What a scary year for news on the egg front.  First, widespread Salmonella contamination was found in eggs from a factory farm supplying stores nationwide.  And now we hear of dioxins detected in free-range eggs from a study by Taiwanese researchers.  What is someone to do – spend thousands of dollars analyzing their every food source for pathogens and toxic chemicals?

As the stories of Salmonella-contaminated eggs unfolded, I felt relief that I spend a bit extra for organic, free-range eggs, especially since both of my nephews were struck this summer with severe Salmonella-like symptoms possibly linked to their consumption of cheaper eggs.

But then we get the news that eggs of chickens allowed to roam outdoors contained up to 5 times the concentrations of dioxins as eggs from chickens kept caged.  Now what?

Where does the dioxin in these eggs come from?  There are many sources for these chemicals but combustion of wastes containing chlorinated plastics (e.g. vinyl/PVC) and paper bleaching are two important ones.  Plumes of contaminated smoke from incinerators and wastewater from paper producers flow into the environment and ultimately contaminate the fatty tissues of animals we consume.

So how do you avoid toxic pollutants like dioxins without resorting to factory farm products that may have other problems, like Salmonella?  As I mentioned in a previous blog, location is everything when it comes to environmental contamination of animal products.  I haven’t seen a study yet on geographic distribution of dioxins in eggs but they should mirror contamination of beef and dairy products.  These studies indicated that products from animals reared on the coastal western U.S. are the safest and those from animals reared downwind from incinerators or industrial regions the most contaminated.

Bottom line, the only way we’ll clear our food supply of toxic chemicals is to stop producing them and clean up hotspots on land and in our rivers.  For now, the best way to avoid exposure to contaminants like dioxins is to minimize consumption of fatty animal products.

Reference: J-F Hsu, C Chen, P-C Liao, J. Agric. Food Chem, 2010, 58:7708-14.