Risk Assessment: Environmental Health Depends upon It

Article excerpt

Each day, decisions are made that affect the environmental health and well being of communities. Sound environmental decisions are usually founded on three basic tools that provide information on environmental risk: the assessment, communication, and management of risks.

Risk assessment measures the amount and level of the pollutants usually in scientific or technical terms. In turn, risk communication uses the scientific information gathered from assessing the environmental hazard and makes it available and understandable to others within local government, the media, and stakeholders, such as residents, private businesses, and state and federal government agencies that are involved or have an interest in the environmental issue.

Risk management uses these two components, risk assessment and risk communication, to see how an environmental problem can be addressed with available resources like staffing, materials, and funding. This is done in accordance with the laws and stipulations of the local, state, federal, and corporate regulatory bodies devoted to the overall sustenance or enhancement of human health, nature, and all living things in the environment.

This article defines the three types of risk assessment, explains the general misperceptions held by many local government managers of the data retrieved from risk assessments, and discusses how some localities are using this tool to tackle environmental risks and to aid in the decision-making process for policy development.

Risk Definition

Risk assessment is one of the key methods used to determine the level of pollutants in the environment and the degree to which populations are exposed to those pollutants.

"Risk assessment," as defined by the National Research Council (NRC) and the United States Environmental Protection Agency (EPA), is the identification of potential adverse health effects on humans or ecosystems resulting from exposure to environmental health hazards. The three types of risk assessments are human health, ecological, and comparative--three approaches that involve similar evaluation steps but that are used to identify different variables.

Human health exposure. Assessment of a risk to human health entails four steps: (1) hazard identification, (2) dose-response, (3) exposure, and (4) risk characterization. The first step, hazard identification, determines whether an exposure to a pollutant can cause adverse health effects, which can range from runny eyes or asthma to cancer and birth defects. From a scientific perspective, cancer and birth defects are the primary indicators of adverse health effects.

In the second step, that of dose-response, the relationship is characterized between the level of exposure (or dose) and the probability of occurrence of adverse health effects. Step three, exposure, determines the intensity and frequency of exposure to a pollutant suffered by humans and the environment, while step four, risk characterization, combines the assessments of response and exposure under various conditions and uses them to estimate the level of potential risk to humans and the environment.

In short, the information gained through hazard identification is used to develop exposure and toxicity assessments. In step four, risk characterization, the researcher summarizes and combines the results of the toxicity and exposure steps into defined environmental risks that can be expressed in quantitative or qualitative terms for future evaluation by environmental risk managers.

Ecological risk assessment. This kind of assessment looks at the effects of one or more harmful components that may injure either a few individuals of a certain species or an entire ecosystem. These harmful ecological components or stressors can be chemical, physical, or biological. Ecological risk assessment simply evaluates the likelihood that ecological effects may occur or are occurring. …