Fall NEARC 2024

Amyotrophic Lateral Sclerosis (ALS) is a debilitating neurodegenerative condition impacting the central nervous system. Although it is widely acknowledged that ALS stems from interactions between genetic and environmental factors, the exact etiology of ALS is still unclear and has catalyzed a global research pursuit. Our research quantifies the correlation between environmental nickel exposure and ALS incidence in Ohio utilizing GIS methods within ArcGIS Pro. We acquired AERMOD atmospheric dispersion and pollution data from the EPA containing annual average chemical concentrations across the US in CSV files. Nickel concentrations from Media 1 (point sources) and Media 2 (non-point sources) were aggregated annually and converted into vector shape files. The data is then transformed into raster format, adjusting chemical values for integer operations. We ran logistic regression to calculate Odds Ratios for ALS and nickel exposure, using novel methods to consider migration history prior to diagnosis and population density as confounding factors. A moving window analysis is used to iteratively examine the influence of population density on the spatial distribution of ALS cases. For migration history, we employed an expanding window to read the exposure value of subjects at diagnosis and years prior, resulting in nickel and nickel compound exposure data that spanned over twenty-five years of subjects’ migration history. Our analysis expands on previous studies by accounting for migration history and forgoing the assumption that subjects reside in one location indefinitely. Surprisingly, some of our results indicate that pure nickel and nickel compounds have significant protective effects against ALS development. This effect is more prevalent in rural areas than urban ones and is largely consistent across different windows of migration history. Our findings warrant further investigation into the physiological and geospatial connections between nickel and ALS.