Alterações clínicas e laboratoriais relacionadas à exposição crônica ao benzeno, tolueno, etilbenzeno e xilenos nos trabalhadores de postos de combustíveis na cidade do Rio de Janeiro

Abstract

Gas station workers (GSW) are daily exposed to harmful petroleum-derived hydrocarbons (benzene, toluene, ethylbenzene, and xylenes - BTEX). The aim of this study was to evaluate the clinical complaints, laboratory alterations and genotoxic effects in GSW. This is a quantitative case-control and qualitative study with the application of a questionnaire with semi-structured questions, carried out at four petrol stations randomly distributed in the city of Rio de Janeiro. Healthy individuals, without prior exposure to BTEX and in the same age group, were used as controls. Overall, 89 workers (50.5% M e 49.5% F) were recruited versus 127 controls (54.5% M and 45.5% F). Two patients admitted to our hospital, previously denoted occupationally to BTEX, were also included. To test the influence of the time of exposure, we divided the workers into two groups arbitrarily: Group 1 (G1), with the short time of exposure, ≤ 3 years; and Group 2 (G2), with the longer time of exposure, > 3 years. The most relevant complaints were headache (32%) and fatigue (20%), lipothymia (11%), and less commonly: sleeplessness (5%), drowsiness (4%), irritability (3%), and pruritus (1%). The workers presented concerning alterations found in the blood. Anemia (21.6%), leukocytosis (11.4%) and polycythemia (5.7%) were the most frequent. Normochromic and normocytic anemia was seen in 5% of GSW, it was not associated with a higher LDH rate. Hepatic enzymatic damage showed increased gamma Glutamil-transferase in 6.3% as well as LDH, bilirubin and AST. Alcoholic histories were reported in 12% of the samples. The MN (micronucleus test) was significant for the total workers group (P = 0.034). MN frequency was significant for the total group GSW (35.5%) compared to control (11.8%). Comet assay indicated higher in the GSW group (40/44,5% comets in 89 subjects analyzed, varying in all classes and 18/14,2% between 127 controls). As for the length of the comets, they were significantly higher for G1 (P = 0.01) and for total workers (P = 0.01). For G2 the significance was borderline (P = 0.05). The present study showed damage in the healthiness of GSW, these results indicated DNA damage and confirmed their clinical complaints, laboratory alterations and genotoxicity tests as urgent measures for prevention. Their insufficient health care was under discussion.