Letter Health Consultation: Sparta Aquifer Vulnerability Study/Health Implications of Heavy Metals Contamination in Locust Bayou Private Wells (Phase II), Locust Bayou, Calhoun County, Arkansas, June 17, 2008.

摘要

Exposure to contaminants of concern is determined by examining human exposure pathways. An exposure pathway has five parts: (1) A source of contamination (e.g., industrial facilities utilizing hazardous materials), (2) An environmental medium such as water, soil, or air that can hold or move the contamination, (3) A point at which people come in contact with a contaminated medium (e.g., private residential well water), (4) An exposure route, such as drinking well water from the same aquifer that is close to the industrial facility, and (5) A population who could come in contact with the contaminants. An exposure pathway is eliminated if at least one of the five parts is missing and will not occur in the future. For a completed pathway, all five parts must exist and exposure to a contaminant must have occurred, is occurring, or will occur. For this evaluation, a complete pathway has been identified. Because the private residential wells draw from the same shallow aquifer that is being monitored by the EPA for potential contamination surrounding the former Shumaker property, the source exists for the same compounds found in the EPA groundwater monitoring study to be detected in the private residential well water, and therefore consumed by an individual on a daily basis.