Thursday, June 24, 2010

toxins in sperm whales

Toxins found in whales bode ill for humans

This is based on a news piece I read in Yahoo news (toxins&whales). I'm not sure why is this such a shock. It is well known that animals & fish that feed on other species of animals will accumulate the toxins that their prey have eaten. And as you go further up the food chain the toxins accumulate to higher concentrations (it was noted that sperm whales eat sharks!). This is why pregnant women, children & other susceptible groups shouldn't eat salmon, mahi mahi and similar fish. See: for information about this (I tried to find the information at the USDA or EPA websites but found it difficult to do so). And given the fact that ocean currents will carry waste & debris from one end of the earth to another (see: it shouldn't be that much of a surprise that Artic whales have high levels of toxins.

I also think an explanation of one of the statements by Roger Payne, who headed the study, is needed:
"the concentration of chromium found in whales was several times higher than the level required to kill healthy cells in a Petri dish"

Sometimes you can't make the jump from what is observed in animals to what you would expect to observe in cells in culture. Healthy cells in Petri dishes aren't normal cells; although scientists use them as if they are to do their experiments. These are cells that have been transformed (changed) to become immortal so that scientists have time to do their research (normal cells from humans or other mammalian species have a limited life span in culture). To become immortal the cells have acquired mutations or have oncogenes (cancer causing genes) inserted into their genomes - many of the changes that are associated with immortalization are not known and there may be other mutations that may not be related to immortalization but will contribute to how the cells act in culture.

Take home message: (1) don't take science news articles at face value - the reporters writing these articles often don't have the background to ask the right questions or see the 'big picture'; and (2) take care in choosing the foods you eat. I have found the book, "What to Eat" by Marion Nestle to be quite informative. She also has additional information at her website

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