Catching the Limit

Mercury Contamination of America's Food

Wednesday, December 17, 1997

Catching the Limit

Mercury Contamination of America's Food

Executive Summary

A long-overdue report to Congress confirms that mercury pollution from power generation and waste incineration is a serious environmental and public health problem. Not only is mercury extremely toxic to the developing human brain and nervous system, but it has become ubiquitous in the environment and commonly contaminates many foods, particularly fish, at levels of public health concern. According to the EPA, more than 1.6 million pregnant women, children, and women of child bearing age are exposed to unsafe levels of mercury from fish alone (EPA 1996).

Mercury gets into the environment primarily from combustion of wastes, including medical and municipal wastes and sludge, and the combustion of coal for power generation. In spite of the nation’s clean air and clean water laws, these major sources of mercury remain uncontrolled or poorly regulated. Mercury now contaminates fish so severely that it has triggered more than 1,600 government warnings against eating fish, so-called “fish consumption advisories”, in 37 states. Indeed, fish consumption advisories for mercury are on the rise, nearly doubling from 1993 to 1996 (EPA 1997). Nine of those states: Connecticut, Florida, Indiana, Massachusetts, Maine, Michigan, New Hampshire, New Jersey and Vermont have some form of statewide restrictions or prohibitions on fish consumption due to mercury contamination (EPA 1997).

Mercury in the food supply

Locally caught fish are not the only sources of mercury. Many fish items purchased at the local grocery store such as canned tuna, haddock, fish sticks and shrimp also contain mercury. Other foods that are sources of mercury include: spinach, oatmeal, and eggs. Notably, the EPA’s estimate that 1.6 million women and children are at risk does not include consumption of foods other than fish.

Reducing mercury emissions

The EPA report identifies a serious public health problem from mercury in the environment and the food supply. Recent EPA rules to reduce emissions from medical waste incinerators, however, will do virtually nothing to reduce current levels of mercury pollution. In fact, these regulations actually encourage continued burning of mercury containing waste because they do not require separation of mercury containing devices from the waste stream.

Medical sources of mercury are the simplest to eliminate, via costeffective source separation and substitution of non-mercury-containing products at medical facilities. Mercury-containing devices in the medical waste stream include batteries, thermometers, blood pressure cuffs, fluorescent lamps and feeding tubes. When incinerated, mercury is released into the air, or contained in the resulting ash destined for disposal on land. Mercury from other major sources also can be reduced dramatically with available pollution control technologies.


The EPA report should not cause most people to reduce their consumption of commercially caught fish although pregnant women should take the warnings quite seriously and limit consumption of all fish. The EPA report should serve as a call to arms for industry and government to slash mercury emissions and allow citizens to safely consume this important part of the diet.

  • EPA and FDA should require states to base fish consumption advisories on the most restrictive threshold available to ensure that populations who eat more than average amounts of fish are protected.
  • State agencies should require stricter emissions limits, and waste segregation programs for mercury as part of their implementation plans for the medical waste incinerator rule.
  • Medical facilities should begin a “mercury-free” campaign to phase out mercury containing products and segregate mercury waste as long as it remains in use.

The Health Care Without Harm Coalition is prepared to assist hospitals and states by providing expert advice from medical and environmental professionals who have a track record working with hospitals and other medical providers to reduce mercury emissions.


Download your state in Adobe Acrobat PDF Format



Table 1. Mercury contaminates commercially caught fish and many other foods.

