Occupational risk assessment of organophosphates with an emphasis on psychological and oxidative stress factors

Redox imbalance and inflammation: A link to depression risk in brazilian pesticide-exposed farmers

This study aims to elucidate the mechanisms linking occupational pesticide exposure to depression among rural workers from Maravilha, Brazil. We assessed the mental health, oxidative, and inflammatory profiles of farmers exposed to pesticides (N = 28) and compared them to an urban control group without occupational exposure to pesticides (N = 25). Data on sociodemographic, occupational history, and clinical records were collected. Emotional states were evaluated using the State-Trait Anxiety Inventory (STAI) and Beck Depression Inventory (BDI). Biochemical, hematological, inflammatory, and redox parameters were examined in blood samples from both groups. Results showed educational disparities between groups and unveiled a concerning underutilization of personal protective equipment (PPEs) among farmers. Glyphosate was the predominant pesticide used by farmers. Farmers exhibited higher BDI scores, including more severe cases of depression. Additionally, elevated levels of creatinine, ALT, AST, and LDH were observed in farmers, suggesting potential renal and hepatic issues due to pesticide exposure. Oxidative stress markers, such as increased lipid peroxidation and superoxide dismutase (SOD) activity, along with decreased catalase (CAT) activity and ascorbic acid levels, were noted in the pesticide-exposed group compared to controls. Elevated levels of inflammatory cytokines, particularly IL-1β, IL-6 and TNF-α, were also observed in pesticide-exposed group. Our findings suggest that inflammation, oxidative distress and lower educational levels may be associated with depression in pesticide-exposed farmers. This study highlights the impact of occupational pesticide exposure on the mental health of rural workers. The underuse of PPEs and the link between depressive symptoms, inflammation, and oxidative stress underscore the urgent need for improved safety measures in agricultural practices. Addressing these issues will contribute to a deeper understanding of the intricate relationship between environmental exposures and mental health outcomes.

Brain-targeted nanoreactors prevent the development of organophosphate-induced delayed neurological damage

BACKGROUND

Organophosphate (OP)-induced delayed neurological damage is attributed to permanent neuropathological lesions caused by irreversible OP-neurocyte interactions, without potent brain-targeted etiological antidotes to date. The development of alternative therapies to achieve intracerebral OP detoxification is urgently needed.

METHODS

We designed a brain-targeted nanoreactor by integrating enzyme immobilization and biomimetic membrane camouflaging protocols with careful characterization, and then examined its blood-brain barrier (BBB) permeability both in vitro and in vivo. Subsequently, the oxidative stress parameters, neuroinflammatory factors, apoptotic proteins and histopathological changes were measured and neurobehavioral tests were performed.

RESULTS

The well-characterized nanoreactors exerted favourable BBB penetration capability both in vitro and in vivo, significantly inhibiting OP-induced intracerebral damage. At the cellular and tissue levels, nanoreactors obviously blocked oxidative stress, cellular apoptosis, inflammatory reactions and brain histopathological damage. Furthermore, nanoreactors radically prevented the occurrence of OP-induced delayed cognitive deficits and psychiatric abnormality.

CONCLUSION

The nanoreactors significantly prevented the development of OP-induced delayed neurological damage, suggesting a potential brain-targeted etiological strategy to attenuate OP-related delayed neurological and neurobehavioral disorders.

Could pesticide exposure be implicated in the high incidence rates of depression, anxiety and suicide in farmers? A systematic review

Pesticide exposure and poisoning may rise the risk of mental health problems and suicidal tendencies. To explore the potential connection between chronic occupational exposure to pesticides and depression, anxiety, and suicide-related outcomes in farmers, a systematic review was performed. Systematic review protocol is available in PROSPERO registration number CRD42022316285. A total of fifty-seven studies met inclusion criteria: twenty-nine on depression or other mental disorders, twelve on suicide (two of them on both depression and suicide), and fourteen on pesticide poisoning or self-poisoning and death. Among the fifty-seven selected studies, eighteen were conducted in Asia, seventeen in North America, fourteen in South America, seven in European Union, one in Africa, and one in Australia/Oceania. Selected studies demonstrated an increased prevalence of depressive disorders in farmworkers exposed to pesticides as well as an increased self-reported prevalence of depression in this population. Moreover, previous pesticide poisoning increased the risk estimates for depression or other mental disorders as compared with chronic pesticide exposure. Severe pesticide poisoning and multiple poisoning showed increased risks of depressive symptoms compared with milder cases. In addition, financial difficulties and poor health were positively correlated with depression. Among studies on suicide, nine of them found that suicide rates increased in areas devoted to agriculture with intensive pesticide consumption. Moreover, studies demonstrate a higher suicide risk among farmers. The present review suggests more attention to the farmer's mental health and more detailed studies on occupational exposure to the mixture of these compounds.

