Association between occupational exposure to benzene and chromosomal alterations in lymphocytes of Brazilian petrochemical workers removed from exposure

Abstract

We aimed to investigate the association between chronic exposure to benzene and genotoxicity in the lymphocytes of workers removed from exposure. The study included 20 workers with hematological disorders who had previously worked in the petrochemical industry of Salvador, Bahia, Brazil; 16 workers without occupational exposure to benzene served as the control group. Chromosomal analysis was performed on lymphocytes from peripheral blood, to assess chromosomal breaks and gaps and to identify aneuploidy. The Kruskal-Wallis test was used to compare the mean values between two groups, and Student's t test for comparison of two independent means. The frequency of gaps was statistically higher in and the exposed group than in the controls (2.13 ± 2.86 vs. 0.97 ± 1.27, p = 0.001). The frequency of chromosomal breaks was significantly higher among cases (0.21 ± 0.58) than among controls (0.12 ± 0.4) (p = 0.0002). An association was observed between chromosomal gaps and breaks and occupational exposure to benzene. Our study showed that even when removed from exposure for several years, workers still demonstrated genotoxic damage. Studies are still needed to clarify the long-term genotoxic potential of benzene after removal from exposure.

The association of three DNA repair genes polymorphisms on the frequency of chromosomal alterations detected by fluorescence in situ hybridization

“…The association between two dysfunctional polymorphisms RAD51 / G135C and ATM / P1054R, and CAs, as an early effect biomarker, was evaluated in this cross-sectional study. Numerous studies have associated exposure to BTEX with increased levels of CAs in circulating lymphocytes of exposed workers (Zhang et al 2002 , 2012 ; Santiago et al 2014 ; Gonçalves et al 2016 ). Increased levels of CAs have, in turn, been correlated with an increased risk of cancer, especially for hematologic malignancies, such as myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML)—(Smith 2010 ).…”

Tumors due to chronic exposure to benzene and biomarkers of exposure

“…This cytogenetic analysis from peripheral blood lymphocytes for the determination of radiosensitivity or mutation load detection expressed as "frequency of CAs" is a long-standing approach [36] . A study conducted in the Czech Republic reinforced the association between increased levels of CAs and the incidence of cancer and mortality [37] . In BTEX-exposed workers, CAs in peripheral blood lymphocytes were already reported based on conventional/banding cytogenetics [22,38,39] or chromosome painting by fluorescence in situ hybridization (FISH) [40][41][42][43][44][45][46] .…”

Histopathological and Biochemical Studies of Some Organs of Male Albino Rat Following Chronic Administration of Benzene

“…Human exposure to benzene has been associated with the range of acute and long-term adverse health effects and diseases, including cancer and aplastic anaemia (WHO, 2010).Furthermore, human exposure to benzene in work environment is a universal work-related health disorders (Uzma et al, 2008;Glass et al, 2010;Khalade et al, 2010;Tunsaringkarn et al, 2013 ;Nur-Hidayah et al, 2015 andHetal, 2016). Moreover,the results of De Aquino et al (2016) and Goncalves et al(2016) suggest that petrochemical workers and laboratory technicians who directly exposed to benzene and other organic solvents have increased levels of chromosomal damageand enhance the carcinogenesis risk. Benzene is the most common chemical known to cause liver injury .…”