Bitumen (asphalts) used for road pavement in Hungary have a low tar content since the 1960s. However, traditional bitumen, as a substance belongs to the IARC Group 2B of carcinogens, because of its tar content, which was radically reduced in the last decades to develop an environmentally friendly substance. Other carcinogens in the working environment which are used, are solvents such as crude oils (Group 1), and diesel exhaust gases (Group 2A). Lifestyle factors also affect the health status of road pavers. The aim of this study was to investigate the changes in health status and geno- and immunotoxicology parameters of asphalt exposed road pavers. Multiple end-point follow-up genotoxicology monitoring was performed in Hungarian road pavers between 1996-1999 and 2003-2006. The latter set was supplemented with immunotoxicological endpoints. Studied subjects were interviewed by a physician to collect data on age, medication, smoking and drinking habits, medical and work histories, and they took part in a routine clinical laboratory check-up, including hematology, liver and kidney function tests and risk factors. The multiple end-point genotoxicology monitor, developed in our laboratory, includes the determination of chromosome aberration (CA), sister-chromatid exchange, and HPRT mutation frequencies and the measurement of DNA repair performed in peripheral blood lymphocytes according to the standard methods. Immunotoxicology monitoring includes determination of lymphocyte subpopulations and the measurement of lymphocyte activation. Altogether 89 asphalt-exposed workers (23 managers, 23 hand pavers, 28 finishers and 15 mixers) were investigated. The results were compared to 33 non-exposed industrial controls. More than half of the studied subjects were active smokers and more than 80% were regular drinkers. Among the exposed the most frequent clinical symptoms were liver and kidney dysfunctions, hypertension, hyperglycemia, high cholesterol, rheumatoid complaints and high count of white blood cells. However, the low exposed management also suffered from hypertension, hyperglycemia and high cholesterol. For genotoxicology monitoring the most significant changes were in the mean CA yields. At the start (1996) CA was increased in exposed subjects. The highest CA was found among mixers, and CA was also elevated among finishers working in closed cabins and pavers cleaning equipment with crude oil. By 1999 the CAs of exposed subjects decreased and remained at the level of industrial controls, except that of mixers still above the control level in 2004. The immunotoxicological tests showed a shift of lymphocyte subpopulations both in the exposed workers and management controls as well as the activation of T and B cells. Alterations found in clinical parameters except rheumatoid complaints can be attributed to the lifestyles of the studied subjects. Data suggest that the main genotoxic agents were exhaust gases in the closed cabins among finishers and crude oil used for cleaning in pavers, as proper ventilation and the use of harmless detergents resulted in the decrease of CA yields.
- Health effects of bitumen exposure
- Road pavers
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health