Genotoxicity in Brazilian coal miners and its associated factors

Abstract

The present study aims to evaluate the potential genotoxic and associated factors among coal miners, divided by degree of exposure. Blood and buccal smears were collected from 158 workers, who actively participate in different activities in coal mining, and 48 individuals living in the same city but do not have participation in coal mining activities (control group). The workers were divided into three different groups, according to the level of contact with coal extraction. A questionnaire intended to identify factors associated with DNA damage was performed in participants. The results regarding oral mucosa micronucleus test showed a significant difference ( p < 0.001) of the worker groups 1 and 2 in relation to the control group, where the group 1 has a higher degree of exposure to coal than group 2. For the lymphocyte micronucleus test and comet assay, there was no significant difference between the exposed groups and control group. There is an association between the outcome and the fact of living in the municipality of the mining company and the exposure to radiation in the last 12 months. Besides, the multivariate analysis showed an association of the tail moment with radiation exposure in the last 12 months. Thus, the findings of this study reveal genotoxicity in oral mucosa cells of workers exposed to coal and that workers with higher degree of contact with coal have a more pronounced response.

Genotoxic risk in health-care professionals occupationally exposed to low doses of ionizing radiation

“…Regarding this information, the increased risk related to black skin is in line with studies that show that social vulnerability associated with exposure to environmental agents contributes to increased DNA damage (Da Silva Pinto et al, 2017; Da Silva Júnior et al, 2018a). Moreover, although exposure to radiation is commonly cited as a risk factor for the development of DNA damage, this parameter seems to be related to healthy habits of regular medical follow-up (Da Silva Júnior et al, 2018b). Therefore, the greater the number of X-rays taken during life the greater the protective effect, while a high number of X-rays in the short term (last 12 months) indicates a possible harmful exposure of genetic material.…”

“…Although exposure to IR may be directly related to DNA damage in biological systems, as described in the literature, many studies suggest that we must consider not only the environmental and occupational exposure factor but also socioeconomic factors and lifestyle, including stress, when evaluating occupationally chronic exposure (da Silva Júnior et al, 2018b; Jackson and Bartek, 2009)…”

Genetic Damage in Workers from the Rare Metal Ore Production Region

“…It should be noted that most of the works devoted to the study of genotoxic effects using the BMCyt assay in miners are related to coal mining [54,68,69,85,86]. In these works, the authors showed a significant increase in the frequency of MN in buccal epithelium cells in coal miners.…”

“…However, comet assay on various tissues is also used to assess DNA repair [65,66]. Thus, Brazilian researchers successfully combine the BMCyt assay and comet assay in human lymphocytes to assess genotoxicity and reparation when exposed to xenobiotics [67][68][69].…”

Response to letter to the editor “Genetic biomonitoring of professionals occupationally exposed to ionizing radiation: Theoretical concepts for scientific debate”

“…To identify micronuclei the criteria were: (1) they contained a rounded smooth perimeter suggestive of a membrane; (2) micronuclei were less than a third the diameter of the associated nucleus, but large enough to discern shape and color; (3) staining intensity was similar to that of the nucleus; (4) texture was similar to that of the nucleus; (5) they were in the same focal plane as the nucleus; and (6) an absence of overlap with, or bridge to, the nucleus. Furthermore, numerous studies of the research group have already been published with the micronucleus technique: in rodent models (da Silva Júnior et al, 2013a, 2013b; Garcia et al, 2016, 2017; Hort et al, 2019); amphibians (Josende et al, 2015); earthworms (da Silva Júnior et al, 2019); and humans (da Silva Júnior et al, 2018; da Silva Pinto et al, 2017). Finally, it is worth mentioning two other concerns addressed by our group to minimize possible errors or biases in our analyses: (1) the slides were photographed for, if necessary, a subsequent reinterpretation and (2) the entire reading of the slides was done blindly (each individual received a numeric code and the analyzer was unaware of the participant’s allocation within the groups).…”