Anxiety and depression following cumulative low-level exposure to organophosphate pesticides

Abstract

Previous research suggests that individuals with a prior history of pesticide poisoning are at increased risk of psychiatric disorder (Freire & Koifman, 2013), but findings regarding the impact of cumulative low-level exposure are inconsistent. The aim of the current study was to investigate whether sheep farmers with a history of low-level exposure to organophosphate pesticides (1) report a higher level of psychological distress on subjective symptom questionnaires, compared to unexposed controls (2) also meet internationally agreed diagnostic criteria for a psychiatric disorder more often than unexposed controls. 127 sheep farmers were evaluated and compared to 78 unexposed controls, matched in terms of gender, education, level of intelligence, working status and area of residence. Both self-report measures and structured clinical interviews were used to assess mental health. The exposed cohort reported significantly higher rates of anxiety and depression when self-report questionnaires were used to evaluate mood, even when stressful life events, demographic and physical health factors were taken into account. However, when diagnostic interviews were used to assess mood, this pattern only held true for anxiety.3

Exploring the Drivers of Irrigator Mental Health in the Murray–Darling Basin, Australia

“…Some studies have identified greater mental health issues and less life satisfaction amongst farmers than non-farmers [13]. The literature suggests that farmers' stress is attributable to pesticide exposure, financial difficulties, climate variability, injuries, regulations, uncertainty about the future, role conflict between work and home roles, and heavy workloads [13][14][15]. Most importantly, mental disorders have been recognised as one of the key risk factors for suicide and suicidal ideation in farmers [13,16].…”

“…One of the most researched aspects of farming and mental health is the link between the use of neurotoxic pesticides and neural systems (not used in certified organic farming) known to cause mental illness and depression [15]. Khan et al [2] found that organic farmers have a significantly lower frequency of neurological symptoms and depression.…”

Sex-Specific Neurotoxic Effects of Organophosphate Pesticides Across the Life Course

“…Adult OP exposure has been associated with adverse neurological outcomes including neuropsychiatric conditions [106], cognitive deficits, and neurodegenerative diseases; for review, see [28,43,107–108]. Some studies have failed to detect associations between occupational OP exposure and neurotoxicity, but this could be because the specific type of OP and individual susceptibility/sensitivity factors such as gene polymorphisms are rarely assessed [109].…”

Reliability and factorial validity of a questionnaire to assess organophosphate pesticide exposure to agricultural workers in Maule, Chile

“…Cognitive and motor difficulties are the most commonly described neurotoxic conditions associated with chronic occupational exposure to OPs (Starks et al 2012;Meyer-Baron et al 2015;Muñoz-Quezada et al 2016a, 2016bCorral et al 2017). Recent studies have also shown OP exposure is related to emotional disturbances (Mackenzie Ross et al 2010;Harrison and Mackenzie Ross 2016), asthma, allergies (Hoppin et al 2009), Parkinson's disease, neuropathy (Povey et al 2014) and cancer (Alavanja and Bonner 2012) and poorer neurodevelopment in children (Bouchard et al 2011;Rauh et al 2012).…”