According to environmental groups, U.S. consumers should start monitoring their swordfish intake, just as they are watching their intake of salmon, because of rising levels of mercury found in swordfish at many supermarket chains.
Tests done at the University of North Carolina laboratories found that swordfish being sold at Safeway, Albertsons and Whole Foods have, on average, 10% more mercury than federal regulations permit.
Out of 24 samples tested, the average was 1.1 parts per million. Federal limits are set at 1 part per million. 9% of the samples had twice the limit.
In response to these findings, environmental groups are seeking further government tests.
They are also asking that warning labels be put on the products in all stores, instead of just some stores.
Methylmercury, which is the form of mercury found in some fish, is dangerous to humans. If a human is exposed to excessive amounts of mercury, he or she might suffer: damage to the nervous system; kidney damage (changes in kidney function); damage to developing fetuses; tremors; loss of sensation; irritability; skin rashes; eye irritation; an memory problems.
Exposure to small amounts of mercury in its various forms and compounds is normal, and happens regularly. If you stay within the safety limit of 1 part per million (food and drink), you have nothing to worry about.
Mercury poisoning, however, is a more serious situation. It can occur through breathing mercury vapor or handling droplets from a spill. Extreme caution should be used in cleaning up such spills so as to avoid dispersing toxic mercury vapor.
Mercury is a heavy metal which is poisonous to humans and animals. Two studies in the November 2002 issue of the New England Journal of Medicine presented contradictory findings about possible heart-related dangers from eating mercury-laden fish.
Past research, however, has shown that mercury found in fish can have harmful effects on the developing brain of a child or fetus. Thus, pregnant women are strongly cautioned to avoid eating the type of large, deep-sea predatory fish which are most prone to contain high concentrations of mercury. These include swordfish, albacore tuna, shark, and bluefish.
Other recent studies dealt with the long term effects of mercury exposure on the hearts of middle-aged and elderly men. While one study found that men who had suffered a heart attack had higher levels of mercury, the other found no correlation between mercury level in the body and the risk of developing heart disease.
In April of 2002, researchers at the Glasgow Royal Infirmary in Scotland conducted a study of 180 dentists and concluded that dentists are more likely to suffer memory and kidney problems as a result of long term exposure to the mercury used in tooth fillings.
The test group had up to four times the normal level of mercury in their urine and nail samples. While fillings can emit vapors that are harmful to both dentists and their patients, the dentist is more likely to experience health-related complications such as Alzheimer’s disease since they are subjected to ongoing exposure to the mercury.
Dental associations, however, claim that the mercury in fillings is safe when it is mixed with other metals.
If you believe that you have been exposed to significant amounts of mercury, you should ask your doctor to perform either a heavy metal blood test or hair test to determine the level of mercury in your body.
Some symptoms of an elevated mercury level are hair loss, tiredness, and short-term memory loss. In most cases, the effects of an elevated mercury level are reversible within a few months after the source of the mercury is eliminated.