NEHA November 2022 Journal of Environmental Health

40 Volume 85 • Number 4 A D VANC EME N T O F T H E PRACTICE  D I RECT FROM ATSDR Background The Agency for Toxic Substances and Disease Registry (ATSDR) protects communities from harmful health e ects related to exposure to natural and humanmade hazardous substances. ATSDR works closely with tribal agencies, the ATSDR Partnership to Promote Localized E orts to Reduce Environmental Exposure (APPLETREE state partners), and other stakeholders to conduct public health assessments (PHAs). PHAs investigate exposures to environmental contaminants, evaluate potential health e ects, and develop public health action plans to prevent and reduce these exposures in communities. During the PHA process, ATSDR and state partners review various types of data and information to determine exposure and potential for harmful health e ects in communities living near hazardous sites (ATSDR, 2022). The scientific evaluation includes several important steps: • screening contaminants for further evaluation, • estimating exposure doses and concentrations, and • calculating hazard quotients and cancer risk. Conducting scientific evaluation and assessing public health impacts have become increasingly challenging due to complex sites, multiple exposure routes, multiple chemical exposures, emerging contaminants, and evolving knowledge of chemicals and their toxicities. To improve the scientific quality and consistency of PHA work conducted by health assessors at ATSDR and state health departments, ATSDR has developed a webbased application called the Public Health Assessment Site Tool (PHAST; Figure 1). Public Health Assessment Site Tool Overview PHAST helps health assessors evaluate exposure to harmful chemicals at hazardous waste sites by following the approach described in ATSDR’s Public Health Assessment Guidance Manual (ATSDR, 2022; Ulirsch & Li, 2022). Figure 2 shows a schematic diagram of PHAST, related applications, and how they work together. Users can enter a variety of data into the tool. PHAST will then generate site-specific doses and exposure concentrations, hazard quotients used to assess noncancer e ects, and cancer risk based on built-in default or user-defined site-specific scenarios for drinking water, surface water, soil, sediment, air, and food (Figure 3). PHAST also maintains a chemical database that contains health guideline information, media-specific screening values, and physical and chemical properties that are used in the Ed i tor ’s Not e : As part of our continued e ort to highlight innovative approaches to improve the health and environment of communities, the Journal is pleased to publish regular columns from the Agency for Toxic Substances and Disease Registry (ATSDR) at the Centers for Disease Control and Prevention (CDC). ATSDR serves the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and diseases related to toxic substances. The purpose of this column is to inform readers of ATSDR’s activities and initiatives to better understand the relationship between exposure to hazardous substances in the environment, its impact on human health, and how to protect public health. The findings and conclusions in this column are those of the author(s) and do not necessarily represent the oƒcial position of CDC, ATSDR, and the National Center for Environmental Health. Dr. Tonia Burk and Dr. Greg Ulirsch (retired) are environmental health scientists in the Associate Director for Science Oƒce within the Oƒce of Community Health and Hazard Assessment (OCHHA) at ATSDR. Dr. David Mellard is the associate director for science within the Oƒce of Capacity Development and Prevention Services at ATSDR. Dr. Zheng Li is the associate director for science within OCHHA at ATSDR. Public Health Assessment Site Tool and Affiliated Applications: A Key Resource for Evaluating the Health Impact of Community Exposure to Hazardous Chemicals Tonia Burk, PhD David Mellard, PhD Gregory V. Ulirsch, PhD Zheng Li, PhD