A systematic review of the influence of occupational organophosphate pesticides exposure on neurological impairment

Abstract

ObjectiveThe aim of this study was to conduct a systematic review of the published literature and to estimate whether or not there is a causal relationship between occupational exposure to organophosphate pesticides (OPs) and either neurological impairment or depressive symptoms.Data sourcesEMBASE, MEDLINE, Global Health and PsycINFO (1980 to April 2014).SettingObservational studies (cross-sectional, cohort and case–control studies) with exposed and unexposed groups.ParticipantsPeople who occupationally use OPs for more than 1 month and their family.Primary outcomeResults of neurological core test batteries or depressive symptoms such as headaches, anxiety and dizziness.Study appraisal and synthesis methodsAfter an extensive search of various literature databases, one author screened titles and abstracts, searched the relevant publications manually and conducted data extraction. All extracted data from the selected articles were synthesised for analysis. Quality appraisal was conducted using the Newcastle Ottawa Scale.ResultsOf the 1024 articles retrieved by database search, 24 studies that met the inclusion and exclusion criteria were selected for analysis. Of the selected studies, 17 were cross-sectional and the remaining 7 were cohort and nested case–control studies. The geographical areas included in the studies were the USA (10 studies), the UK (4 studies), Africa (4 studies), Asia (3 studies), Europe (2 studies) and South America (1 study). Each of the included studies used different exposure and outcome assessments such as neurological scores and depressive symptoms, making it difficult to compare the results exactly. Most studies showed that exposed groups had poorer results than unexposed groups; however, owing to the inconsistent neurological test batteries, there was not enough pooling evidence to conduct a meta-analysis.ConclusionsThe findings of this literature review indicate that it is necessary to standardise the neurological or neuropsychological test battery and methods of measuring exposure to OPs.

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].…”

Hepatitis B virus infection status and risk of type 2 diabetes mellitus: A meta‐analysis

“…An adapted Newcastle-Ottawa quality assessment scale (NOS) was used to evaluate the methodological quality of the studies according to the selection of participants, comparability of groups and exposure/outcome ascertainment. 12 Each study was evaluated using the NOS point system. When a study included relevant information which could be related with the NOS, 1 point was added.…”

C. eleganspharyngeal pumping provides a whole organism bio-assay to investigate anti-cholinesterase intoxication and antidotes

“…This enzyme is key in terminating the cholinergic transmission that controls 67 neuromuscular junction and important central synapse function (Koelle 1954, Massoulie, Pezzementi 68 et al 1993). This mode of action has led to the development of these compounds for widespread use 69 as pesticides based on the central role of cholinergic transmission in the animal and plant parasitic life 70 cycle (Takahashi and Hashizume 2014). This widespread use of anti-cholinesterases as pesticides has 71 an associated human intoxication issue.…”