Food Percent Contaminated Highest Mercury Contamination Level (ug/g) (ppm) Average Mercury Contamination Level (ug/g) (ppm)
Tuna, canned in oil 100 0.322 0.171
Haddock, pan-cooked 94 0.156 0.065
Tuna Noodle Casserole 88 0.063 0.02
Shrimp, boiled 94 0.053 0.024
Fish Sticks, Frozen, 75 0.03 0.009
Liver, Beef, Fried 31 0.03 0.003
Fish Sandwich, Fst Fd 44 0.021 0.004
Spinach, Fresh/Frozen 31 0.018 0.002
Oatmeal, Quick 13 0.012 0.001
Eggs, fried 6 0.01 0.001
Eggs, boiled 6 0.01 0.001
Mushrooms, raw 38 0.009 0.002
Avocado, raw 38 0.009 0.001
Eggs, scrambled 13 0.009 0.001
Crisped Rice Cereal 31 0.008 0.001

Source: Environmental Working Group. Compiled from FDA Total Diet Study, 1991-1996.

Table 2. All waters of a given type are unsafe for fish consumption in many states due to mercury contamination.

State Extent of advisory Types of Fish Under Advisory
Connecticut All freshwater bodies not under other advisory All fish
Florida All marine waters Shark
Indiana All Indiana rivers and streams Carp 15-25 inches
Massachusetts All state freshwater bodies
All marine waters
All fish
Maine All inland lakes and ponds All fish
Michigan All inland lakes Various sport fish
New Hampshire All inland inland lakes All Freshwater fish
New Jersey All freshwater bodies Chain pickerel, Largemouth bass
Vermont All waters statewide All species except bullhead and pumpkinseed

Source: Environmental Working Group. Compiled from EPA's Fish Consumption Advisory Database. Data from 1996.

Table 3. Many U.S. waters are not fishable due to mercury contamination.

State Number of Fish
due to Mercury
Minnesota* 693
Wisconsin 389
Indiana 116
Florida 94
Massachusetts 52
Michigan 41
North Dakota 35
New Jersey 30
New Mexico 26
South Carolina 24
Georgia 23
Montana 22
Arkansas 19
Ohio 19

*The high number of fish consumption advisories in Minnesota may be partially due to the thousands of different lakes in that state.

Source: Environmental Working Group. Compiled from EPA's Fish Consumption Advisory Database. Data from 1996.


News Release - EPA: 1.6 Million Kids, Moms At Risk of Mercury Poisoning

Warnings in 37 States Against Fresh-Caught Fish
Canned Tuna, Other Foods Also Contaminated

Fish from more than 1,660 U.S. waterways are so contaminated with mercury that they should not be eaten or eaten only in limited amounts, according to federal health warnings analyzed by the Environmental Working Group (EWG). Children and mothers-to-be are at highest risk, not only from fresh fish but from mercury contamination of canned tuna and other foods.

The EWG study lists all fish advisories from mercury contamination in 37 states, as well as mercury levels found in supermarket products such as tuna, fish sticks, even instant oatmeal. (See tables). The study will be released nationwide on Wednesday, Dec. 17 - two days before the EPA sends Congress an report estimating that more than 1.6 million women and children may face serious health risks from mercury-contaminated food.

"The EPA report says that eating just half a can of tuna a day could exceed safe levels for mercury exposure," said EWG analyst Jacqueline Savitz. "The solution is not to stop eating fish, but to minimize the sources of mercury contamination."

Among EWG's findings:

* In nine states -- Connecticut, Florida, Indiana, Massachusetts, Maine, Michigan, New Hampshire, New Jersey and Vermont -- mercury contamination is so widespread that statewide advisories against fish consumption are in effect.

* Of other states, mercury contamination is most widespread in the Midwest: Minnesota leads the nation with 693 fish consumption advisories, following by Wisconsin with 389 and Indiana with 116.

* FDA tests found that 100 percent of samples of oil-packed canned tuna were contaminated with mercury. Mercury was found in more than 90 percent of commercial haddock and shrimp, and in 75 percent of frozen fish sticks.

The EPA report defines the nation's mercury problem, but the agency has failed to enact adequate regulations to prevent mercury pollution that results from incineration of medical and municipal waste. A national coalition, Health Care Without Harm, is calling on medical facilities to rapidly phase out the unnecessary use of mercury.

Key Issues: