Mercury releases from chlorine production

This week, Oceana, a nonprofit that works to protect the world's oceans, released a new report, Cleaning UP: Taking mercury-free chlorine production to the bank. Their report outlines how a handful of producers are still releasing large amounts of mercury when there are cost-effective alternatives. According to their report, "Globally, the chlorine industry had largely moved to mercury-free technology by the turn of the 21st century. In the United States, the industry reported that by 2004, 90 percent of its chlorine was produced using mercury-free technology and no new mercury-cell plant has been built since 1970. Oceana’s Campaign to Stop Seafood Contamination targets the plants responsible for the remaining 10 percent."

Why does this matter? Because mercury is a known toxic, and persistent chemical: once it is released into the global mercury pool, it doesn't go away. Mercury is then deposited in the oceans, where it is taken up at first in microorganisms. These are eaten by higher organisms, which are eaten by higher organisms, which in turn are eaten by even higher organisms. The mercury eventually finds its way into the fish we eat. The predator species in the oceans, such as tuna, shark, and swordfish, have some of the highest levels of mercury in their flesh.

In 2004, the Food and Drug Administration and the Environmental Protection Agency jointly issued an advisory on fish consumption to begin addressing mercury concerns. The mercury in fish can be dangerous to anyone, but babies in the womb and small children are particularly vulnerable, so the federal advisory recommends that women who may become pregnant, pregnant women, nursing mothers, and young children avoid some types of fish and eat fish and shellfish that are lower in mercury.

By following these 3 recommendations for selecting and eating fish or shellfish, women and young children will receive the benefits of eating fish and shellfish and be confident that they have reduced their exposure to the harmful effects of mercury.

1. Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury.

2. Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury.

   • Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.

   • Another commonly eaten fish, albacore ("white") tuna has more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week.

3. Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don't consume any other fish during that week.

The Environmental Defense Fund has a great site on fish consumption recommendations at their Oceans Alive website.

Fish advisories may help reduce problems, but reducing mercury emissions from sources such as the chlorine-production industry is a real key to long-term environmental health--for us and the fish!