Browsing by Autor "Kristian Dreij"

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Correction to: Pesticide exposure among Bolivian farmers: associations between worker protection and exposure biomarkers
(Springer Nature, 2019) Jessika Barrón Cuenca; Noemí Tirado; Max Vikström; Christian Lindh; Ulla Stenius; Karin Leander; Marika Berglund; Kristian Dreij
Correction: Pesticide exposure among Bolivian farmers: associations between worker protection and exposure biomarkers
(Springer Nature, 2021) Jessika Barrón Cuenca; Noemí Tirado; Max Vikström; Christian Lindh; Ulla Stenius; Karin Leander; Marika Berglund; Kristian Dreij
Genotoxic damage among Bolivian farmers exposed to a complex mixture of pesticides
(Elsevier BV, 2018) Jessika Barrón Cuenca; Noemí Tirado; J. Barral; Pablo Almaraz; Ulla Stenius; Marika Berglund; Kristian Dreij
Genotoxic damage in a Bolivian agricultural population exposed to a mixture of pesticides
(Wolters Kluwer, 2019) John H. Barron; Noemí Tirado; J. Barral; Christian Lindh; Ulla Stenius; Marika Berglund; Kristian Dreij
TPS 792: Occupational health 2, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM Pesticides are well-known chemicals that can increase the risk to develop cancer by induction of DNA damage and oxidative stress, especially in populations with chronic exposure. Bolivian farmers have been increasing their use of pesticides during the last decades to increase their production and economy. Chronic exposure to these chemicals, their combined effects and genetic polymorphisms can increase the risk of genotoxic damage, mutagenicity and development of chronic diseases. A cross-sectional study in 297 volunteers from three different Bolivian agricultural communities was conducted. Exposure and handling of pesticides were assessed by a questionnaire and urinary pesticide metabolite analysis. Genotoxic effects were evaluated in collected blood samples by Micronucleus and Comet assay. Frequency of glutathione transferase (GST) null genotypes (GSTM1 and GSTT1) was determined to evaluate the impact on DNA damage levels. The results showed that only 17% of the farmers used recommended protection equipment. In agreement, they were highly exposed to chlorpyrifos, pyrethroids and 2,4-D, and men generally more highly compared to women. Higher frequency of micronuclei (MN) was found in women compared to men (4.52 vs 3.55, p<0.05). Farmers active >8 years had higher frequency of MN compared to farmers active <8 years (4.23 vs 2.94, p<0.05). Surprisingly, a null GST genotype (GSTM1 and GSTT1: 84% and 24% null, respectively) was associated with lower levels of DNA damage. High levels of exposure to tebuconazole, 2,4-D or cyfluthrin was associated with high levels of DNA strand breaks (p<0.05-0.01). After adjustment for confounding factors (e.g. gender, age, GST genotype), a significant increased risk of DNA strand breaks was found for exposure to 2,4-D (OR=1.9, CI=1.0-3.8, p=0.049). In conclusion, agricultural Bolivian population, especially men are highly exposed to mixtures of pesticides causing genotoxic effects in lymphocytes and which constitutes an increased risk of developing cancer in the future.
Human Pesticide Exposure in Bolivia: A Scoping Review of Current Knowledge, Future Challenges and Research Needs
(Multidisciplinary Digital Publishing Institute, 2024) Jessika Barrón Cuenca; Kristian Dreij; Noemí Tirado
Numerous studies have shown that pesticide exposure is linked to adverse health outcomes. Nevertheless, in Bolivia, where there is an increasing use of pesticides, the literature is sparse. To address knowledge gaps and guide future research in Bolivia, we conducted a scoping review spanning 22 years (January 2000 to December 2022). Our search identified 39 peer-reviewed articles, 27 reports/documents on Bolivian regulations, and 12 other documents. Most studies focused on farmers and revealed high pesticide exposure levels, assessed through biomarkers of exposure, susceptibility, and effect. The literature explored a range of health effects due to pesticide exposure, spanning from acute to chronic conditions. Many studies highlighted the correlation between pesticide exposure and genotoxic damage, measured as DNA strand breaks and/or micronuclei formation. This was particularly observed in farmers without personal protection equipment (PPE), which increases the risk of developing chronic diseases, including cancer. Recent findings also showed the alarming use of banned or restricted pesticides in Bolivian crops. Despite existing Bolivian regulations, the uncontrolled use of pesticides persists, leading to harmful health effects on the population and increasing land and water pollution. This review underscores the need for the stringent enforcement of regulations and continued research efforts, and it provides a scientific foundation for decision-making by relevant authorities.
