Potential Effects on Mental Health Status Associated with Occupational Exposure to Pesticides among Thai Farmers

Depressive symptoms and suicide attempts among farmers exposed to pesticides

Pesticides safeguard crop health but may diminish cholinesterase activity in farmers, potentially leading to psychiatric disorders like depression and suicide attempts. This study, with 453 participants (225 pesticide-exposed farmers, 228 non-farmers) in Almería, Spain, aimed to investigate the presence of depressive symptoms and suicide attempts, the decrease acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity, and their relationship with pesticide exposure in farmers. Depressive symptoms were evaluated using the Spanish adaptation of the Beck Depression Inventory, and blood samples were analyzed for AChE and BChE activity. Farmers showed significantly increased risk of moderate/severe depression and suicide attempts compared to non-farmers (OR = 2.18; p = 0.001), with highest risks observed among mancozeb users (OR = 2.76; p = 0.001 for depression) and malathion users (OR = 3.50; p = 0.001 for suicide attempts). Findings emphasize elevated depression and suicide risks among pesticide-exposed farmers, particularly associated with chlorpyrifos, mancozeb, and malathion exposure.

Environmental pollution and extreme weather conditions: insights into the effect on mental health

Environmental pollution exposures, including air, soil, water, light, and noise pollution, are critical issues that may implicate adverse mental health outcomes. Extreme weather conditions, such as hurricanes, floods, wildfires, and droughts, may also cause long-term severe concerns. However, the knowledge about possible psychiatric disorders associated with these exposures is currently not well disseminated. In this review, we aim to summarize the current knowledge on the impact of environmental pollution and extreme weather conditions on mental health, focusing on anxiety spectrum disorders, autism spectrum disorders, schizophrenia, and depression. In air pollution studies, increased concentrations of PM2.5, NO2, and SO2 were the most strongly associated with the exacerbation of anxiety, schizophrenia, and depression symptoms. We provide an overview of the suggested underlying pathomechanisms involved. We highlight that the pathogenesis of environmental pollution-related diseases is multifactorial, including increased oxidative stress, systematic inflammation, disruption of the blood-brain barrier, and epigenetic dysregulation. Light pollution and noise pollution were correlated with an increased risk of neurodegenerative disorders, particularly Alzheimer's disease. Moreover, the impact of soil and water pollution is discussed. Such compounds as crude oil, heavy metals, natural gas, agro-chemicals (pesticides, herbicides, and fertilizers), polycyclic or polynuclear aromatic hydrocarbons (PAH), solvents, lead (Pb), and asbestos were associated with detrimental impact on mental health. Extreme weather conditions were linked to depression and anxiety spectrum disorders, namely PTSD. Several policy recommendations and awareness campaigns should be implemented, advocating for the advancement of high-quality urbanization, the mitigation of environmental pollution, and, consequently, the enhancement of residents' mental health.

Mental Health Disorders among Thai Farmers: Occupational and Non-Occupational Stressors

This cross-sectional study aimed to identify occupational and non-occupational factors that impact levels of stress, depression, and anxiety among farmers located in the northern part of Thailand, including the potential psychological impacts of pesticide use. The participants (N=270) were interviewed with a survey adopted and modified from peer-reviewed articles and questionnaires. The survey consists of four parts, including demographic information and pesticide exposure; perceived farm stressors employing Farm Stressor Survey (FSS); mental health disorder utilizing Srithanya Stress Scale (ST5), Nine-Questions Depression- Rating Scale (9Q), and Depression Anxiety Stress Scale 21 (DASS21); in addition to COVID-related stress utilizing COVID Stress Scale (CSS). The participants were categorized into two groups i.e., Spray and No Spray based on their self-reported occupational use of pesticide spraying within the past year. No significant associations were observed between occupational pesticide exposures and mental health disorder scores. Being female, having a second job besides a farmer, having applied pesticides for greater than 20 years, and having a higher farm stressor perception showed a significant positive association with self-reported mental health disorders; while having a good agricultural practice and PPE use showed a significant negative association with those outcomes. This pilot study scrutinized expanded sources of stress in farm work and provided information for the development of more effective mental disorder intervention programs for Thai farmers.

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.

Carbofuran pesticide toxicity to the eye

Pesticide exposure to eyes is a major source of ocular morbidities in adults and children all over the world. Carbofuran (CF), N-methyl carbamate, pesticide is most widely used as an insecticide, nematicide, and acaricide in agriculture, forestry, and gardening. Contact or ingestion of carbofuran causes high morbidity and mortality in humans and pets. Pesticides are absorbed in the eye faster than other organs of the body and damage ocular tissues very quickly. Carbofuran exposure to eye causes blurred vision, pain, loss of coordination, anti-cholinesterase activities, weakness, sweating, nausea and vomiting, abdominal pain, endocrine, reproductive, and cytotoxic effects in humans depending on amount and duration of exposure. Pesticide exposure to eye injures cornea, conjunctiva, lens, retina, and optic nerve and leads to abnormal ocular movement and vision impairment. Additionally, anticholinesterase pesticides like carbofuran are known to cause salivation, lacrimation, urination, and defecation (SLUD). Carbofuran and its two major metabolites (3-hydroxycarbofuran and 3-ketocarbofuran) are reversible inhibitors of acetylcholinesterase (AChE) which regulates acetylcholine (ACh), a neurohumoral chemical that plays an important role in corneal wound healing. The corneal epithelium contains high levels of ACh whose accumulation by AChE inhibition after CF exposure overstimulates muscarinic ACh receptors (mAChRs) and nicotinic ACh receptors (nAChRs). Hyper stimulation of mAChRs in the eye causes miosis (excessive constriction of the pupil), dacryorrhea (excessive flow of tears), or chromodacryorrhea (red tears). Recent studies reported alteration of autophagy mechanism in human cornea in vitro and ex vivo post carbofuran exposure. This review describes carbofuran toxicity to the eye with special emphasis on corneal morbidities and blindness.