Objective Large quantities of pesticides are used in rice crops. The aim of this study is to characterize how farmers are exposed to pesticides and subsequent poisoning. Materials and Methods A multilevel (individual and community) multi-method study, which included ethnographic and survey methods, as well as measurement of pesticides in water and human samples, was performed. Results The production process is described and the main risk factors are presented. Pesticides are considered the greatest danger at work and at their homes. Workers have poor working conditions and are not protected by the system of occupational risks. Azinphos-methyl, endosulfan, β-BHC, bromophos-methyl, bromophos-ethyl and 2,4- DDT were found in water samples. The survey included 381 workers with mild (12.86 %), moderate (67.98 %) and severe (5.51 %) poisonings respectively. Severe cases presented lower levels of education, lower levels of health care access to the contributory regimen of the Colombian social security system and higher incidence of cardiovascular disease, diabetes, herpes or other viral infections. Conclusion There are precarious working conditions that favor exposure to pesticides correlated to the exclusion of farmers from the occupational risk system, to poverty and to poor education. It is urgent to include these workers to the system of occupational risk system and to improve their living conditions, thus reducing unsafe practices when handling pesticides.

BackgroundFor several years, cell-free DNA has been emerging as an important biomarker for non-invasive diagnostic in a wide range of clinical conditions and diseases. The limited information available on the genotoxic effects associated with occupational exposure to car paints, as well as the fact that up-to-date there are not reports about cell-free DNA measurements for assessing this condition, led us to evaluate the DNA damage caused by the occupational exposure to organic solvents contained in car paints, through the quantification of the cell-free DNA and the comet assay, in a sample of 33 individuals taken from 10 automobile paint shops located in Bogota DC, Colombia.ResultsBy applying the two methods, cell-free DNA and comet assay, we found a significant increase in the extent of DNA damage in the exposed individuals compared with the non-exposed ones within the control group.ConclusionsOur findings provide useful information about the cell-free DNA levels in this type of exposure and can be considered as a support tool that contributes to the diagnosis of genotoxic damage in individuals occupationally exposed to car paints.Electronic supplementary materialThe online version of this article (doi:10.1186/s12995-016-0123-8) contains supplementary material, which is available to authorized users.

Mercury (Hg) exposure is a public health concern due to its persistence in the environment and its high toxicity. Such toxicity has been associated with the generation of oxidative stress in occupationally exposed subjects, such as artisanal gold miners. In this study, we characterize occupational exposure to Hg by measuring blood, urine and hair levels, and investigate oxidative stress and DNA methylation associated with gold mining. To do this, samples from 53 miners and 36 controls were assessed. We show higher levels of oxidative stress marker 8-OHdG in the miners. Differences in LINE1 and Alu(Yb8) DNA methylation between gold miners and control group are present in peripheral blood leukocytes. LINE1 methylation is positively correlated with 8-OHdG levels, while XRCC1 and LINE1 methylation are positively correlated with Hg levels. These results suggest an effect of Hg on oxidative stress and DNA methylation in gold miners that may have an impact on miners’ health.

Women are primarily exposed to mercury through the consumption of fish contaminated by gold mining activities. The main systems affected are the central nervous and renal systems, although effects on the reproductive system have also been found. Objective: To explore the relationship between mercury levels in women and their possible sources of contamination. A cross-sectional study was conducted from 2013 to 2015 with women residing in 11 municipalities in La Mojana, Colombia, using non-random sampling. Standardized instruments were used to identify sociodemographic characteristics, mercury use, mining-related activities, water and fish consumption, and other factors. Blood, urine, and hair samples were taken to quantify mercury levels. A logistic regression model was used to identify factors associated with elevated mercury values in the participants’ samples. A total of 428 women were included, with an average age of 36.7 ± 16.7 years, 3.3% of whom were pregnant at the time of the survey and 8.4% of whom were exposed occupationally. High levels of mercury were present in 62.8% of the women, in any one of the three samples processed. Those exposed occupationally and environmentally had similar values (p = 0.821). Frequency of fish consumption and source of drinking water were associated with higher levels of mercury (p < 0.05).

To mitigate the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), vaccines have been rapidly developed and introduced in many countries. In Colombia, the population was vaccinated with four vaccines. Therefore, this research aimed to determine the ability of the vaccines introduced in the National Vaccination Plan to prevent SARS-CoV-2 infection and induce seroconversion and sought to investigate the longevity of antibodies in the blood. We conducted a prospective, nonprobabilistic, consecutive cross-sectional cohort study in a population with access to vaccination with CoronaVac, Ad26.COV2.S, AZD1222, and BNT162b2 from March 2021 to March 2022. The study included 1327 vaccinated people. A plurality of participants were vaccinated with BNT162b2 (36.1%; n = 480), followed by Ad26.COV2.S (26.9%; n = 358), CoronaVac (24%; n = 331), and AZD1222 (11.9%; n = 158). The crude seroprevalence on day zero varied between 18.1% and 57.8%. Participants who received BNT162b2 had a lower risk of SARS-CoV-2 infection than those who received the other vaccines. Participants who were immunized with BNT162b2 and AZD1222 had a higher probability of losing reactivity on day 210 after receiving the vaccine.