Tuesday, March 15, 2011

Chemical Month | Mercury

Canned tuna is America's favorite source of fish. It is also a source of mercury, which is not good

[Editor's note: March is "Chemical Month" on 13.7 Billion Years. From the neurotransmitters in our brains to the pesticides on our produce, from toxic substances found in most households to disease-preventing antioxidants, chemicals are both critical and dangerous to life on Earth. Each weekday this month, 13.7 Billion Years takes a look at a general chemical-based issue or a specific chemical from the vast laboratory of our daily lives.]

U.S. federal guidelines allow up to 12 ounces of canned light tuna and up to 6 ounces of white tuna per week for younger women and children, but the non-profit advocacy group Consumers Union says that doesn't go far enough.

"Canned tuna, especially white, tends to be high in mercury, and younger women and children should limit how much they eat. As a precaution, pregnant women should avoid tuna entirely," said Dr. Urvashi Rangan, director of technical policy at Consumers Union, which publishes Consumer Reports.

Mercury (Hg) is a heavy metal that has been shown to impair nervous system development in fetuses. Mercury poisoning can cause several diseases, such as Hunter-Russell syndrome, acrodynia and Minimata disease, as well as damage to the brain, lungs and kidney.

Fish consumption is the most common cause of mercury exposure in humans. A University of Hokkaido test of whale meat (which is illegal) purchased in the whaling town of Taiji found mercury levels more than 20 times the acceptable standard in Japan.

"Some studies have linked even low-level mercury exposure in pregnant women and young children to subtle impairments in hearing, hand-eye coordination, and learning ability," according to Food Safety News.

The FDA and EPA advise pregnant women to avoid swordfish, shark, king mackerel and tilefish as well.

Seafood is a source of healthy omega-3 fatty acids. However, this nutrient can be accessed without eating fish. Omega-3 is present in flaxseed, hempseed, canola oil, and walnuts, and can be converted into useful forms by the additional consumption of protein, pyroxidine (vitamin B6), biotin (B7), calcium, copper, magnesium and zinc.

  • Sign Pamela Anderson's pledge to explore vegetarianism for 30 days
  • Download a free vegetarian starter kit
  • Check out Meatout
  • Read the Yale College Vegetarian Society's "Top 10 Reasons to Become Vegetarian"
  • Follow 13.7 Billion Years on Twitter
  • Help Japan
  • Help children in Japan: Donate to the U.S. Fund for UNICEF's emergency appeal to help quake victims
  • Sign the Humane Society 2011 Boycott to Save Seals
  • Sign for stronger animal welfare laws in India
  • Tell Walmart and Supervalu to stop selling endangered fish
  • Sign to stop the burning, mutilating and neglecting of animals at University of Texas
  • Sign to stop abuse of New York City carriage horses
  • Sign to protect radio-collared bears from hunters in Minnesota
  • Sign to support H.R. 835 Puppy Uniform Protection and Safety (PUPS) Act
  • Help America's mustangs survive and SAY NO to $12 million hike in BLM budget which would fund more cruel roundups
  • Tell BLM solar energy needs to be in areas with few environmental conflicts
Also on 13.7 Billion Years: "Reports from 2050," a series of imagined reports from the year 2050, supported by current news, recent discoveries and scientific predictions.

image: michele_brl

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