title: Illustrative case using the RISK21 roadmap and matrix: prioritization for evaluation of chemicals found in drinking water.
abstract: The HESI-led RISK21 effort has developed a framework supporting the use of twenty-first century technology in obtaining and using information for chemical risk assessment. This framework represents a problem formulation-based, exposure-driven, tiered data acquisition approach that leads to an informed decision on human health safety to be made when sufficient evidence is available. It provides a transparent and consistent approach to evaluate information in order to maximize the ability of assessments to inform decisions and to optimize the use of resources. To demonstrate the application of the framework's roadmap and matrix, this case study evaluates a large number of chemicals that could be present in drinking water. The focus is to prioritize which of these should be considered for human health risk as individual contaminants. The example evaluates 20 potential drinking water contaminants, using the tiered RISK21 approach in combination with graphical representation of information at each step, using the RISK21 matrix. Utilizing the framework, 11 of the 20 chemicals were assigned low priority based on available exposure data alone, which demonstrated that exposure was extremely low. The remaining nine chemicals were further evaluated, using refined estimates of toxicity based on readily available data, with three deemed high priority for further evaluation. In the present case study, it was determined that the greatest value of additional information would be from improved exposure models and not from additional hazard characterization.
authors.affiliation: a Syngenta Crop Protection LLC , Greensboro , NC , USA.
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Wolf
authors.affiliation: b ExxonMobil Biomedical Sciences, Inc. , Annandale , NJ , USA.
authors.forename: Ammie
authors.initials: A
authors.lastname: Bachman
authors.affiliation: c Health Canada , Ottawa , Ontario , Canada.
authors.forename: Gordon
authors.initials: G
authors.lastname: Barrett
authors.affiliation: d DuPont Haskell Global Centers for Health & Environmental Sciences , Newark , DE , USA.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Bellin
authors.affiliation: e Pharmcology & Toxicology, Michigan State University , East Lansing , MI , USA.
authors.forename: Jay I
authors.initials: JI
authors.lastname: Goodman
authors.affiliation: f Department of Biomedical & Clinical Sciences, University of Milan , Milan , Italy.
authors.forename: Elke
authors.initials: E
authors.lastname: Jensen
authors.affiliation: f Department of Biomedical & Clinical Sciences, University of Milan , Milan , Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Moretto
authors.affiliation: g Dow Corning Corporation , Midland , MI , USA.
authors.forename: Tami
authors.initials: T
authors.lastname: McMullin
authors.affiliation: a Syngenta Crop Protection LLC , Greensboro , NC , USA.
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Pastoor
authors.affiliation: h United States Environmental Protection Agency , Washington, DC , USA.
authors.forename: Rita
authors.initials: R
authors.lastname: Schoeny
authors.affiliation: d DuPont Haskell Global Centers for Health & Environmental Sciences , Newark , DE , USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Slezak
authors.affiliation: i Department of Orthopaedic Surgery , UCLA and Orthopaedic Hospital , Los Angeles , CA , USA.|j Orthopaedic Hospital Research Center, David Geffen School of Medicine at UCLA , Los Angeles , CA , USA.
authors.forename: Korinna
authors.initials: K
authors.lastname: Wend
authors.affiliation: k ILSI Health and Environmental Sciences Institute , Washington, DC , USA.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Embry
mesh_terms: D000818:Animals; D003657:Decision Making; D060766:Drinking Water / Q000032:analysis*; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D015386:Hazardous Substances / Q000633:toxicity*; D006801:Humans; D023421:Models, Animal; D008962:Models, Theoretical; D018570:Risk Assessment; D018675:Toxicity Tests; D014481:United States; D014484:United States Environmental Protection Agency
chemical_list: D060766:Drinking Water; D015386:Hazardous Substances
keywords: Drinking water; RISK21; integrated evaluation strategy; prioritization; risk assessment; tiered approach