Players in the PHA Process

This section describes the different entities and roles of those involved in the PHA process.

ATSDR staff and its cooperative agreement recipients are responsible for conducting the PHA process, for communicating the findings of their evaluations to the public, and for involving the community and responding to community health concerns. The process requires coordinated efforts that may include local/county, state, and federal government agencies; tribal nations; community residents and leaders; and parties responsible for operating and/or cleaning up a particular site. Collaboration among these different partners is a critical component of the PHA process.

ATSDR often uses a multidisciplinary team approach to conduct the PHA process. Early in the process, if appropriate, a site lead will assemble a site team representing various disciplines (as conditions at the site warrant), including health assessors, health communication specialists, community involvement specialists, health educators, physicians, and others.

The experience and expertise of each team member helps to:

  • Coordinate the PHA process activities.
  • Collect relevant data and information.
  • Engage and communicate with the community and other stakeholders.
  • Evaluate the data and health effects to determine conclusions and public health recommendations.
  • Communicate the findings and public health actions to the community, stakeholders, and the general public.
Cooperative Agreement Program

The cooperative agreement program — ATSDR’s Partnership to Promote Local Efforts to Reduce Environmental Exposure (APPLETREE) — may fund state health departments, tribal governments, and U.S. territories to conduct the PHA to evaluate and respond to environmental public health issues.


The site lead coordinates site-related project activities and preparation of written documents. The site lead may give technical help to communities, states, tribes, and other agencies. They also help with environmental justice activities. Different members of the site team will often help write portions of PHA-process related materials (e.g., a health physicist could write a PHA section on radiation effects), with the site lead coordinating the compilation and review of site documents.

The groups listed below are typically part of the PHA process. Also refer to this table for information on the roles of individuals who may be included as part of a site team.

  • Health Assessors. Health assessors are often the leader of the site team, coordinating the PHA process activities, and working with subject matter experts (SMEs) to gather and evaluate data. Health assessors may come from a range of academic backgrounds, including environmental health, engineering, toxicology, industrial hygiene, health physics, and others. Depending on their expertise and background, as well as the particular site issues, health assessors may perform all or most of the PHA process components on their own, or they may consult with others to assist with some aspects of the PHA process. This table lists individuals with various expertise and disciplines who may be on the site team or provide expert consultation to the health assessor during the PHA process. Usually, the health assessors are responsible for writing the document or portions of the document that summarize the findings of the PHA process.
Diverse group of leaders seated around a table collaborating

ATSDR often uses a multidisciplinary team approach to ensure that information is accurate and up to date, identifies and addresses community concerns, and fosters cooperative efforts in implementing recommendations and public health activities.

  • SMEs. During the PHA process, the health assessor might consult with a variety of SMEs in various subject areas. There are SMEs for certain chemicals and topics, such as air, asbestos, lead, soil pica, and vapor intrusion. The mix of SMEs will vary from one site to another and depend on the nature and complexity of site issues. Health assessors should reach out to the Associate Director for Science (ADS) group for coordinating help with the appropriate SMEs for particular site needs. The SMEs needed can also change over the course of the PHA process as more information becomes available; the composition of the site team can also change. For example, a site with underground water contamination might need assistance from a hydrogeologist to analyze the sampling data whereas a health physicist would be involved at sites dealing with radiation hazards.
  • Internal and External Groups. The site team also coordinates and collaborates with several divisions, offices, and agencies at the local, state, and federal level, and with tribal governments. The organizations involved in the PHA process will vary from site to site and will depend on the nature and complexity of site issues.
Man standing and teaching about community engagement strategies

CDC/Dawn Arlotta: photographer: Cade Martin

  • Regional Representatives. Regional representatives are always included on the site team and kept informed of PHA process activities. They serve as liaisons between ATSDR, the EPA, other environmental and health agencies in their region, and the community. Regional representatives are instrumental in the implementation of ATSDR programs in that region. They maintain current and historical knowledge of the sites and issues in their specific region, provide and follow-up on ATSDR recommendations, and sometimes review site-specific information.
  • Local community. The local community often plays an important role in the PHA process. The community generally consists of people who live and work at or around a site. It can include residents, site or facility personnel, members of local action groups, local officials, tribal members, health professionals, local media, and others.Community members are important partners for the PHA process. They can provide ideas and important data to inform the process, such as undocumented site-specific information. They are also a primary audience and beneficiary of the PHA process. As you conduct the process, community members might want to know what the process involves, what they can and cannot expect, what conclusions you reach, and in general how ATSDR and the PHA process can help address their concerns. Community members can also contribute to the communication and distribution of PHA process conclusions and recommendations, and public health messages. The relationship you build with the community through your public engagement and communication activities will influence how much community members trust you and thus, ultimately, how they react to your public health messages.
Woman standing and teaching

CDC/Dawn Arlotta: photographer: Cade Martin

Individuals Who Health Assessors May Include on the Site Team or Consult for Expertise During the PHA Process

This table presents different individuals who might serve on a site team or be consulted by the health assessor during the PHA process. The health assessor could work alone, depending on the complexity of the site and his or her own expertise, but collaboration is highly recommended by bringing in potential team members or consulting with individuals who have expertise in certain areas. All sites are different, and the individuals included on a site team or consulted for their expertise will vary depending on the particular site-specific concerns and issues.

