Prevalence rates of neurodegenerative diseases versus human exposures to heavy metals across the United States

Melanie Engstrom Newell; Ayesha Babbrah; Anumitha Aravindan; Raj Rathnam; Rya Kiernan; Erin M Driver; Devin A Bowes; Rolf U Halden

doi:10.1016/j.scitotenv.2024.172260

Prevalence rates of neurodegenerative diseases versus human exposures to heavy metals across the United States

Sci Total Environ. 2024 Jun 10:928:172260. doi: 10.1016/j.scitotenv.2024.172260. Epub 2024 Apr 5.

Authors

Melanie Engstrom Newell¹, Ayesha Babbrah², Anumitha Aravindan³, Raj Rathnam², Rya Kiernan³, Erin M Driver³, Devin A Bowes³, Rolf U Halden⁴

Affiliations

¹ Arizona State University, USA; Biodesign Center for Environmental Health Engineering, USA; School for Engineering of Matter, Transport and Energy, USA.
² Arizona State University, USA; Biodesign Center for Environmental Health Engineering, USA; Barrett The Honors College, USA.
³ Arizona State University, USA; Biodesign Center for Environmental Health Engineering, USA.
⁴ Arizona State University, USA; Biodesign Center for Environmental Health Engineering, USA; School for Engineering of Matter, Transport and Energy, USA; Barrett The Honors College, USA; School of Sustainable Engineering and the Built Environment, USA; OneWaterOneHealth, USA; Correspoding author at: Biodesign Institute Building B, 1001 S McAllister Ave B249, Tempe, AZ, USA 85287.. Electronic address: rolf.halden@asu.edu.

PMID: 38583622
DOI: 10.1016/j.scitotenv.2024.172260

Abstract

Novel means are needed to identify individuals and subpopulations susceptible to and afflicted by neurodegenerative diseases (NDDs). This study aimed to utilize geographic distribution of heavy metal sources and sinks to investigate a potential human health risk of developing NDDs. Known or hypothesized environmental factors driving disease prevalence of Alzheimer's Disease (AD), Parkinson's Disease (PD), and amyotrophic lateral sclerosis (ALS) are heavy metals, including arsenic (As), cadmium (Cd), manganese (Mn) and mercury (Hg). Lead (Pb) has been associated with AD and ALS. Analyzable mediums of human exposure to heavy metals (i.e., toxic metals and metalloids), or proxies thereof, include infant blood, topsoil, sewage sludge, and well water. U.S. concentrations of heavy metals in topsoil, sewage sludge, well water, and infant blood were mapped and compared to prevalence rates of major NDDs. Data from federal and state agencies (i.e., CDC, EPA, and the US Geological Survey) on heavy metal concentrations, age distribution, and NDD prevalence rates were geographically represented and statistically analyzed to quantify possible correlations. Aside from an expected significant association between NDD prevalence and age (p < 0.0001), we found significant associations between the prevalence of the sum of three major NDDs with: Pb in topsoil (p = 0.0433); Cd (p < 0.0001) and Pb (p < 0.0001) in sewage sludge; Pb in infant blood (p < 0.0001). Concentrations in sewage sludge of Cd and Pb were significantly correlated with NDD prevalence rates with an odds ratio of 2.91 (2.04, 4.225 95%CI) and 4.084 (3.14, 5.312 95%CI), respectively. The presence of toxic metals in the U.S. environment in multiple matrices, including sewage sludge, was found to be significantly associated with NDD prevalence. This is the first use of sewage sludge as an environmental proxy matrix to infer risk of developing NDDs.

Keywords: Exposure; Heavy metals; Mapping; Neurodegenerative disease; Prevalence; Sewage sludge.

MeSH terms

Environmental Exposure* / statistics & numerical data
Environmental Monitoring
Humans
Metals, Heavy* / analysis
Neurodegenerative Diseases* / chemically induced
Neurodegenerative Diseases* / epidemiology
Prevalence
United States / epidemiology

Substances

Metals, Heavy