protected against direct contact and splashes, but still permeable for the gas phase. This design would most likely result in a better ability to correct for airborne concentrations at a given body location.

Human biological monitoring of suspected endocrine-disrupting compounds

“…Organic solvents have been measured in human alveolar air,177 blood,177178179 and urine 178179180181. Analysis of unmodified solvents in urine is regarded as specific biomarkers of exposure and correlate to occupational exposure 178182.…”

“…Analysis of unmodified solvents in urine is regarded as specific biomarkers of exposure and correlate to occupational exposure 178182. GC has been commonly applied for determination of organic solvents in biological samples with detectors, such as a flameionization detector178181 and MS 183184. LC-MS/MS is also efficiently applied for determination of organic solvents after filtration and acidification of urine samples 180.…”

“…Toluene was reported in alveolar air, blood, and urine of male workers from a chemical factory 177. Dermal exposure study in workers of a petrochemical plant detected benzene in all the samples and toluene in 93% of samples 181. In Italy, a decreasing trend was observed in the levels of organic solvents in the paint industry workers in the past 2 decades due to usage of safety equipment and following of regulations 184.…”

Accuracy of a semiquantitative method for Dermal Exposure Assessment (DREAM)

“…Details of the methodology of five out of the six surveys have been published elsewhere. [17][18][19][20][21] Dermal exposure was assessed to metal working fluids (MWF) (survey 1, manufacturing of motor blocks), organic solvents (OS) (survey 2, spray painting), cyclophosphamide (CP) (survey 3, handling of antineoplastic drugs in hospitals), di-ethyl-glycol-butyl-ether (DEGBE) (survey 4, chemical industry), benzene (BZ) (survey 5, petrochemical industry), and toluene (TL) (survey 6, shoe manufacturing) for workers performing different tasks. Measurements were performed during the time a worker performed a specific task (surveys 2, 3, and 4) or during (part of) a shift (surveys 1, 2, 5, and 6).…”

Urinary S-phenylmercapturic Acid as a Key Biomarker for Measuring Occupational Exposure to Low Concentrations of Benzene in Chinese Workers

“…[1][2][3][4][5] There is an increasing public concern about environmental exposure to ambient levels of benzene as toxic air pollutant that need to be reduced. [1][2][3][4][5] There is an increasing public concern about environmental exposure to ambient levels of benzene as toxic air pollutant that need to be reduced.…”