Further to the editorial on October 9th deprecating the use of chlorpyrifos that has detrimental effects on the development of fetal and neonatal brain development, Dr. Martin Hugh-Jones Emeritus Professor, Louisiana State University, forwarded a reference to an epidemiologic study on Parkinson’s disease in Louisiana covering 1999 through 2012.  Martin is an eminent epidemiologist now affiliated in retirement with the Department of Environmental Sciences, College of the Coast and Environment at LSU in Baton Rouge. 

Together with colleagues at the Louisiana Geologic Survey, Hugh-Jones investigated the prevalence of Parkinson’s disease based on hospital data and correlated the findings with local agricultural crops, pesticide use, and aquifer recharge.  By mapping cases against known crop distributions and pesticides using zip code address locations and census data it was possible to produce a series of maps overlaying the prevalence of Parkinson’s disease and agricultural use.  The areas affected by Parkinson’s disease were associated with commercial forests, woodlands, and pastures where arbor-pastoral pesticides including 2,4-D, chlorpyrifos, and paraquat are used.  The study clearly indicated a higher risk of Parkinson’s disease in areas applying the three agricultural pesticides including chlorpyrifos, suggesting that the deleterious effect is not limited to the immature nervous system.

Hugh-Jones, M. E. et al. Parkinson’s Disease in Louisiana, 1999-2012: Based on Hospital Primary Discharge Diagnosis, Incidence, and Risk in Relation to Local Agricultural Crops, Pesticides, and Aquifer Recharge. Int.J.Environ.Res.and Public Health. 171584;doi.org/10.3390/ijerph17051584 (2020).