Using In Vivo Bioavailability and/or In Vitro Gastrointestinal Bioaccessibility Testing to Adjust Human Exposure to Arsenic from Soil Ingestion

Remedial investigations (RI) conducted on hazardous waste sites should determine (1) the nature and extent of contamination that exists and (2) the extent to which some level of cleanup must be performed to be protective of human health and the environment. The typical RI includes the collection and chemical analyses of site media, including surface and subsurface soils, surface and groundwater, sediment, and biota (plant and animal species). In some instances, air monitoring may be conducted to determine airborne concentrations of contaminants. An integral component of the RI is the development of the Human Health Baseline Risk Assessment. The risk assessment is the foundation upon which site remediation goals are determined and is developed following two fundamental assessments: a toxicity assessment and an exposure assessment to quantify human intake of contaminated media. Subsequently, by measuring the concentration of chemicals detected in site media, the chemical intake dose can then be quantified to complete the exposure assessment. Contamination of soil with arsenic (As), and its potential impact on human and environmental health, is a global issue. Although As occurs naturally in soil, enrichment of soil-As may occur as a result of a variety of anthropogenic processes including, but not limited to, pesticide/herbicide manufacture and use, mining, smelting, and wood preservation. Arsenic has been ranked the most common inorganic contaminant found in the National Priority List of Sites in the United States (ATSDR 2011). Numerous health effects are associated with As exposure (Lien et al. 1999; Mandal and Suzuki 2002; ATSDR 2011). For example, acute inorganic As poisoning consists of burning/dryness of the oral and nasal cavities, gastrointestinal distress, and muscle spasms. Chronic As exposure results in depression, fatigue, disruption of red cell production, and various forms of cancer. Arsenic exposure pathways of concern include consumption of contaminated food and …