Environmental copper: Its dynamics and human exposure issues

This article provides an overview of the environmental patterns and dynamic s of copper from the perspective of issues that affect our ability to exami ne current human exposures. It presents selected summary information on the levels of copper found in various media and exposure pathways from a varie ty of information sources, and discusses the breadth and the limitations of this information. The analysis presented focuses on the ability to provide quantitative values for both external metrics of exposures (microenvironme ntal levels) and internal biological markers of exposure. The status of the current information on environmental copper is placed within a conceptual framework that can be used to identify data gaps, assess the utility of cur rent biological markers of exposure, and examine the need for systematic an d consistent data-gathering studies to improve our ability to complete expo sure assessments. A primary concern is the exposure to copper through potab le water supplies; this is considered within a framework that examines copp er levels and distribution in food, soil, air and sediments, as well as the levels found in biological media such as urine, blood, and hair. An existi ng water consumption model for copper and associated exposure factors is br iefly discussed. This type of model will eventually be valuable within a to tal exposure analysis modeling framework that can consider and prioritize e xposures from multiple routes and differentiate levels of concern for both excesses and deficiencies in exposure, an important issue, since copper is an essential nutrient. Finally, this review attempts to examine the needs f or better information using as a basis the concerns briefly mentioned in th e recent NRC report "Copper in Drinking Water" (National Research Council, 2000).