Greenland, the largest island in the world not considered its own continent, lies above the Arctic Circle with the exception of its Southern tip. Ice—the Greenland Ice Sheet—is everywhere but is rapidly becoming a major contributor to sea level rise as it melts because of climate change. Now, a new study shows that the resulting freshwater (or meltwater) runs off to the ocean taking along an unexpected and toxic companion—mercury, a chemical that when transformed into methylmercury bioaccumulates and biomagnifies in fish, shellfish, and animals that eat fish, causing nervous system damage and other deleterious effects in humans and wildlife.
A guest post by Julie P. Avery, Nicole Misarti, Todd M. O’Hara, and Lorrie D. Rea
Do you like fish? Have you heard warnings from the FDA about consuming predatory fish such as tuna, swordfish, and shark due to high mercury? Fish are a healthy food and an excellent source of lean protein, healthy omega-3 fats, vitamin D, iron, selenium, zinc, and iodine. Fish provide all these nutrients, which are essential for human and animal health. Marine mammals in Alaska, like Steller sea lions and northern fur seals, thrive on a diverse fish diet. But what about the mercury? Since we eat some of the same fish as seals and sea lions, we can study them to understand how mercury might affect humans.
Coastal and Arctic communities are especially vulnerable to the effects of mercury contamination due to their dependence on fish and marine resources for food and sociocultural needs. According to the World Health Organization, mercury is one of the top 10 contaminants of concern for human health.
Moving in an endless cycle, mercury goes from the atmosphere to soil, water and sediment, and then back to the atmosphere. While moving around, mercury changes to its various forms, often becoming the highly toxic and bioaccumulative methylmercury, the type that builds up in living tissue and increases in concentration up the food chain – including the food we consume. Continue reading →
In October 2013, the Minamata Convention on Mercury brought renewed attention to a major global pollution problem known to result in the contamination of seafood and, subsequently, in a variety of health problems in people that consume it. Designed to limit mercury use and emissions internationally, the Convention is only a first step in limiting mercury pollution. Continue reading →