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Guest Post from Integral Consulting: Integral Continues the Conversation Related to Doug’s Posts on Fish Consumption Rates

Posted in Clean Water Act, Emerging Policy, Environmental Risk, Fish Consumption, Geeky Science Stuff, Guest Posts, Water Quality

Note: This is the second guest post by Integral on this subject, it is also worth reviewing their prior post from February on this topic.

In addition to the updated national recommended water quality criteria discussed by Doug on May 20, EPA has recently released another document with implications for selection of an appropriate fish consumption rate (FCR) in developing water quality standards (WQS) for Washington State: Estimated Fish Consumption Rates for the U.S. Population and Selected Subpopulations (FCR Report).  This document is an evaluation of dietary data collected by the National Health and Nutrition Examination Survey between 2003 and 2010, and it provides the FCR selected by EPA in developing its 2014 proposed national ambient water quality criteria under Section 304(a) of the Clean Water Act.

Unlike EPA’s 2002 approach, the new analysis makes adjustments intended to address some of the biases associated with the use of short-term dietary data to predict long-term FCRs, thereby producing more accurate FCR estimates for the general population and population subgroups.  The FCR Report categorizes the consumption data in multiple ways, including the following:

  • Fish characteristics (three trophic levels; finfish vs. shellfish; and life histories involving marine, estuarine, freshwater, and combinations of habitats)
  • Consumer demographics (age, race, gender, and income)
  • Geographical areas (regions of the U.S., and coastal vs. non-coastal areas).

Although Native American tribal members and Asian Pacific Islanders are included in the results for “other races,” they are not distinguished as specific subpopulations in the FCR Report.

A review of the FCR Report produces some interesting observations about FCRs in the Pacific Northwest.  For example, the 99th percentile FCRs for total fish consumption (freshwater, estuarine, and marine finfish and shellfish) by all demographic groups are lower than 175 g/day, the rate assumed by the Oregon Department of Environmental Quality in its recent update to state WQS.  The Washington Department of Ecology (Ecology) has considered using this value for its revisions to its state WQS.

EPA has developed its ambient water quality criteria by identifying FCRs for different trophic level fish and shellfish and adjusting for their sources (marine, estuarine, freshwater).  These FCRs are then combined with chemical-, trophic level-, and source-specific bioaccumulation factors.  Important strengths of the FCR Report are inclusion of a correction for short-term recall bias; differentiation among trophic levels, age groups, and regions of the country; and apportionment of species to address the sources of the fish.  It may be possible for Washington State to obtain the state- and tribe-specific fish consumption rates from EPA to consider in selection of its FCR for rule-making.  Alternatively, a similar approach of separating FCRs by trophic level and source could be applied to data from local surveys to yield results that are more specific to Pacific Northwest populations.  We believe that Ecology’s proposed rule would be substantially strengthened by using this approach recommended by EPA.

Ecology is still indicating that it intends to have a final rule published by the end of the year but, as Doug noted in his June 13 post, the proposed rule won’t be available until later this summer.