Salmonella in Caged Eggs vs. Dioxins in Free-range… Two Ends of the Egg Dilemma

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.

Avoiding the Fumes: A Green but Unhealthy Commute

(Paco Ayala, photoxpress)

About five years ago I spoke to a woman who was concerned about the risks of her boyfriend’s bicycle commute to work in one of the most progressive cities in the country – Portland, OR.  I loved that we lived in a city that promoted green commuting by installing bike lanes and mapping out preferred routes.  But the reason we were talking was that his cycling among the cars was taking a toll on his health.  A nonsmoker, he was beginning to suffer from a hacking cough possibly brought on from breathing exhaust fumes during his commute.

She asked me what he might be able to do to protect his health and I suggested that he wear a respirator to reduce his exposure to toxic particles and fumes.  She laughed and replied that he’d be more likely to just tough it out.

I was reminded of this exchange when I read a recent article by a Belgian researcher, Dr. Int Panis¹.  His research team determined that bicyclists inhaled a greater volume of air and thus exhaust during their commute than people driving their cars.  And bicyclists were more likely to take longer to complete the journey than drivers, resulting in exposure to exhaust for a longer period of time.  The combination of these and other factors resulted in a 5 to 9 times greater inhalation of exhaust particles by bicyclists than car drivers during their commute.

It’s a shame that the pioneers of greening our commute are the most highly exposed to toxic exhaust, which has been linked to increased cardiovascular disease, asthma, and cancer.  It is my hope that we will soon shift to vehicles and transit modes that are much less polluting, making daily trips along our roadways less dangerous to our health.

(Jean Cliclac, photoxpress)

In the meantime, following these strategies could reduce your exposure if your commute or exercise routine leaves you running, walking, or bicycling in a cloud of traffic exhaust:

• Pick a less-traveled route: avoid primary traffic arteries by taking side roads or heading through the park where possible.
• Shift your timing away from peak commute hours: air quality is best before the morning commute.
• And if you can’t steer clear of it, considering braving the Darth Vader look by wearing a respirator that filters both fine particles (<2.5 microns) and fumes (carbon filter).  Note that respirators aren’t effective for guys with beards.

Reference

¹Int Panis, L., B. de Geus, G. Vandenbulcke, H. Willems, B. Degraeuwe, N. Bleux, V. Mishra, I. Thomas, R. Meeusen (2010).  Exposure to particulate matter in traffic: A comparison of cyclists and car passengers.  Atmospheric Environment, Vol. 44:2263-2270.

“What’s in the Beef?” Are Organic Beef and Dairy Products Free of Environmental Contaminants?

I was recently asked whether organic beef would be a good choice to avoid exposure to toxic chemicals.  It was an excellent question because our consumption of products from animals high on the food chain is one of the key ways we are exposed to fat-soluble contaminants such as dioxins, organochlorine (OC) pesticides, and polychlorinated biphenyls (PCBs).  And because it takes decades to clear these chemicals from our bodies, the best approach is to avoid them in the first place.  So wouldn’t consuming organic rather than conventionally raised beef reduce your exposure to toxic chemicals? The answer to this question is – not entirely.

There are several good reasons for switching to grass-fed organic beef products from those of conventionally raised animals.  For example, beef from grass-fed cattle contains a healthier ratio of omega 3 to omega 6 fats.  And, conventionally raised cattle may be exposed to pesticides in their feed.

However, switching to organic beef will not reduce your exposure to the contaminants listed above because these chemicals are present in air pollution worldwide and are deposited on both grasses and grains that provide food for cattle.  As cattle consume large quantities of these crops over their life span, they accumulate fat-soluble toxic chemicals into their fatty tissues, a process called bioaccumulation.

Not all cattle are equally contaminated.  Although air pollution is transported to all corners of the earth, some areas are more contaminated than others and cattle’s toxic body burdens tend to reflect contamination in their local environment.  For example, butter collected from 23 countries across 5 continents was most contaminated in areas where these chemicals were in current use, such as India and Mexico, and less so in the U.S. and parts of Europe, where their use has been discontinued but where the environment was still contaminated from past use (ref 1).

Just as it is the fat in beef and butter that introduces these fat-soluble chemicals into your diet, don’t forget about other products that get their fat from cattle, such as cheese, milk, and yogurt.  If you love beef or dairy products, one way to reduce your exposure to these contaminants is to choose products with the lowest fat content for regular consumption and save the higher fat delicacies (e.g. butter and brie) for the occasional treat.  Also, discarding the fats released when you cook meat reduces the amount of these contaminants that you consume (ref 2).

So, how do you shop for a cleaner source of meat and dairy products?  The research on butter contamination discussed above demonstrated that the most highly contaminated butter was collected in areas located near urban and industrial sources.  In the U.S., which has a legacy of environmental contamination, east coast butter samples were found to be more contaminated than those purchased along the west coast, which receives air that has traveled thousands of miles across the Pacific Ocean and had time to be cleared of many contaminants.

Bottom line: choosing lower fat organic beef and dairy products from cattle reared in cleaner environments, such as rural areas along the west coast of the U.S., is the best option for reducing your exposure to fat-soluble toxic chemicals.

References:

¹Kalantzi, O. I., R. E. Alcock, P. A. Johnston, D. Santillo, R. L. Stringer, G. O. Thomas, and K. C. Jones (2001). The global distribution of PCBs and organochlorine pesticides in butter.  Environ. Sci. Technol. 35:1013-1018.

²Petroske, E., R. G. Zaylskie, and V. J. Feil (1998).  Reduction in polychlorinated dibenzodioxin and dibenzofuran residues in hamburger meat during cooking. J. Agric. Food Chem. 46:3280-3284.

Stay tuned for blogs on reducing personal exposure to household and environmental toxics

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