Genotoxicity in adult residents in mineral coal region—a cross-sectional study

Abstract

The present study assessed the DNA damage in environmentally exposed volunteers living in seven municipalities in an industrial coal region, through the use of the comet assay with blood cells and the micronucleus test with buccal cells. Blood and buccal smears were collected from 320 male volunteers living in seven cities inserted in a coal region. They were ages of 18 and 50 years and also completed a questionnaire intended to identify factors associated with DNA damage through a Poisson regression analysis. The comet assay detected significant differences in DNA damage in volunteers from different municipalities, and neighboring cities (Pedras Altas, Aceguá, and Hulha Negra) had a higher level of DNA damage in relation to control city. Some of the risk factors associated with identified DNA lesions included residence time and life habits. On the other hand, the micronucleus test did not identify differences between the cities studied, but the regression analysis identified risk factors such as age and life habits (consumption of mate tea and low carbohydrates diet). We conclude that there are differences in the DNA damage of volunteers from different cities of the carboniferous region, but the presence of micronuclei in the oral mucosa does not differ between the same cities. Furthermore, we alert that some related factors may increase the risk of genotoxicity, such as residence location and time, and living and food habits. Finally, we suggest the need for continuous biomonitoring of the population, as well as for investing in health promotion in these vulnerable populations.

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

“…After informed consent was obtained from each individual, an established questionnaire (Da Silva Pinto et al, 2017) was applied to obtain information regarding socioeconomic and life habits of all participants working in the hospital department. Socioeconomic information and life habits included sex, age, annual income, smoking, alcohol consumption, drug use (for both medical and recreational purposes), chimarrão consumption (typical local drink based on yerba mate) medical history, family cancer incidence or genetic predisposition, number of X-rays exposure throughout life (how many times the participant had X-ray used for a diagnostic purpose), and X-ray exposure in the past 12 months, for own medical purpose.…”

“…DNA damage was detected by the comet assay according to the basic alkaline technique of Singh et al (1988) with modifications by Pinto et al (2017). First, blood samples (15 µL) were mixed with low-melting point agarose at 37°C and embedded on two microscopes slides previously coated with normal melting-point agarose processed at 60°C.…”

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).…”