Pesticide Use and Age-Related Macular Degeneration in the Agricultural Health Study

Abstract

Background:Age-related macular degeneration (AMD) is a leading cause of blindness in developed countries. Few studies have investigated its relationship to environmental neurotoxicants. In previous cross-sectional studies, we found an association between pesticide use and self-reported retinal degeneration.Objective:We evaluated the association of pesticide use with physician-confirmed incident AMD.Methods:The Agricultural Health Study (AHS) is a prospective cohort of pesticide applicators and their spouses enrolled from 1993–1997 in Iowa and North Carolina. Cohort members reported lifetime use of 50 specific pesticides at enrollment. Self-reports of incident AMD during follow-up through 2007 were confirmed by reports from participants’ physicians and by independent evaluation of retinal photographs provided by the physicians. Confirmed cases (n=161) were compared with AHS cohort members without AMD (n=39,108). We estimated odds ratios (ORs) and 95% confidence intervals (CIs) by logistic regression with adjustment for age, gender, and smoking.Results:AMD was associated with ever use of organochlorine [OR=2.7 (95% CI: 1.8, 4.0)] and organophosphate [OR=2.0 (95% CI: 1.3, 3.0)] insecticides and phenoxyacetate herbicides [OR=1.9 (95% CI: 1.2, 2.8)]. Specific pesticides consistently associated with AMD included chlordane, dichlorodiphenyltrichloroethane (DDT), malathion, and captan; others with notable but slightly less consistent associations were heptachlor, diazinon, phorate, 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), and 2,4-dichlorophenoxyacetic acid (2,4-D). Results were similar for men and women. Some specific pesticides were associated with both early- and late-stage AMD, but others were associated with only one stage.Conclusions:Exposures to specific pesticides may be modifiable risk factors for AMD. https://doi.org/10.1289/EHP793

Dietary, environmental, and genetic risk factors of Extensive Macular Atrophy with Pseudodrusen, a severe bilateral macular atrophy of middle-aged patients

“…The present study highlighted a possible toxic mechanism in EMAP with a higher incidence observed in regions with industrialized or farming activities, and a toxic exposure during professional life. In AMD, fungicides may increase the risk of retinal degeneration based on the Agricultural Health Study of farm families from Iowa and North Carolina (1993–1997) 18 , 19 . The role of long-term/low-dose exposure to pesticides (organophosphates, paraquat) is well documented in Parkinson disease, which is the consequence of a degeneration preferentially affecting the dopamine-synthesizing neurons of the nigrostriatal neuronal pathway 20 – 23 .…”

Urinary concentrations and profiles of organophosphate and pyrethroid pesticide metabolites and phenoxyacid herbicides in populations in eight countries

“…Several epidemiologic studies have shown that chronic, low-dose exposure to OPs and PYRs was associated with neurological outcomes (e.g., neurodevelopment in children, Parkinson’s disease), endocrine-disrupting effects (e.g., metabolic syndrome, obesity, diabetes), and reproductive effects (e.g., reduced semen quality, reduced gestational age, reduced birth weight) (Furlong et al, 2014; González-Alzaga et al, 2014; Saillenfait et al, 2015; Coker et al, 2018). Exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), the most commonly used PAs, is linked to wheeze, non-Hodgkin’s lymphoma, soft-tissue sarcoma, and age-related macular degeneration (Jayakody et al, 2015; Hoppin et al, 2017; Montgomery et al, 2017).…”

Prenatal exposure to the herbicide 2,4-D is associated with deficits in auditory processing during infancy

“…The occupational literature regarding visual or auditory effects of 2,4-D is also scarce. One study found that use of phenoxyacetate herbicides, including 2,4-D, was associated with higher odds of age-related macular degeneration in farmers in the Agricultural Health Study (U.S.) (Montgomery et al, 2017). To our knowledge, no auditory effects of 2,4-D exposure have been reported in farmers or pesticide applicators.…”