Risk Factors for Brain Health in Agricultural Work: A Systematic Review

Abstract

Certain exposures related to agricultural work have been associated with neurological disorders. To date, few studies have included brain health measurements to link specific risk factors with possible neural mechanisms. Moreover, a synthesis of agricultural risk factors associated with poorer brain health outcomes is missing. In this systematic review, we identified 106 articles using keywords related to agriculture, occupational exposure, and the brain. We identified seven major risk factors: non-specific factors that are associated with agricultural work itself, toluene, pesticides, heavy metal or dust exposure, work with farm animals, and nicotine exposure from plants. Of these, pesticides are the most highly studied. The majority of qualifying studies were epidemiological studies. Nigral striatal regions were the most well studied brain area impacted. Of the three human neuroimaging studies we found, two focused on functional networks and the third focused on gray matter. We identified two major directions for future studies that will help inform preventative strategies for brain health in vulnerable agricultural workers: (1) the effects of moderators such as type of work, sex, migrant status, race, and age; and (2) more comprehensive brain imaging studies, both observational and experimental, involving several imaging techniques.

Mortality from nervous system diseases and cancer in agriculture workers: a case-control study in Italy

“…In a review by Nandipati and Litvan [37], the authors addressed that among the different pesticides, rotenone, paraquat, and organochlorines have been well-documented in human epidemiological studies to be associated with Parkinson's diseases, while organophosphates, pyrethroids, and polychlorinated biphenyls require further study. In a more recent systematic review, Sturm et al [35] examined 22 studies about the relationship between agricultural work and Parkinson's disease or Parkinsonism but they did not all agree on the presence of an association. Positive associations were found in studies carried out in France [41], Norway [53], US [54] and Spain [36].…”

“…In the recent and past literature, exposure to agriculture agents like pesticides has also been associated with neurodegenerative diseases [31,[35][36][37][38][39][40][41]. Parkinson's disease, amyotrophic lateral sclerosis (ALS) and Alzheimer's disease are the most common neurodegenerative disorders, that has been related with exposure to pesticide with an increase of risk by at least 50% [42][43][44].…”

“…More recent studies involved other health effects such as epilepsy [38], tremor [39] and neurobehavioral, neuromotor, and neurocognitive effects [40]. Not all studies agreed on the association between agricultural work and increased risk of brain disease [35,45,46]. Misclassi cation and inadequate response rates are considered as possible explanations for the non-association observed in some studies [47,48].…”

Effect of Structured Teaching Programme on Reduction of Level of Stress among Agricultural Workers in Selected Area at Puducherry

“…Agriculture and farming shall encompass soil cultivation, dairying, forestry, and the harvesting of any agricultural or horticultural common areas. Agricultural workers have historically been the most overlooked and exploited group of workers [2,3]. The farm worker who spends the day between slush and muck, who works now with a half-satisfied appetite, and who knows no rest in storms or sunshine [4].…”

Research of Pesticide Metabolites in Human Brain Tumor Tissues by Chemometrics-Based Gas Chromatography–Mass Spectrometry Analysis for a Hypothetical Correlation between Pesticide Exposure and Risk Factor of Central Nervous System Tumors

“…The central nervous system (CNS) is the main target of acute toxic action by diverse insecticides including organophosphates (OPs), carbamates (CARs), organochlorines (OCs), fungicides, and fumigants. ,, Various epidemiologic studies have been investigated to assess pesticide’s human health risk with a special focus on agricultural settings . Farmers were revealed to be at a greater risk for brain cancer as well as psychiatric and neurological disorders compared to other professions. − Parental occupation and home proximity to treated fields have also been used to assess pesticide exposures among children since pesticides may affect neurodevelopment …”