Relationship between dermal exposure and PAH-DNA adducts in lymphocyte DNA in truck-drivers exposed to polycyclic aromatic hydrocarbons

Abstract

Background: Truck drivers in Pakistan are confronted with numerous respiratory problems mainly because no proper occupational safety guidelines exist and health monitoring services are rarely extended to them. Aim: We aimed to assess dermal contamination by Polycyclic Aromatic Hydrocarbons (PAHs) among 79 truck drivers who work for more than six hours per day. Methods: We took both skin pad and urine samples to measure dermal exposure by PAH and subsequent secretion through body. Pyrene was used as biological marker for dermal exposure. Results: The results show that truck drivers have high PAH dermal exposure. However, the mean pyrene exposure levels were reduced to 33% when painters wore masks during work. The biological measure for the internal exposure to PAHs was urinary 1-hydroxyprene whose concentration was relatively low (range 21 and 133 nmol) when compared to dermal exposure levels. PAH-DNA adducts were observed in lymphocytes DNA among one-third of the workers. Using multiple regression analysis, we identified mass balance between dermal pyrene dose and 1-hydroxyprene excretion that confirmed the relevance of the dermal exposure route. Our estimates of the dermal and urinary pyrene levels clearly indicate that an average of 52% of the total absorbed amount of pyrene enters the body through the skin. Conclusions: Study concludes that mitigation measures to reduce PAH exposure should be focused more on the reduction of dermal contamination by PAHs than any other route. Moreover, use of occupational safety guideline must be prepared and distributed among truck drivers.