Association between organophosphorus insecticides exposure and the prevalence of sleep problems in the US adults: An analysis based on the NHANES 2007-2018

OBJECTIVE

The aim of this study was to evaluate the association between organophosphorus pesticides (OPPs) exposure and sleep problems.

METHODS

In this study, data from 6295 participants aged 18 years or older were collected from the National Health and Nutrition Examination Survey (NHANES). The dialkyl phosphate compounds (DAPs) metabolites, OPPs exposure biomarker, were examined using solid phase extraction-high coupled with isotope dilution-ultrahigh performance liquid chromatography-tandem mass spectrometry. Data on short sleep duration (SSD), self-reported trouble sleeping and self-reported sleep disorder were collected from the database. Weighted generalized logistic model, weighted quantile sum (WQS) model, and quantile-based g calculation (QGC) methods were used for analyzing the collected data.

RESULTS

The prevalence of SSD, self-reported trouble sleeping and self-reported sleep disorder in this study were 28.91 % (1814/6274), 25.31 % (1593/6294), and 9.05 % (289/3195), respectively. After confounding factors adjustments, the prevalence of SDD in participants with high log-transformed DETP, DMTP, DEDTP, and DMDTP were 1.19 times (OR: 1.11-1.28, P < 0.001), 1.09 times (OR: 1.03-1.15, P = 0.003), 1.26 times (OR: 1.17-1.37, P < 0.0001), and 1.10 times (OR: 1.04-1.17, P = 0.003) than in participants with low showed, respectively. A non-linear relationship was noted between SSD with the urinary concentration of DEP (P for nonlinearity < 0.001), DMP (P for nonlinearity < 0.001), DMTP (P for nonlinearity = 0.006), and DMDTP (P for nonlinearity = 0.001). The WQS results showed that the prevalence of SDD was 1.28 times (95 % CI: 1.17-1.40, P < 0.001) higher in participants with high co-exposure to OPPs than in those with low co-exposure, with DEDTP having the enormous weights (0.50). The QGC results also revealed a significant positive association between the co-exposure of DAPs and SSD (OR: 1.08, 95 % CI:1.02-1.16, P = 0.01) with DETP having the most positive weight (0.44). As for the association between DAPs with self-report sleep disorder, only DEP was detected that it was positively associated with self-reported sleep disorder with all confounding factors adjusted (OR: 1.17; 95 % CI: 1.07-1.29, P = 0.001). However, all DAPs have not detected a significant association with the prevalence of self-reported trouble sleeping. Besides, there was no significant association between co-exposure to OPPs with self-reported trouble sleeping and self-reported sleep disorder.

CONCLUSION

The results of this study indicated that high levels of single or mixture urinary DAP, indicating for OPPs exposure, were associated with an increased prevalence of SSD in general adults, which has significant implications for preventing OPPs pollution and protecting sleep health.

Exposure to Insecticides Modifies Gene Expression and DNA Methylation in Hematopoietic Tissues In Vitro

The evidence supporting the biological plausibility of the association of permethrin and malathion with hematological cancer is limited and contradictory; thus, further studies are needed. This study aimed to investigate whether in vitro exposure to 0.1 μM permethrin and malathion at 0, 24, 48 and 72 h after cell culture initiation induced changes in the gene expression and DNA methylation in mononuclear cells from bone marrow and peripheral blood (BMMCs, PBMCs). Both pesticides induced several gene expression modifications in both tissues. Through gene ontology analysis, we found that permethrin deregulates ion channels in PBMCs and BMMCs and that malathion alters genes coding proteins with nucleic acid binding capacity, which was also observed in PBMCs exposed to permethrin. Additionally, we found that both insecticides deregulate genes coding proteins with chemotaxis functions, ion channels, and cytokines. Several genes deregulated in this study are potentially associated with cancer onset and development, and some of them have been reported to be deregulated in hematological cancer. We found that permethrin does not induce DNA hypermethylation but can induce hypomethylation, and that malathion generated both types of events. Our results suggest that these pesticides have the potential to modify gene expression through changes in promoter DNA methylation and potentially through other mechanisms that should be investigated.