Tuesday 12 May 2009

Science & Environment: How Sea Shells Clean Water

Oyster Shell Mountains
Image by Ari Brown

Recently, I read a news article from Discovery News and it unveiled the magic that unwanted seashells can actually help us clean up the heavy metal in the water and thus partially solving the aftereffect of the human pollution to waters.

I wonder if the government knows anything about this.

In brief, the chemical that made up the seashells, aragonite (a form of calcium carbonate CaCO3), can swap out the calcium for the heavy metal pollutants and locking them into solid form, thus not floating around in the water anymore.

I was both totally stunned and impressed by the art of work by the nature. That to me, it seems like every problem has a potential method or remedy to solve the problem. I would like to believe that there are cures for every environmental problem in this world, and it is up to us to find it and apply it.

Tuna killing, is it worth it?
Image from The Guardian
Do you like to eat salmon?I like it, especially from Japanese sushi restaurants, but do you know that most of the deep water fish that we eat nowadays are polluted by heavy metals such as Mercury (Hg)?

Mercury, according to Wikipedia, has a tendency to concentrate in the body of fish and shellfish often in the form of methylmercury, which is highly toxic. Species of fish that are high in the food chain, meaning bigger and eats smaller fish, such as shark, swordfish and albacore tuna, contains higher concentration of mercury than others. So, anybody still wants to eat sharkfins or swordfish in Japanese restaurants?
According to the above news article, "said McLean, heavy metals have accumulated in the environment and animals, which are more likely than humans to feed off plants and insects, remain at risk."
Another article on Medical News Today dated on 04th June 2008, said that the level of Mercury of the salmon in the wild "was three times higher than the farmed salmon".
A high dose of mercury exposure or consumption can cause Mercury poisoning. Toxic effects include damage to the brain, kidney, and lungs. Mercury poisoning can result in several diseases, including acrodynia (in children characterized by pain and pink discoloration of the hands and feet.), Hunter-Russell syndrome, and Minamata disease (symptoms include ataxia, numbness in the hands and feet, general muscle weakness, narrowing of the field of vision and damage to hearing and speech. In extreme cases, insanity, paralysis, coma and death follow within weeks of the onset of symptoms.).

I wish that this mercury problem can be solved with natural means, but so far, there is none. So take care of yourself and mind the food that you eat. Think about the danger before consuming.