Determination of Genetic Damage and Urinary Metabolites in Fuel Filling Station Attendants
P.V. Rekhadevi, M. Mahboob, M.F. Rahman, and Paramjit Grover*
Toxicology Unit, Biology Division, Indian Institute of Chemical Technology, Hyderabad 500 607, Andhra Pradesh, India
Fuel (diesel and petrol) constitutes a complexmixture of volatile ﬂammable liquid hydrocarbons among them benzene (BZ), toluene (TOL), and xylene (XYL) are considered to be the most hazardous, predominantly BZ because of its carcinogenic potency. Exposure to these compounds may have an impact on the health of the exposed subjects. Hence, genotoxicity and quantitative analysis of these compounds was performed in blood and urine samples of 200workers exposed to fuel in ﬁlling stations and compared to controls. The level of genetic damage was determined by micronucleus test (MNT) in buccal epithelial cells (BEC) and chromosomal aberrations (CA) assay in peripheral blood lymphocytes (PBL) of fuel ﬁlling station attendants (FFSA) and compared to a matched control group. Urine analysis for BZ and its metabolites, phenol (Ph), trans,trans-Muconic Acid (t, t-MA), and S-Phenyl Mercapturic Acid (S-PMA) was done in all the study subjects. The results of our study revealed that exposure to BTX in petrol vapors induced a statistically signiﬁcant increase in the frequency of micronuclei (MN) and CA in the exposed subjects than in controls (P < 0.05). There was a signiﬁcant rise in the levels of urinary BZ, Ph, t, t-MA, and S-PMA in theexposed subjects. Our study highlights the signiﬁcance of MNT, CA, and urinary metabolites as potential biological exposure indices of genetic damage in FFSA. This study suggests the need for regular monitoring of FFSA for possible exposure to BTX as a precautionary and preventive step to minimize exposure and reduce the associated health risks. Environ. Mol. Mutagen. C 00:000–000, 2010. V 2010Wiley-Liss, Inc.
Key words: genotoxicity; chromosomal aberrations; micronucleus test; urinary metabolite analysis
INTRODUCTION Countless people all over the world in various occupations have the probability of being exposed to hazardous materials. Undesirable health effects in some of them can be due to exposure to these substances. Among them fuel (petrol and diesel) ﬁlling station attendants(FFSA) are potentially exposed to a wide range of petroleum derived components like benzene (BZ) and its related compounds, such as toluene (TOL) and xylene (XYL) from fuel and vehicular exhausts [Roma-Torres et al., 2006]. BZ, TOL, and XYL (BTX) are used as raw materials for petrol and petroleum-based products. BZ is a natural component of crude oil and has been in use since decades. Therecognition of its carcinogenic property led to the restriction of its use. However, removal of lead based antiknocks from gasoline resulted in the blending of about 5% BZ in fuel [Verma and Tombe, 2002]. BZ is classiﬁed as a human carcinogen and the American Conference of Governmental Industrial Health (ACGIH) recommends a threshold limit value-time weighted average (TLV-TWA) of 0.5 ppm (parts permillion) of BZ for occupational exposures. TOL and XYL are also blended into petrol, together with
C V 2010 Wiley-Liss, Inc.
BZ. They have not proven to be toxic or carcinogenic to humans and animals and are not classiﬁed as human carcinogens [ACGIH, 1995]. Attention has to be paid to monitor groups of population exposed to toxic chemicals in fuel in their occupational environment so that workers atrisk can be identiﬁed. Reliable exposure assessments in exposed workers are required since the carcinogenicity and toxicity of these compounds has been matter of concern in occupational exposure. Genotoxicity has a signiﬁcant association with cancer. Evaluation of genetic damage in populations exposed in work places is most valid for predicting health risk. Biomarkers to ascertain genotoxicity...