Review of the Minnesota Department of Health contaminants of emerging concern program process for selecting chemicals

The legislative mandate for the Drinking Water Contaminants of Emerging Concern (CEC) program is quite short. It was created in response to Minnesota laws in 20091 and 20112 that appropriated Clean Water Fund money “for addressing public health concerns related to contaminants found in Minnesota drinking water for which no health-based drinking water standard exists.” MDH was required to “characterize and issue health-based guidance” for 10 chemicals in the first biennium. The CEC program is part of the Health Risk Assessment Unit of the MDH. The program is staffed by three toxicologists, one exposure scientist, one risk assessor, and one communicator. The toxicity and exposure screening processes were originally designed in 2010-2011 in consultation with a Contaminant Selection Criteria and Prioritization Development Task Group comprised of specialists assembled by CEC staff from state agencies, universities, private business, cities, and environmental advocacy groups. 


The University of Minnesota was designated by the Legislature to conduct the review. Personnel from the Water Resources Center and the Humphrey School of Public Affairs collaborated on the project. The review consisted of fact gathering regarding the MDH CEC program, a literature review of scientific articles related to chemicals of emerging concern and processes for screening these chemicals, analysis of similar programs in federal agencies and other jurisdictions, and evaluation of the CEC screening process by a panel of scientists and by a panel of stakeholders. Although the University of Minnesota team discussed its recommendations with the scientists and stakeholders and with MDH, the recommendations are the product of the University of Minnesota team. The overall conclusion was that the MDH CEC program is sound but that MDH needed to improve and clarify several steps in the process and expand its efforts to engage stakeholders and the public.

Following the review, the University of Minnesota project team recommends:

  1. MDH should preserve and publicize the valuable services of the CEC program.
  2. MDH should maintain the Internet-based tool for nominating chemicals for consideration in the CEC program. At the same time, it should engage with membership organizations, for example, the Sierra Club, Clean Water Action or the AARP, that represent individual citizens in developing a communication effort that will increase awareness of the CEC program and awareness of the nomination process.
  3. MDH should build on known sources of expertise to develop new methods for systematically nominating chemicals for screening, in addition to relying on voluntary nomination and communicating closely with key agency staff.
  4. MDH should publish on their CEC website the process and criteria for assigning categories, summarizing data groups, and combining scores into overall rankings.
  5. For clarity in the screening worksheet, MDH should evaluate cumulative effects and reaction products separately.
  6. So it is transparent to stakeholders, MDH should describe its method (if it has one) for identifying reaction products and mixtures with cumulative effects as CECs that may require full evaluations.
  7. To keep up with the complexity and dynamic nature of chemical exposure science, MDH should incorporate regular consultations with exposure specialists beyond the CEC program staff.
  8. MDH should calculate Hazard Quotients (HQs) for currently screened chemicals to assess how the HQ impacts the ranking of chemicals, how much time the calculation requires, the feasibility of the calculations, and whether the use of the HQ is clear to stakeholders or creates more misunderstanding of the uncertainty involved. If the trial shows the HQ is helpful for ranking or communication, it should be incorporated into the screening process.
  9. MDH should consider using a “weight of evidence” approach to help streamline the interpretation of toxicological and exposure data and make the process more transparent.
  10. MDH should clarify how it is defining “usefulness” of health-based guidance.
  11. MDH should increase the engagement of stakeholders during the screening and selection process to help make the process more transparent and inject more information about the nature of needs for health guidance. This engagement should go beyond informal contact with state agencies to reach other stakeholders. To maintain agency accountability, the final decision on chemical selections should remain with CEC program staff.
  12. To increase public and stakeholder awareness of the CEC program, MDH should consult with a variety of stakeholders to learn what information they most need, reorganize the CEC website to reflect user needs and add additional communication methods to its current communications activities.

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