The Health and Risk Assessment Program (HRAP) evaluates human exposure to hazardous substances in the environment and makes health-protective recommendations regarding actions needed to reduce potential health risks.
Specifically, HRAP is responsible for:
• providing technical and scientific assistance and consultation to environmental agencies on exposure to hazardous substances,
• evaluating environmental public health risks,
• developing recommendations to reduce risk from exposure,
• informing the community of possible health risks from exposure,
• addressing community health concerns, and
• providing community health education encouraging actions to reduce the risk of exposure.
Our Role in Contaminated Site Investigations
HRAP works closely with the Missouri Department of Natural Resources (MDNR) and the U.S. Environmental Protection Agency (USEPA) and other agencies to ensure public health protection at contaminated sites across the state. Our role in site investigations is to evaluate potential health risks from exposure to hazardous substances in the environment, to make health-protective recommendations regarding actions needed to reduce potential risks, and to educate communities about the possible health effects of exposure to hazardous substances.
HRAP staff perform two related but distinct functions: health assessment and risk assessment:
- Health Assessment - A health assessment is a public document that educates communities by identifying possible harmful exposures and recommending actions needed to protect public health.
- Risk Assessment - A risk assessment is a technical document written for environmental agencies and is used in decision-making for site cleanups and other risk management strategies. Our risk assessment activities include reviewing and commenting on human health risk assessments and other technical and scientific documents pertaining to contaminated sites.
Evaluating Environmental Public Health Risks
HRAP uses data to evaluate potential health risks from exposure to contaminants in the environment:
- Environmental sampling data (air, water, soil, etc.)
- Chemical-specific data (toxicity data, physical properties)
- Human exposure estimates (exposure frequency, duration, etc.)
Our evaluation seeks to answer:
- What contaminants exist and are of potential concern?
- How might people be exposed to the contaminants?
- At what level of exposure are cancer or non-cancer effects possible?
- What are the potential risks and uncertainties?
- How might risks be eliminated or reduced?
Results of our evaluation consider the potential for both cancer and non-cancer effects from exposure:
- For carcinogens, risks are estimated as the probability of an individual developing cancer over a lifetime.
- For non-carcinogens, a threshold level is used below which adverse health effects are not expected to occur.
Results of evaluations are estimates of the potential for adverse effects and a tool for decision-making that provides a scientific and defensible rationale for response actions.
Exposure and Health Effects
The presence of environmental contamination does not necessarily mean that any exposure is occurring. If there is exposure, not all exposures cause harmful effects:
- The “Dose Makes the Poison” is the basic concept of toxicology.
- the toxicity and concentration of the chemical,
- how the chemical enters a person’s body (such as through ingestion, dermal contact, or inhalation), and
- how much, how often, and how long exposure occurs.
- People respond to chemical exposure in different ways. Individual health, sensitivity, age, and other personal factors play a role in whether or how much an individual may be affected by exposure to a contaminant.
Program Facts
Since the early 1980s, HRAP has worked to assess and respond to issues involving human exposure to harmful chemicals in the environment.
- HRAP conducts hundreds of consultations on contaminated sites each year to determine potential public health risks from exposure.
- Of the 78 National Priorities List (NPL) sites in EPA Region 7, 33 (42%) are located in Missouri. Missouri has the 14th highest number of active NPL sites in the country.
- Missouri has a long history of widespread lead mining and associated operations. Sixty of Missouri’s 114 counties are impacted by historical lead mining, and the waste creates major environmental exposure issues across the state. Missouri has 9 lead-contaminated sites on EPA’s NPL as a result of these historical mining operations.
- Missouri is also one of 8 states in the country with active Formerly Utilized Sites Remedial Action Program (FUSRAP) sites. These sites are impacted by radioactive contamination from the World War II and Cold War eras. Four of the 20 active FUSRAP sites are located in Missouri.
Site-Related Public Health Assessments and Consults