Objective: Organophosphates are a class of insecticides used globally by the agricultural industry for insect control. Acute consequences of organophosphate exposures are well known, while there has been limited research on their long-term effects.The objective of this review was to discuss the health effects of chronic organophosphate exposure in farmers.
Methods: Medline, Scopus and Web of Science were searched to find the relevant articles. Articles published only in English and until Decemember-2018 were reviewed. The selected articles were then divided into neurological (neurobehaviour, neurodevelopmental, neurological signs and symptoms) and non-neurological subheadings.
Results: Fifty-three articles for neurological effects and 17 articles for non-neurological effects were identified. Chronic organophosphates exposure was associated with deficits in the neurobehaviour subsets of attention and short-term memory, increased incidence of neurodegenerative diseases and effects on peripheral nerves and neurodevelopment. However, research to support non-neurological effects such as respiratory symptoms, increased cancer risk, endocrine disruption, cardiac issues, chronic fatigue and infertility, was limited.
Conclusion: Chronic organophosphate exposure was found to affect four of the five areas of described neurological effects in the literature. The a large proportion of the research in this area was not methodologically strong therefore few recommendations can be conclusively drawn. Future research is warranted to investigate the non-neurological effects of chronic exposure to ensure the occupational risks of low level chronic exposure are clearly communicated to farmers and farmworkers.
Implications for Rural Health: This review adds further evidence regarding neurological effects of chronic organophosphate exposure, which needs to be considered for regulation of organophosphates specifically for farmers.