The recoverable reserves of coal in Illinois amount to 101.6 billion metric tons, which is third largest in the United States. Mining operations in the Edwardsville area began in 1857 and ceased in the 1960s. The mining operations and rail transport released large amounts of contaminants into the surrounding soil. At the end of the mining era, the former railways were converted into paved recreational trails.

A strong correlation between heavy metal contamination, railway transport and coal mining sites has been found in previous studies. This study was done to determine if there are still high levels of heavy metals along the current recreational trails. Soil tends to work as a natural trap for heavy metals and decrease their bio-availability. The release of toxic heavy metals and metalloids into the surrounding environment can expose individuals to a variety of potential health hazards. In this study, the heavy metals of As, Pb, Ni, Zn, and Cu within soil samples were examined. ArcGIS was used to create map of area and locate sampling sites. Fifty-six samples were taken from seven sites at depths of 5 and 15 cm. A modified EPA 3050B digestion method followed by inductively-coupled mass spectrometry was used to obtain concentration values.

Anova, Manova, and Principle Component Analysis were used in to interpret the data. One site was found to have elevated levels of all heavy metals compared to all other sites. A second site had the highest levels of As and elevated levels of Pb and Zn. The mean concentrations across all sites ranged from As (22-44), Cu (40-974), Ni (21-74), Pb (34-246), Zn (114-2559). Overall Manova shows that the entire complex of contamination varies at the level of the site, but not at location or location within the site. Depth of the sample and the distance from the trail were also not significant factors.

The average heavy metal levels found in this study site were lower than US EPA SSL, IEPA SSL, and NYS DEC values, with As being the only exception. This being said, As does fall into the US EPA's acceptable background range of arsenic in soil which is a separate standard from Soil Screen Levels. Based on this study, the sites, locations within sites and even "hotspots" are not cause for alarm.