Evaluation of the genetic alterations in direct and indirect exposures of hexavalent chromium [Cr(VI)] in leather tanning industry workers North Arcot District, South India

• Published in: International archives of occupational and environmental health Vol. 83; no. 7; pp. 791 - 801
• Main Authors: Balachandar, Vellingiri, Arun, Meyyazhagan, Mohana Devi, Subramaniam, Velmurugan, Palanivel, Manikantan, Pappusamy, Karthick Kumar, Alagamuthu, Sasikala, Keshavarao, Venkatesan, Chinnakulandai
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.10.2010; Springer; Springer Nature B.V
• Subjects: Adult; Air Pollutants - analysis; Analysis of Variance; Bioassays; Biological and medical sciences; Biomonitoring; Chemical and industrial products toxicology. Toxic occupational diseases; Chromium; Chromium - toxicity; Chromium - urine; Chromosome Aberrations - chemically induced; Comet Assay; DNA damage; Earth and Environmental Science; Environment; Environmental Exposure - adverse effects; Environmental Health; Human exposure; Humans; India; Leather & leather products; Lymphocytes; Medical sciences; Metals and various inorganic compounds; Micronuclei, Chromosome-Defective - chemically induced; Middle Aged; Occupational exposure; Occupational Exposure - adverse effects; Occupational health; Occupational Medicine/Industrial Medicine; Original Article; Rehabilitation; Risk Factors; Tanning; Tanning industry; Toxicity; Toxicology; Variance analysis; Young Adult; Asia; India; Human lymphocytes; Hexavalent chromium [(Cr(VI)]; Occupational exposure; Chromosome aberrations (CA); Micronuclei (MN); Comet assay; Chromosomal aberration; Human; Toxicity; Genotoxicity; Transition metal; Hexavalent chromium [Cr(VI)]; Tannery; Inorganic element; Leather industry; Genetics; Worker; Lymphocyte; Chromium VI; Occupational medicine; Genotoxity test
• ISSN: 0340-0131; 1432-1246
• DOI: 10.1007/s00420-010-0562-y

Purpose The focal aim of the present study was to identify the genetic alterations occurring in the tannery workers and surrounding inhabitants chronically exposed to hexavalent chromium [Cr(VI)]. Methods A total of 108 samples which includes 72 exposed subjects [36 directly exposed (DE) subjects and 36 indirectly exposed (IE) subjects] and 36 controls were recruited for this study. The exposed subjects and controls were selected based on the Cr level present in air and their urine. Directly exposed subjects were categorized based on their work duration in the tannery industries, whereas the indirectly exposed subjects were categorized based on their year of residence in the place adjacent to tannery industries for more than 3 decades. Controls were normal and healthy. Age was matched for the exposed subjects and controls. The exposed subjects as well as the controls were categorized based on their age (group I, <40 years; group II, >41 years). Cell cultures were established from blood samples (5 ml from each subject) collected from the subjects (exposed subjects and controls) after obtaining informed consent. G-banding (Giemsa staining) of the cultures, micronucleus (MN) assay and comet assay were used to identify the genetic alterations of individuals exposed to Cr(VI) in comparison with the controls. Results A higher degree of total CA [12 ± 8.49 (21–25 years)] and MN [18.69 ± 7.39 (11–15 years)] was found in DE subjects compared to other groups. In IE subjects, elevated levels of CA [5.67 ± 1.15 (51–60 years)] and MN [25 ± 9.89 (71–80 years)] were observed. As expected, controls exhibited minimal number of alterations. The overall CA frequency due to Cr exposure was significantly different from that of the controls for both chromatid and chromosome type aberrations ( P  < 0.05 by ANOVA). The MN/1,000 binucleated cells were significantly increased ( P  < 0.05) in the peripheral lymphocytes of DE and IE subjects in comparison with controls. The mean tail length of comet assay for DE, IE and controls were analyzed. The mean tail length of DE subjects [4.21 (3.21–10.98)] was higher compared to that of IE subjects [3.98 (2.98–11.27)] and controls [3.01 (2.68–9.40)]. Conclusion In conclusion, this work shows a clear genotoxic effect associated with chromium exposure, both directly and indirectly. Our result reinforces the higher sensitivity of cytogenetic assays for the biomonitoring of occupationally exposed populations. There is a strong need to educate those who work with potentially hazardous heavy about its adverse effects and highlight the importance of using protective measures.