Increased cytogenetic damage in a zone in transition from agricultural to industrial use: comprehensive analysis of the micronucleus test in peripheral blood lymphocytes

Abstract

A complex situation of chemical exposure has been described in México in a zone that is in transition from rural activities towards intensive industrialization, which has brought environmental pollution: chloroform, methylene chloride, indigo and toluene are some of the pollutants found in the Atoyac and Xochiac rivers. A biomonitoring study was planned in order to establish whether there was a biological effect due to the environmental situation. Communities where leukaemia and thrombocytopenic purpura cases have been reported were included in the study, as well as other communities where such cases have not been described. Three occupations were distinguished, according to chemical exposure: industrial workers, agricultural workers and workers in households, education and commerce. A comprehensive analysis in the micronucleus (MN) test was used to study genotoxicity biomarkers. Two metabolic polymorphisms were determined, namely, glutathione transferase mu1 (GSTM1) and theta1 (GSTT1), which are relevant when oxidative responses are involved. Increased genotoxic damage was found, including cells with >1 MN, >1 chromatin bud, and nucleoplasmic bridges. The genotoxic damage was differentially distributed in the regions studied, being more affected those that are closer to the Atoyac and Xochiac rivers, indicating an effect due to environmental exposure to the contaminants present in the rivers. Further characterization of the exposure regimes in these communities will be done in order to contribute to the alleviation of the health risks that environmental pollution is posing on the inhabitants of this area.

Assessment of exposure to organochlorine pesticides and levels of DNA damage in mother–infant pairs of an agrarian community

“…Only recently, endosulfan and HCH were reported to be clearly clastogenic [Tisch et al, 2005, Bajpayee et al, 2006, Jamil et al, 2004, whereas DDE was shown to be weakly genotoxic while HCB was not [Ennaceur et al, 2008]. Healthy adult individuals, nonsmokers, between 20 and 60 years old, living in Mexico City, had MN frequencies (0.6% 6 0.5) similar to those of the UCs in this study (0.78% 6 1.03); while the mothers in this study had higher MN frequencies than both of those groups (1.1% 6 0.7) (signed rank test, P 5 0.02) but lower levels (signed rank test, P 5 0.02) than nonsmoking adults (1.8% 6 1.3) living on the banks of a polluted river [Montero et al, 2006], We conclude that MN levels in the mothers can be attributable to their exposure, whereas, it appears that the UCs presented a low level of cytogenetic damage in spite of the fact that they received a large part of the load of pesticides present in the mothers' blood. We found no relationship between these biomarkers and the levels of any of the pesticides measured.…”

“…The BrdU incorporation method was used to identify proliferating cells [Serrano and Montero, 2001;Montero et al, 2006]. Whole blood samples were incubated at 378 in triplicate cultures for UC and in duplicate for mothers, in RPMI-1640 and phytohemagglutinin-M to stimulate T-lymphocyte proliferation, and 12 micromolar BrdU (final concentration).…”

Micronuclei in Bone Marrow and Liver in relation to Hepatic Metabolism and Antioxidant Response due to Coexposure to Chloroform, Dichloromethane, and Toluene in the Rat Model

“…We became interested in this subject due to the fact that these three compounds have been detected in rivers polluted with industrial waste affecting animal populations; due to their high volatility these pollutants can be spread through the air and contaminate large areas, constituting a risk of exposure for every living being around. Particularly, these polluted rivers are very close to inhabited areas of agricultural activity [11, 12]. …”

Increased frequency of micronuclei in the lymphocytes of patients chronically infected with hepatitis B or hepatitis C virus

“…For each individual, 2,000 binucleated cells were analysed for the presence of MN, NPBs and NBUDs in accordance with previously established criteria ( Fenech et al 2003 ). We calculated the frequency of each biomarker (number in 1,000, ‰) using the following formula: ‰ of X = (number of X/2,000) x 1,000, where X is MN, NPBs or NBUDs ( Montero et al 2006 ).…”