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Olfactory Function in Farmworkers: Do Pesticides Reduce Their Sense of Smell Over Time?

Olfactory Function in Farmworkers: Do Pesticides Reduce Their Sense of Smell Over Time?

farm worker applying pesticides to field


[Editor’s Note: This issue’s Environmental and Occupational Health section features three articles summarizing recent research reports pertinent to the health of farmworkers and migrant workers.]

Quandt SA, Walker FO, Talton JW, Chen H, Arcury TA. Olfactory Function in Latino Farmworkers Over 2 Years: Longitudinal Exploration of Subclinical Neurological Effects of Pesticide Exposure. J Occup Environ Med. 2017 Dec;59(12):1148-1152. doi: 10.1097/JOM.0000000000001123

Over the course of two years, male Latino farmworkers exposed to pesticides maintained significantly reduced olfactory function, compared to the control group of male Latino workers from other industries without pesticide exposure. The findings have been published in the most recent issue of the Journal of Occupational and Environmental Medicine.

Low-level, long-term pesticide exposure has been proven to increase the risk of neurodegenerative diseases like Parkinson’s disease. The authors of this study set out to determine if such low dose and frequent occupational pesticide exposure results in olfactory function decline over time, and to deduce if any differences between exposed and non-exposed farmworkers in olfactory function persist over time.

The authors recognize the challenges of studying the impact of pesticides on farmworker health, particularly in the development of neurological diseases. Many farmworkers migrate for work or begin work in another industry before researchers can conclude long-term studies. “For such populations, it may be useful to identify subclinical disease indicators that precede the development of neurodegenerative diseases. Loss of olfactory function has been consistently identified as one such indicator, occurring early in the disease process before other symptoms occur,” the authors noted.

The researchers recruited 158 Latino farmworkers and 118 Latino non-farmworkers in North Carolina. Over the course of two years, the participants completed questionnaires and attended a clinic for the collection of clinical measures and the testing of olfactory function,which included both identification and detection tests.

The results showed that, adjusted for age and smoking, farmworkers had significantly and consistently poorer olfactory function than non-farmworkers, but that over the course of the two years, despite ongoing low-level exposure to pesticides, farmworker olfactory function did not decline further.

“This result is somewhat unexpected,” the authors admitted. They conclude that “it is possible that, while pesticides can precipitate initial injury to the olfactory nerve, other factors determine whether there is further neurodegenerative progression. Additional research is needed to confirm these findings in other worker populations and to determine factors that lead to neurodegenerative diseases in pesticide-exposed populations.”


MCN Streamline Fall 2018


Read this article in the Winter 2018 issue of Streamline here!

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