title: Using a relative health indicator (RHI) metric to estimate health risk reductions in drinking water.
abstract: When a new drinking water regulation is being developed, the USEPA conducts a health risk reduction and cost analysis to, in part, estimate quantifiable and non-quantifiable cost and benefits of the various regulatory alternatives. Numerous methodologies are available for cumulative risk assessment ranging from primarily qualitative to primarily quantitative. This research developed a summary metric of relative cumulative health impacts resulting from drinking water, the relative health indicator (RHI). An intermediate level of quantification and modeling was chosen, one which retains the concept of an aggregated metric of public health impact and hence allows for comparisons to be made across "cups of water," but avoids the need for development and use of complex models that are beyond the existing state of the science. Using the USEPA Six-Year Review data and available national occurrence surveys of drinking water contaminants, the metric is used to test risk reduction as it pertains to the implementation of the arsenic and uranium maximum contaminant levels and quantify "meaningful" risk reduction. Uranium represented the threshold risk reduction against which national non-compliance risk reduction was compared for arsenic, nitrate, and radium. Arsenic non-compliance is most significant and efforts focused on bringing those non-compliant utilities into compliance with the 10 μg/L maximum contaminant level would meet the threshold for meaningful risk reduction.
authors.affiliation: Columbia Water Center, Earth Institute, Columbia University, 500 W120 Street, Mudd 842, NY, New York, 10027, USA. katherine.alfredo@fulbrightmail.org.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Alfredo
authors.affiliation: Corona Environmental Consulting, LLC, 357 South McCaslin Blvd., Suite 200, Louisville, CO, 80027, USA.|DeRISK Center, University of Colorado Boulder, 1111 Engineering Drive, Boulder, CO, 80309-0428, USA.
authors.forename: Chad
authors.initials: C
authors.lastname: Seidel
authors.affiliation: Corona Environmental Consulting, LLC, 1600 Shadywood Lane, Flower Mound, Texas, 75028, USA.
authors.forename: Amlan
authors.initials: A
authors.lastname: Ghosh
authors.affiliation: Association of State Drinking Water Administrators (ASDWA), 1401 Wilson Blvd, Arlington, Virginia, USA.
authors.forename: J Alan
authors.initials: JA
authors.lastname: Roberson
mesh_terms: D001151:Arsenic / Q000032:analysis; D060766:Drinking Water / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D011634:Public Health; D011883:Radium / Q000032:analysis; D018570:Risk Assessment; D040242:Risk Reduction Behavior; D014481:United States; D014484:United States Environmental Protection Agency; D014501:Uranium / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014876:Water Pollution / Q000032:analysis; D014881:Water Supply / Q000592:standards*
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D014501:Uranium; D001151:Arsenic; D011883:Radium
keywords: Drinking water; Health risk; Regulation; Regulatory determination; USEPA