Mercury Myths and Facts

MYTH: Mercury emissions from coal-fired power plants in Illinois represent a significant public health hazard because mercury gets into the fish we eat.

FACT: Most of the man-made mercury that gets into fish consumed by Americans occurs naturally on the earth and in the air. U.S. power plants account for only 1 percent of total mercury emissions worldwide.  Illinois burns only 5.5 percent of the coal burned in the U.S. to produce electricity.

Seventy percent of the mercury deposited in the U.S. comes from natural sources and non-U.S. emissions primarily from Asia, and China in particular. Natural sources include oceans, volcanoes and wildfires.

Because mercury is a naturally occurring element released by natural processes, the levels of methylmercury in fish can never reach zero.  Mercury is a global issue that requires a global response—and the United States is the first country to regulate mercury emissions from power plants.

MYTH: Mercury emissions in the U.S. are on the rise.

FACT: Mercury emissions in the United States have significantly decreased since 1990.  From 1995 to 1999, mercury emissions from power plants decreased by 38 percent*, without mercury regulations and during a period of increasing energy demand. Through the USEPA’s Clean Air Mercury Rule, mercury emissions from power plants will continue to decline.

MYTH: Local mercury emissions from coal-fired power plants create local mercury “hot spots” in Lake Michigan and other Illinois waterways.

FACT: The type of coal used in most Illinois power plants does not produce emissions that result in significant local deposition of mercury. Instead, emissions produced by this kind of coal rise into the upper atmosphere, and do not fall back to earth locally.

The independent, non-profit Electric Power Research Institute (EPRI) applied state-of-the-art modeling to evaluate potential mercury “hot spots” and found that mercury emissions from power plants contribute little to the areas of highest deposition in the United States, either currently or in future regulated scenarios.

MYTH: Mercury in the U.S. environment at today’s levels is a threat to children’s health.

FACT: The U.S. Centers for Disease Control and Prevention doesn’t think so. In a 2005 study of methylmercury levels in the U.S. population, none of the people studied, including children, had levels that were high enough to place them at risk.

While USEPA’s advisory thresholds are set at one-tenth of the actual risk-concern level, none of the children even reached this threshold, and only one woman barely exceeded the threshold.

Depending on the types and quantities of fish they eat, women of childbearing age are unlikely to have anything to worry about if they follow federal guidelines.

The U.S. Food and Drug Administration (FDA) has worked with the USEPA to develop advice for consumers regarding methylmercury and fish consumption. That advice warns pregnant women not to eat shark, swordfish, king mackerel or tilefish because they may contain high levels of methylmercury. However, for their health and the health of their babies, pregnant women are advised to eat up to 12 ounces (two average meals) a week of a variety of fish and shellfish that are low in mercury, such as shrimp, canned light tuna, salmon, Pollock and catfish.

Fish are a good source of nutrients called omega-3 fatty acids. A study by Dr. Joseph Hibbeln of the National Institutes of Health, reported in The Economist (January 2006) finds that the benefits to women and children of eating fish high in omega-3s greatly outweigh the risks from the methylmercury in them.

MYTH: Fish advisories warning against eating fish from Illinois waterways illustrate the health risks associated with mercury from Illinois power plants.

FACT: Statewide fish consumption advisories are not an accurate indication that there are high levels of methylmercury in all locally caught fish.  These consumption advisories are often based on only a few samples and may be indicative of only isolated findings of contamination.
The Illinois Fish Contaminant Monitoring Program screens fish samples from about 40 bodies of water per year for contamination from pesticides and industrial chemicals.  

The state itself contains more than 87,000 miles of streams and 91,400 inland lakes and ponds, the majority of which have never been sampled for fish contaminants, although they are all covered by the statewide mercury advisory. 

Sampling, when done, is also not performed on a random basis, which may lead to misinterpretation regarding the exact extent and/or locations of potential concern.   Samples obtained are also assessed using varying standards from year to year, which makes the data unusable to track any long-term trends within the state.   The sampling methods and chemical analyses used are also not necessarily consistent with other states’ protocols, or with USEPA guidelines, making any comparisons across state borders of no value. 

Statewide advisories can be issued for a variety of reasons, many of which may inadvertently or deliberately overstate the actual level of concern for most water bodies. 

In most cases, they have been issued because of analytical results from sampling done in one part of the state, without specific information on whether other regions are similarly affected    This practice highlights the precautionary nature of such advisories and how they should be viewed by the public.   

The advisories themselves also contain statements promoting the consumption for fish, if done according to state guidance:  The acknowledgement that “fish and shellfish are an important part of a healthy diet” and “nearly all fish and shellfish contain traces of mercury” is consistent with the 2004 USEPA and FDA national advice concerning mercury in fish.

The statewide fish consumption advisories are based primarily on protecting sensitive populations, and include a wide margin of safety for the general public.  

Current advisories are intended to assist anglers and consumers of fish in selecting fish low in chemical contaminants as part of a healthy, balanced diet, and should NOT be regarded by the general public as an overall deterrent for eating fish.

The number of fish consumption advisories across the nation has increased over the years, not necessarily because of increased levels or frequency of contamination, but because of the increased monitoring effort in some states.  According to the USEPA, statewide advisories are issued primarily as a precautionary measure and are not necessarily based on evidence of increased contamination or demonstrated health risks.  

MYTH:  Mercury emissions from Illinois power plants can be reduced by 90 percent between now and 2009.

FACT: The technology needed to achieve significant reductions in mercury emissions is still being developed and tested. That’s why the USEPA’s mercury rule provides energy generators more time to plan, implement controls and achieve deep reductions in mercury emissions. In fact, Illinois power generators are currently participating in federal government field tests of mercury control technologies.

In early February, the U.S. Department of Energy announced that it is funding 12 more field tests that will last from 20 to 36 months, demonstrating further that the federal government recognizes that we still have a lot to learn and develop between now and 2009.  It is unrealistic to assume that we can reduce mercury emissions by 90 percent in less than three years, as proposed by Governor Blagojevich.

MYTH: Illinois would only be doing what several other states are doing in cutting mercury emissions more steeply than the federal rule.

FACT: Most states recognize that air quality is by its nature a national issue and should be regulated by the federal government. Six states—Iowa, North Dakota, South Dakota, Missouri, Kentucky and West Virginia—are already planning to implement the federal rule as it is written; Indiana, Ohio and Texas will likely follow.

To the extent that a few other states have enacted or are considering their own mercury rules, their proposals are generally not as severe as the one under consideration in Illinois.

Those states that have adopted rules stricter than the federal mercury rules have mainly been eastern states that rely very little on coal-fired energy generation.  Closer to home, Michigan and Minnesota are considering stricter standards but may also allow power generators to recover their costs so they are not disadvantaged in the competitive marketplace.

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*Source: Pombo, Richard W. and Gibbons, Jim. "Mercury in Perspective"