Individuals on a site team
Discipline or Expertise
Primary Role
Involvement in PHA Process
Behavioral Scientist Researches human behavior and its relationship with disease. Develops community-level and site-specific strategies for healthy behaviors to reduce harmful exposures and studies the effectiveness of preventative measures.
  • Designs, analyzes, and evaluates behavioral surveillance systems, public health interventions, and health promotion and communication programs.
  • Uses quantitative and qualitative methods to evaluate the relationship between behavior and disease.
Community Involvement Specialist Coordinates and oversees outreach to provide opportunities for community engagement in the PHA process.
  • Earns and maintains a community’s trust and credibility through open, compassionate, and respectful communications.
  • Helps community members understand the PHA process.
  • Promotes collaboration between ATSDR, communities, and other agencies.
  • Informs and updates communities about ATSDR’s work.
  • Helps communities understand the possible health impact of exposures to hazardous substances (or the lack thereof).
Environmental Health Scientist Evaluates data and conducts investigations to examine whether human exposures to environmental contaminants can result in potential harmful health effects. Makes conclusions about potential impacts to public health associated with environmental exposures, including exposure pathways, sampling data, site-specific information, population characteristics, and contaminant-specific properties.
  • Collects site information to learn about site conditions, the potentially exposed population, and other details to help inform the PHA process.
  • Identifies the pathways through which people may contact site contamination.
  • Examines environmental and biological sampling data collected for a site.
  • Evaluates whether contaminants detected at a site are present at concentrations that could potentially result in harmful health effects for exposed populations.
Epidemiologist Studies the distribution and determinants of disease in a particular population.
  • Evaluates health outcome data.
  • Evaluates appropriateness of scientific studies to evaluate during the PHA process.
Expert in Tribal Affairs Provides expertise to the site team on American Indian and Alaska Native (AI/AN) government structures, relationships to the U.S. government, and unique cultural aspects. Works with AI/AN populations to identify and evaluate environmental health concerns and empower individual tribes to make informed decisions that benefit their communities.
  • Promotes and supports the government-to-government trust relationship between NCEH/ATSDR and AI/AN tribes.
  • Builds relationships with AI/AN tribes; federal, state, and local agencies; national tribal organizations; and others.
  • Provides education and training to develop environmental health knowledge and skills.
Geographic Information System (GIS) Scientist Applies science and GIS (a mapping system to collect, store, manipulate, analyze, and display data) technology to manage geographic relationships and integrate information.
  • Works with health assessors to develop geospatial analyses and maps that enable ATSDR scientists to better understand interrelated environmental, socio-demographic, and behavioral issues affecting potential exposures at hazardous waste sites.
Health Communication Specialist Provides consultation and expertise to develop and implement priorities, strategies, and practices for communicating with various audiences. Analyzes and applies communication strategies to inform and influence community members’ decisions that enhance health.
  • Develops and manages communication strategies for the general public and other audiences.
  • Analyzes community characteristics, concerns, needs, and health issues to inform communication strategies, messages, and talking points.
  • Develops and promotes plain language and clear communication messages and products.
  • Ensures consistent messaging on contaminants across different sites.
  • Supports development and issuance of media releases, press briefings, and ATSDR website content.
  • Provides training to site team members on speaking with the media.
Health Educator Provides guidance on health education programs, projects, and activities. Specifies appropriate instructional strategies and media to use for reaching desired populations. Proposes, develops, and refines programs,  and establishes methods for monitoring public health programs.
  • Coordinates and oversees all PHA process-related health education activities.
  • Provides community environmental health education and/or health care provider education on types of contaminant exposures, exposure routes and pathways, health effects, treatment options, and methods to prevent and minimize environmental exposures.
Health Physicist Evaluates and interpret data on radiological agents in food, human tissue, and the environment.
  • Advises on methods for addressing radiation hazards and health effects associated with possible exposures to radioactive and nuclear materials.
  • Makes public health determinations and recommendations to protect the health of affected communities.
Hydrogeologist Evaluates groundwater characteristics (e.g., depth, direction, type of flow) to see how hydrogeologic conditions might influence groundwater movement and the possibility of contaminants reaching people. Can  research the location, size, and movement of underground water reservoirs and the impact of contamination on these waters. Often uses advanced computer modeling programs and imaging technology to evaluate groundwater flow and to map groundwater reservoirs.
  • Makes recommendations to prevent or remediate groundwater contamination of hazardous waste sites.
  • Reviews, interprets, and provides expert advice on hydrogeological studies.
  • Designs and leads vapor intrusion studies and investigations.
  • Reviews and interprets complicated geophysical data sets.
Industrial Hygienist Evaluates factors related to industrial releases that can cause illness, impair health, or affect the well-being of potentially exposed community members.
  • Prepares consultations, conducts surveillance, and performs environmental testing.
  • Helps interpret sampling data results.
  • Recommends strategies to prevent exposure.
  • Provides information to health care providers investigating possible toxic exposures.
Physician Investigates health issues related to environmental exposures and recommends strategies to reduce and stop exposures.
  • Helps train health care providers on how to evaluate community members who have potentially been exposed to hazardous substances.
  • Provides education and care instruction to community members affected or concerned about environmental exposures.
  • Helps interpret and provides recommendations on scientific literature and environmental medicine studies.
  • Speaks with community members about their health concerns and exposure pathways in the community.
Statistician Collects, reviews, summarizes, and interprets data or information. Examines these data to determine whether differences between study groups are meaningful.
  • Performs statistical analyses on collected data for use during the PHA process.
  • Develops sample and survey designs to conduct research in communities affected by hazardous substances.
  • Evaluates if methods used in health research are valid and reliable, including for information analyzed during the PHA process.
Toxicologist Studies the health effects from natural and human-made toxicants in living organisms. Evaluates health effects that might occur from exposure to site-related toxic chemicals.
  • Provides subject matter expertise to site-specific activities, including chemical-specific consultations.
  • Helps interpret toxicological studies.
  • Provides guidance on using appropriate dose-response information when examining site-specific doses and concentrations.
  • Offers guidance on helping determine whether non-cancer and cancer effects are possible based on site-related estimated exposures.
Page last reviewed: August 4, 2022