Environmental Engineering Reference
In-Depth Information
Regulations and Recommendations for
Reducing Exposure to Mercury
The FDA has set an informal “action level” of 1 ppm for
mercury in fi sh. Agencies in the European Union, United
Kingdom, and Canada have used 0.5 ppm as a criterion,
with exceptions for certain predatory species, which are
allowed to contain up to 1 ppm. The potential diffi culties
of enforcing government regulations have led some sea-
food restaurants and retailers in the United States to start
their own screening and labeling programs (Burros, 2008).
A number of laws have been enacted in the United States
to prevent or reduce the release of mercury into the envi-
ronment. The Clean Water Act requires states to adopt
water-quality standards for their rivers, streams, lakes,
and wetlands. These standards identify maximum levels
for mercury and other pollutants to protect the health of
humans, as well as fi sh and wildlife. The Clean Air Act is
another key environmental law that regulates 188 hazard-
ous air pollutants, including mercury. In the United States,
the EPA is responsible for developing and enforcing many
of the regulations that implement federal environmental
laws (US EPA, 2008a). EPA regulations include rules for
reducing mercury emissions from coal-fi red power plants,
chlor-alkali and other industrial plants, boilers, solid-waste
combustion, and other sources.
Individual states share responsibility for developing and
enforcing related regulations. In 1999, states in the Northeast
and other parts of the country began to enact legislation to
reduce mercury in products and waste. In 2001, the Northeast
Waste Management Offi cials' Association (NEWMOA)
launched the Interstate Mercury Education and Reduction
Clearinghouse (IMERC) to provide technical and program-
matic assistance to states that have enacted mercury educa-
tion and reduction legislation (NEWMOA, 2007). The IMERC
also provides information on mercury-added products and
member states' mercury education and reduction programs to
industry and the public. State legislation has included bans
on the sale of mercury-containing thermometers, toys, and
other products and regulations for their disposal; prohibition
of elemental mercury sale for anything other than research,
medical, or manufacturing purposes; as well as bans on the
use of elemental mercury in classrooms.
More controversial legislation involves limiting the use
of mercury amalgams for dental restorations. In several US
states, dentists must now obtain informed consent from
patients receiving mercury amalgam restorations (Edlich
et al., 2008), and the FDA is considering a recommenda-
tion to limit use during pregnancy. Legislators in Denmark,
Sweden, and Norway have banned the use of mercury amal-
gams (Edlich et al., 2008), while Germany limits their use
to adults and nonpregnant women (Schulz et al., 2007b).
Some claim that the absence of evidence for harmful effects
of amalgams combined with their affordability and durabil-
ity argues against limiting their use (Beazoglou et al., 2007).
Fish is probably the most important source of exposure
to mercury in the general population, because the methyl-
mercury in fi sh tissue can be severely neurotoxic. However,
regulating exposure directly from fi sh consumption is
diffi cult. It is prohibitively expensive and time-consuming
to screen all fi sh and seafood products that come into the
market. Even fi sh species known to contain the highest con-
centrations of mercury will have varying levels, depending
on the source and size of the specimen (Sunderland, 2007).
Fish Consumption Advisories
As an alternative to regulation, advisories can help guide
individuals in reducing exposure to methylmercury from
fi sh consumption on their own. In January 2001, the FDA
disseminated a consumer advisory on mercury in fi sh
directed at groups considered to be at the highest risk:
women who might become pregnant, women who are
pregnant, nursing mothers, and young children. The advi-
sory recommended avoiding the four most contaminated
fi sh species (shark, swordfi sh, king mackerel, and tilefi sh)
and limiting overall consumption of fi sh and shellfi sh to
12 oz/week or less. In 2004, the FDA reissued the advisory
jointly with the EPA, emphasizing the nutritional benefi ts
of fi sh, adding a suggested restriction in consumption of
canned white (albacore) tuna, and including examples of
species that are low in methylmercury (FDA/EPA, 2004).
Individual states have primary responsibility for collect-
ing data and issuing advisories on mercury in recreationally
caught fi sh from local bodies of water. Some states and locali-
ties provide advice for commercial fi sh consumption as well
(US EPA, 2008c). Their recommendations may include infor-
mation on a greater number of species that are of potential
relevance to the local population (New York City Department
of Health and Mental Hygiene, 2007; Washington State
Department of Health, 2008). Advisories differ from state to
state based on the choice of guidelines for determining allow-
able methylmercury intake, fi sh species listed, and defi nitions
of average body weight and portion size.
In addition to advice issued by federal and state govern-
ments, not-for-profi t groups also provide information on mer-
cury in fi sh directly to consumers. For example, the Natural
Resources Defense Council and the Turtle Island Restoration
Network provide online mercury calculators (www.nrdc.org
and www.gotmercury.org), which allow consumers to cal-
culate whether their mercury intake exceeds the EPA's RfD,
based on their body weight and combinations of fi sh spe-
cies consumed. Other groups, such as Physicians for Social
Responsibility and the Environmental Working Group, pro-
vide web-based lists of fi sh species with higher and lower mer-
cury concentrations, along with consumption guidelines.
Several studies have attempted to assess the level of infl u-
ence that the FDA/EPA advisories have had on fi sh con-
sumption in the United States. Knowledge of methylmer-
cury in fi sh was measured in the nationally representative
Food Safety Surveys, 2001 and 2006 (Lando and Zhang,
2011). Awareness of mercury as a problem in fi sh rose from
