Characterization of soil remediation workers’ dermal exposure to polycyclic aromatic compounds

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that are composed by at least two aromatic rings. PAHs can be found in coal and petroleum, but can also be formed from incomplete combustion of for example fossil fuels, tobacco, wood and when smoking food. PAHs has been shown to cause several health risks such as carcinogenic effects, which led to that the U.S Environmental Protection Agency (U.S. EPA) selected 16 PAHs as priority pollutants. Those 16 PAHs is usually analysed when investigating PAH exposure. To analyze dermal exposure of PAHs a tape-stripping technique can be used. The tape-stripping method involves that a tape piece is placed on the skin to absorb the present PAHs and then the tape is removed and the PAHs can be extracted and cleaned-up from the tape. The aim of this study is to optimize a recently elaborated clean-up method for PAHs sampled by the tape-stripping technique. Also, to apply the method and measure the dermal exposure of 16 PAHs among soil remediation workers. Two clean-up methods were evaluated, Florisil SPE columns and deactivated silica (10%). Clean-up using Florisil columns were evaluated using 10 and 12 ml of n-hexane. For elution, poor recoveries were achieved for both elution volumes tested. On the other hand, tests using deactivated silica generated good recoveries for both elution solvents tested (i.e. 4 ml n-hexane:dichloromethane + 4 ml dichloromethane and 8 ml n-hexane). As for the elution solvents, no significant difference could be seen in the recoveries and the mixture of n-hexane and dichloromethane was used for the real samples. The dermal exposure of PAHs for the soil remediation workers were investigated using dermal tapes from the palm and neck of 18 soil remediation workers. Samples from the palm were sampled before and after a working day and there was a small difference between the total PAH concentration before and after a work-shift. For all categories of workers (office staff, machine operators and persons performing sampling) an increase in dermal concentration of PAHs could be observed for ten of the workers, but this increase were highest among the workers active in taking samples at the contaminated site. However, an increase in PAH exposure was not observed for all study participants and possible this is due to hand-washing after toilet visits. Overall, the concentrations of PAHs on the dermal samples from soil remediation workers were low, especially in comparison to other occupations such as chimney sweeps and pavers where PAH exposure is known to exist. The detected PAHs on the dermal tapes corresponded to PAH profiles in soil samples from the site.