The radiological accident in Goiania in 1987 caused a trail of human contamination, animal, plant and environmental by a radionuclide. Exposure to ionizing radiation results in different types of DNA lesions. The mutagenic effects of ionizing radiation on the germline are special concern because they can endures for several generations, leading to an increase in the rate of mutations in children of irradiated parents. Thus, to evaluate the biological mechanisms of ionizing radiation in somatic and germline cells, with consequent determination of the rate mutations, is extremely important for the estimation of genetic risks. Recently it was established that Chromosomal Microarray Analysis is an important tool for detecting wide spectra of gains or losses in the human genome. Here we present the results of the effect of accidental exposure to low doses of ionizing radiation on the formation of CNVs in the progeny of a human population accidentally exposed to Caesium-137 during the radiological accident in Goiânia, Brazil.

We evaluated 41 rural workers occupationally exposed to pesticides and 32 subjects as a control group, using the micronucleus (MN) and the comet assay. For the comet assay, we evaluated the peripheral blood, and for the MN, we sampled cells from the oral epithelium. Damage to DNA was measured by tail length, % DNA in tail (% tail), olive tail moment (OTM), and tail moment (TM). The exposed group presented an 8× increase in MN frequency, when compared to the control group (p <0.05). When we contrasted the MN frequencies between the individuals that use and do not use personal protective equipment, we found a mean of 7.5 MN (57 % variance) and 12.1 MN (130 % variance), respectively. The binucleated cells were 0.04 and 0.005, in the exposed and control groups, respectively, indicating 8× increase in the number of binucleated cells, when comparing the groups (p <0.05). In the comet assay, we demonstrated statistically significant differences in three parameters (% DNA, OTM, and TM) indicating that the rural workers presented high levels of genomic damages. Our results indicate that occupational exposure to pesticides could cause genome damage in somatic cells, representing a potential health risk to Brazilian rural workers that deal constantly with agrochemicals without adequate personal protection equipment.

No abstract

The frequency of micronuclei in both buccal cells and peripheral blood lymphocytes is extensively used as a biomarker of chromosomal damage and genome stability in human populations. We examined whether prolonged exposure to complex mixtures of pesticides leads to an increase in cytogenetic damage. The exposed group comprised 50 agricultural aviators, mainly from Central and Southeast regions of Brazil, who had inhaled agrochemicals for more than 10 years without personal protection equipment; the control group consisted of 17 men from the same regions, without indication of exposure to pesticides, There were three times higher frequencies of micronuclei (P < 0.05) and 2.5 times higher frequencies of binucleated cells in the aviators when compared to controls. However, cytotoxic alterations such as broken eggs and karyorrhexis did not present statistically significant differences between the exposed and control groups. Therefore, diverse agrochemicals used to combat pests in agriculture possess genotoxic effects in the oral mucosa of the agricultural pilots, as showed in this study.