Parkinson's Disease Is Predominantly an Environmental Disease

Abstract

Parkinson's disease is the world's fastest growing brain disorder, and exposure to environmental toxicants is the principal reason. In this paper, we consider alternative, but unsatisfactory, explanations for its rise, including improved diagnostic skills, aging populations, and genetic causes. We then detail three environmental toxicants that are likely among the main causes of Parkinson's disease- certain pesticides, the solvent trichloroethylene, and air pollution. All three environmental toxicants are ubiquitous, many affect mitochondrial functioning, and all can access humans via various routes, including inhalation and ingestion. We reach the hopeful conclusion that most of Parkinson's disease is thus preventable and that we can help to create a world where Parkinson's disease is increasingly rare.

Keywords: Parkinson disease; genetics; indoor air pollution; mitochondria; pesticides; primary prevention; solvents; tetrachloroethylene; trichloroethylene; water pollution.

Fig. 1

A) Incidence of Parkinson’s disease by age and sex in the United Kingdom, 2017 [16]. B) Incidence of lung cancer by age and sex in the United Kingdom, 2016–2018 [17].

Fig. 2

A) Incidence of Parkinson’s disease in the U.S., 2012 [49]. B) Estimated annual use of paraquat in the U.S., 1992 [50]. Map of release of trichloroethylene (orange) and perchloroethylene (in blue) in the U.S, 1987. Map courtesy of Meghan Pawlik, University Rochester, based on data from the Toxic Release Inventory from the U.S. Environmental Protection Agency. D) Map of particulate matter smaller than 2.5 microns in the U.S., 2006 [51].