Human pesticide exposure in Bolivia: A scoping review of current knowledge, future challenges and research needs
(National Institute of Environmental Health Sciences, 2024) Jessika Barrón Cuenca; Jessika Barrón Cuenca; Kristian Dreij; Noemí Tirado
In vitro cytotoxicity and genotoxicity of single and combined pesticides used by Bolivian farmers
(Wiley, 2021) Jessika Barrón Cuenca; Marcos Felipe de Oliveira Galvão; Burcu Ünlü Endirlik; Noemí Tirado; Kristian Dreij
We previously showed that farmers in Bolivia are exposed to many pesticides, some at elevated levels, and that this was associated with increased risk of genetic damage. To improve the understanding of possible mixture effects, the cytotoxicity and genotoxicity of pesticides were studied in vitro using human liver HepG2 cells. The studied pesticides were 2,4-D, chlorpyrifos, cypermethrin, glyphosate, methamidophos, paraquat, profenofos, and tebuconazole. Three mixtures (U1, U2, and U3) were based on profiles of urinary pesticide metabolites and one mixture on the most frequently used pesticides (S1). The results showed that paraquat and methamidophos were the most cytotoxic pesticides (EC<sub>50</sub> ≤0.3 mM). Paraquat, chlorpyrifos, tebuconazole, and the U1, U2, and U3 mixtures, which contained a large proportion of either chlorpyrifos or tebuconazole, significantly increased intracellular ROS levels. Most pesticides activated DNA damage signaling through proteins Chk1 and H2AX. Strongest responses were elicited by paraquat, profenofos, chlorpyrifos, cypermethrin, and the S1 mixture, which contained 25% paraquat. Comet assay revealed significant increases of DNA damage in response to paraquat, cypermethrin, and U2 and S1 mixtures, which contained high levels of cypermethrin and paraquat, respectively. In summary, we showed that the tested pesticides, alone or in mixtures, in general induced oxidative stress and that most pesticides, and especially paraquat and cypermethrin, were genotoxic in HepG2 cells. We could also show that mixtures dominated by these two pesticides displayed a marked genotoxic potency, which agreed with our previous population studies.
Increased levels of genotoxic damage in a Bolivian agricultural population exposed to mixtures of pesticides
(Elsevier BV, 2019) Jessika Barrón Cuenca; Noemí Tirado; J. Barral; Imran Ali; Michael Levi; Ulla Stenius; Marika Berglund; Kristian Dreij
During the past decades, farmers in low to middle-income countries have increased their use of pesticides, and thereby the risk of being exposed to potentially genotoxic chemicals that can cause adverse health effects. Here, the aim was to investigate the correlation between exposure to pesticides and genotoxic damage in a Bolivian agricultural population. Genotoxic effects were assessed in peripheral blood samples by comet and micronucleus (MN) assays, and exposure levels by measurements of 10 urinary pesticide metabolites. Genetic susceptibility was assessed by determination of null frequency of GSTM1 and GSTT1 genotypes. The results showed higher MN frequency in women and farmers active ≥8 years compared to their counterpart (P < 0.05). In addition, age, GST genotype, alcohol consumption, and type of water source influenced levels of genotoxic damage. Individuals with high exposure to tebuconazole, 2,4-D, or cyfluthrin displayed increased levels of genotoxic damage (P < 0.05-0.001). Logistic regression was conducted to evaluate associations between pesticide exposure and risk of genotoxic damage. After adjustment for confounders, a significant increased risk of DNA strand breaks was found for high exposure to 2,4-D, odds ratio (OR) = 1.99 (P < 0.05). In contrast, high exposure to pyrethroids was associated with a reduced risk of DNA strand breaks, OR = 0.49 (P < 0.05). It was also found that high exposure to certain mixtures of pesticides (containing mainly 2,4-D or cyfluthrin) was significantly associated with increased level and risk of genotoxic damage (P < 0.05). In conclusion, our data show that high exposure levels to some pesticides is associated with an increased risk of genotoxic damage among Bolivian farmers, suggesting that their use should be better controlled or limited.
Pesticide exposure among Bolivian farmers: associations between worker protection and exposure biomarkers
(Springer Nature, 2019) Jessika Barrón Cuenca; Noemí Tirado; Max Vikström; Christian Lindh; Ulla Stenius; Karin Leander; Marika Berglund; Kristian Dreij
The use of pesticides has increased during the past decades, also increasing the risk of exposure to toxic pesticides that can cause detrimental health effects in the future. This is of special concern among farmers in low-to-middle-income countries that may lack proper training in the safe use of these chemicals. To assess the situation in Bolivia a cross-sectional study in three agricultural communities was performed (n = 297). Handling, use of personal protective equipment (PPE) and pesticide exposure were assessed by a questionnaire and measurements of urinary pesticide metabolites (UPMs). Results showed that methamidophos (65%) and paraquat (52%) were the most commonly used pesticides and that 75% of the farmers combined several pesticides while spraying. Notably, only 17% of the farmers used recommended PPEs while 84% reported to have experienced symptoms of acute pesticide poisoning after spraying. UPM measurements indicated high levels of exposure to chlorpyrifos, pyrethroids and 2,4D and that men generally were more highly exposed compared to women. Our study demonstrates that farmers who are better at following recommendations for pesticide handling and use of PPE had a significantly lower risk of having high UPM levels of most measured pesticides. Our results thus confirm the need of proper training of farmers in low-to-middle-income countries in proper protection and pesticide handling in order to reduce exposure levels and health problems.
Pesticide exposure and genotoxic effects among Bolivian farmers: A cross-sectional study
(Elsevier BV, 2017) Jessika Barrón Cuenca; Noemí Tirado; Christian Lindh; Marika Berglund; Kristian Dreij