By: Deborah E. Peters, LPG
This document was written in 1997 while Deborah Peters was working with the Indiana Department of Environmental Management on the development of the RISC (Risk Integrated System of Closure) program.
Risk and risk management has a different meaning to most everyone. From an occupational viewpoint, risk described by a police officer might involve entering a bank in the midst of a robbery without appropriate back-up. A fire fighter may view a high risk situation as going into a burning building without knowing what type of fire fighting gear is required. A physician may describe a high risk as performing a new surgical procedure that has life-threatening implications to his/her patient.
Risk in some form is present in everyone’s day-to-day activities. Whether it’s risk associated with transportation, occupational risk, risk associated with consumption of food and beverages, the residential area where one resides, and recreational activities all pose their own type of risk. Obviously, individuals who drive motorcycles without a helmet, smoke cigarettes and consume alcoholic beverages, work at hazardous waste sites, live near a contaminated site, and sky dive and scuba dive for recreational purposes elects to have considerably high level of risk.
What about the risk posed to human health and the environment as a result of contaminated soil, groundwater and air? This can be another form of risk that no one would elect and a risk that is not as easy to control. The Indiana Department of Environmental Management (IDEM) is the government agency tasked with regulating and enforcing environmental law designed to protect human health and the environment. IDEM is developing a consistent risk management policy designed to help address risk caused as a result of contaminated site. This policy will be known as the Risk Integrated System of Cleanups (RISC). RISC is designed to assist property owners and the IDEM staff to screen, prioritize and address all contaminated sites based on the threat each site poses to human health and the environment. This RISC approach will consist of a thorough site evaluation which will identify all contaminated media, identify who is at risk (receptors) and establish institutional controls while determining whether some form of site remediation should be implemented.
The RISC process will evaluate human health risk from an occupational, residential and recreational standpoint based on how the exposure to the contamination might occur. For example, will one work at hazardous waste sites, live in a neighborhood near a contaminated site, work for or live near an industrial site, and/or swim or consume fish from contaminated waters. A good risk assessor will identify all possible exposures to the contaminant, although the assessor will discuss the uncertainties involved in the overall risk estimates and present them in the proper perspective.
The risk posed to human health from an occupational standpoint will depend on the type of contamination present and the concentration. To a construction worker excavating contaminated soil, it is extremely important to determine what the soil is contaminated with and the contaminant’s concentration level.
The evaluation of this contaminated site must be complete and thorough in order to determine if the impacted soil will pose a threat to the construction worker and educate and protect the construction worker on the hazards that each contaminate may pose. For example, will the contaminate be a problem for the construction worker by skin contact? Or will the contaminate be a problem for the construction worker through inhalation, such as asbestos fibers, and/or high contaminate vapors? It is important that the construction worker be aware of what adverse health effects may be/are associated with those contaminates.
Evaluating human health risk based on a recreational scenario means that all medias need to be evaluated, soil, water and air. If a contaminated site is in a neighborhood, then it is extremely important to ensure that the residents are not being exposed to any contaminates. This is completed through determining whether the residents are drinking and/or showering in contaminated water, inhaling contaminate vapors entering the home via basements and/or foundations and/or in the shower. Inhalation of contaminated dust particles may be another concern. What if the home owner has a garden? It is important to ensure that the garden soil is not contaminated and that residents are not consuming fruits and vegetables grown in contaminated soil. Finally, it is important that children are not exposed to contaminated soil through skin contact, accidental ingestion and inhalation of soil particles.
Evaluating human health risk based on a recreational exposure addresses individuals who may be swimming in contaminated water, accidental ingestion of contaminated water, and ingestion of impacted fish. The hunter who may consume impacted game should be considered. It should be noted that individuals have different tolerances and sensitivities to different substances, therefore the risk assessor evaluates the contamination based on the most sensitive receptor. RISC will evaluate environmental impacts as well as human health. These environmentally sensitive areas will include wetlands, state parks, surface waters, wellhead protection areas, sole source aquifers, other sensitive areas, and state and federally endangered species.
Is it possible to eliminate all human health risk concerns based on contaminated sites? Obviously it would be great to answer YES! Unless all natural environmental disasters, such as tornadoes, earthquakes, and fires caused by lightning can be controlled, it seems improbable that all human health risk can be minimized. Secondly, unless you are an individual who lives in a n environmentally controlled bubble you will be exposed to some type of risk in normal day to day activities.
There are ways to manage most risk associated with contaminated sites. One solution to managing risk is through proper education and environmental awareness programs that can be presented to both the regulated community and the general public. Environmental enrichment programs such as communities involved in “Brownfields” sites is another good tool to risk management. Finally, pollution reduction programs that address solid and hazardous waste management, air pollution regulations, and the “Clean Water Act” are programs enacted to assist protect natural resources and manage risk.
Deborah E. Peters, CPG is the principal hydrogeologist and president of Quality Environmental Professionals, Inc. (QEPI). Peters expertise include risk management, subsurface investigations and interpretation, groundwater modeling, process safety management and the establishment of environmental databases. Peters has been actively involved in the development of the Risk Management Policy for IDEM.