The Turf Battle
Fish consumption advisories have been around since the 70’s,
when the main concern was contamination of fish with PCB’s. Since then, every state health department
issues lake-specific advisories for recreationally caught fish, and a branch
was established in the EPA Office of Water in 1993 to coordinate advisories
among and with state health departments.
While PCB’s and other contaminants are occasionally the impetus for fish
consumption advice, the main culprit is usually methylmercury. Typically, these guidelines were designed to
keep consumers exposure below the Reference Dose. That doesn’t sound so bad, and it wouldn’t be
if the RfD was thought of as a rough guideline (e.g. like yellow traffic
warning signs). But, because the EPA
speaks of the RfD as a fact, it is trouble.
The USFDA initially attempted to limit exposure to
methylmercury in fish by setting action levels and attempting to ban
swordfish. However, the legal authority
that the USFDA has over contaminants in food proved to be too limited. There was also a serious practical
limitation; given the wide variation of methylmercury levels in different fish,
even in the same species, enforcing an action level would require testing
individual fish. So, beginning in 1995,
the USFDA also began to use consumption advisories for methylmercury. The first one advised pregnant women to
consume shark and swordfish no more than once a month, and a later advisory
issued in 2001.
Shortly thereafter, an FDA advisory committee suggested that
in order to avoid conflicting advice from the federal government, FDA and the
EPA should issue advice jointly. With
some difficulty, this happened. Both agencies agreed on what advice should be
given, which in addition to restricting consumption of particular species of
fish, suggesting an overall limit of 12 ozs of fish per week. However, in no way was the rationale for the
advice agreed upon. For the EPA, the 12
oz limit was necessary to prevent the Reference Dose from being exceeded, while
for the FDA the 12 oz limit allowed consumers to avoid the risk of not eating
enough fish.
Part of the conflict arises from the regulatory role of the
offices involved. The Division of
Seafood in the FDA has a mandate to regulate seafood sold in interstate
commerce, while the fish advisory group at the EPA is primarily concerned with
recreational fish. So, while the FDA
Division of Seafood regulates a business, the EPA Office of Water doesn’t. But, that hasn’t stopped the Office of Water
from broadening its scope to include
commercial seafood. So, a big part
of the Fish War is a conflict over keeping control of the decision
process. By using the RfD as an
instrument of control, the EPA has sought to extend the RfD-based rationale for
recreational advisories. Even if the
advice is agreed upon, the USFDA has felt compelled to have a more defensible
rationale for audience that includes both consumers and a regulated industry.
Not having gotten the memo about the need for coordinated
federal fish consumption advice, the 2010 Dietary Guidelines for Americans
(DGA) was jointly issued by USDA and a non-FDA component of HHS. This advice was close to the joint EPA/FDA
advisory, but instead of a consumption limit, it gives a recommended
consumption range of 8-12 ozs/week. The
EPA and FDA once again got together to craft an advisory that would be
consistent with the DGA guidelines, and once again they agreed on the advice
without agreeing on the rationale. The
USFDA used a risk assessment that considered both risks and benefits of
consuming fish (USFDA, 2014), while the EPA still prefers to tout the RfD. The USEPA stood pat with the Reference
Dose. The 2015 Dietary Guidelines are
now out, and they have advised the EPA and FDA to drop the specific
recommendation for albacore. The turf
battle seems to have expanded to another front.
Dueling Paradigms
The paradigm battle is related to the turf battle. But it isn’t really about just methylmercury
or fish; it’s about how decisions get made.
As only one instance of the
conflict that arises when shell gamers confront nonplayers, it transcends
methylmercury and fish. As an object
lesson about the interaction between science and politics in general, it transcends
chemical contaminants in food. It’s
about the pursuit of control vs. the pursuit of truth. It’s about Neo vs. the Machines and
it’s a
Treatise on Human Nature.
Using the RfD as the basis for personal policy shares some
of the same limitations as when it is used for public policy – it provides the personal
policy maker (aka a consumer) very little information. Using the RfD as the basis for a food
consumption advisory may tell a person what to do, but it doesn’t say why (e.g.
see Goyer
letter). A quantitative risk
assessment (QRA) does. For example,
using several different models (Carrington and Bolger, 2000; Axelrad et al, 2007), the risk at the RfD is a
reduction of about 0.2 IQ points, give or take a factor of 2. Micromanaging fish consumption around the RfD
isn’t going the change the fact that the risk is still about 0.2 IQ points
regardless of whether or not the exposure is a little more or a little less
than the RfD. Furthermore, since some of
the methylmercury comes from unknown non-fish sources (USEPA, 2013), not all of
the risk is avoidable in any case.
The EPA Office of Water does not have any use for quantitative
risk assessment. They do not want
estimates that are approximately correct no matter how approximately correct
they are. So, it really isn’t a
disagreement over the science. Furthermore, the
paradigm conflict doesn’t follow agency borders. Using the dose-response characterization
developed by the EPA Office of Air (Axelrad et al, 2007) instead of our own
(Carrington and Bolger, 2000) didn’t placate them at all. Proponents of shell-game infused safety
assessment paradigm within the Department of Health and Human Services haven’t
been very appreciative of QRA either. Unless
it somehow magically makes the RfD actually become a threshold with no
variability or uncertainty, any dose-response characterization is going to make
the RfD for methylmercury irrelevant. If
you think the RfD is a source of great moral precautionary authority, that
would be bad. Nonetheless, as a result
of the efforts of a steadfast turf warrior (not me), the FDA QRA is presented on
the FDA website (USFDA, 2014). Unlike
the joint advisory, the risk-benefit assessment belongs only to the FDA.
To Be Continued
As an ex-FDA employee, the turf battle is over for me. I joined as a soldier in the war, but it
never really did interest me. However,
the paradigm battle is far from over. In
fact, I hope to be able to fight it more effectively without the entanglements
of bureaucratic interests. The paradigm
battle has a political cause that can only have a political solution. For dueling with the shell game, the FDA
presentation of the QRA is less than ideal.
When the consumer is the risk manager, the QRA needs a more personal
presentation.
References
Axelrad D.A., Bellinger, D.C., Ryan L.M., and Woodruff T.J.
(2007), Dose-Response Relationship of Prenatal Mercury Exposure and IQ: An Integrative Analysis of Epidemiological
Data. Environmental Health Perspectives
Carrington, CD and Bolger, PM (2000). A Pooled Analysis of the Iraqi and Seychelles
Methylmercury Studies. Human Ecological Risk Assessment 6:323-340.
U.S. Environmental Protection Agency (2013). Trends in Blood Mercury Concentrations and
Fish Consumption Among U.S. Women of Childbearing Age NHANES, 1999-2010. Final
Report July 2013 EPA-823-R-13-002.
USEPA and USFDA (2004).
What
You Need to Know About Mercury in Fish and Shellfish.
USFDA and USEPA (2014).
Fish: What Pregnant Women and Parents Should Know. Draft
Updated Advice by FDA and EPA / June 2014.
U.S. Food and Drug Administration (2014). Quantitative
Assessment of the Net Effects on Fetal Neurodevelopment from Eating Commercial
Fish (As Measured by IQ and also by Early Age Verbal Development in Children).
Official Post Soundtrack
Cliff, Jimmy (1989). The Grass is Greener. In: Images, Track 12.Post Note
Thesis Post #31. First post as an ex-Federal employee.
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