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Free range eggs contain a little something extra: pollutants

June 16, 2010 |  1:16 pm

Here’s some disconcerting news for health-conscious eaters who favor eggs from free-range hens: A Taiwanese study found that the eggs contain much higher levels of industrial pollutants than eggs laid by caged hens.

Freerange The researchers focused on two types of pollutants, polychlorinated dibenzo-p-dioxins and dibenzofurans (known collectively as PCCD/Fs), which are released into the environment by municipal waste incinerators, factories and other industrial sources. A report from the International Program on Chemical Safety says the chemicals have caused cancer, liver damage, problems with the skin and nervous system, reproductive problems and other undesirable effects in animals.

The researchers collected 60 free range eggs from farms in southern Taiwan and compared them with 120 eggs from caged hens that were purchased throughout the country. Then they measured the levels of 17 kinds of PCCD/Fs.

For the free range eggs, the levels ranged from 6.18 to 41.3 picograms per gram of lipid, with an average value of 17.5 pg/g. Levels for the caged eggs ranged from 2.85 to 19.8 pg/g, with an average value of 7.65.

The researchers also calculated the toxic equivalency quotient (TEQ) for both kinds of eggs using a system endorsed by the World Health Organization. The levels for the free range eggs were 5.7 times higher than the levels for the caged eggs.

In addition, 17% of the free range eggs had levels that European regulators have deemed unsafe for consumption. All of the caged eggs were easily in the safe zone, the researchers found. The results were published in the latest edition of the Journal of Agricultural and Food Chemistry.

The researchers believe the free range eggs have more contaminants because they are found in the environments where free range hens roam. Studies have found the chemicals in “feedstuffs, soil, plants, worms and insects,” they wrote. Their own measurements of dirt from free range farms persuaded them that soil contamination is at least partly to blame.

The problem probably isn’t limited to Taiwan. Scientists have also found the same trend in the European Union, and one study found that about 10% of free range eggs exceeded the safety limit set by regulators there.

“The issue of contamination in free range eggs could be a global issue, and more research should be done to identify the factors from the external environment that influence and modify the PCDD/F levels in eggs from free range hens,” the authors wrote.

In case you were wondering, their research was not sponsored by the commercial egg-laying industry. The scientists had grants from the National Science Council of Taiwan and the Taiwanese Ministry of Education.

— Karen Kaplan

Photo: These free-range chickens seem to be enjoying their time outdoors, but with dioxins lurking in the environment, it may not be good for them – or us – after all. Credit: Steve Osman / Los Angeles Times

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Comments (43)

@Everyone Raging

"Booster Shots
Oddities, musings and news from the health world"

Not everything has to be some deep, life changing investigative report.

@Everyone Raging

"Booster Shots
Oddities, musings and news from the health world"

Not everything has to be some deep, life changing investigative report.

Any studies done in the U.S? Taiwan is a little out of my way to pick up a dozen eggs.

ummm, given that "Free Range" in the US means only that the barn door is open for a few weeks during a chickens' life, this means nothing. Especially since the buildings chickens are raised in are huge, crammed with poultry and chickens are afraid of the unknown. If they're not introduced to the outdoors young, they don't go there. So your mythical Free Range hen rarely - if ever - sets a single scaly foot outside of the building it's raised in.

Look at the individual area, do the studies on where the hen actually is, then you'll have something to talk about.

In the meantime, realize that your "free range hen" has never breathed air that wasn't filled with fecal matter and ammonia, and get over it.

Wow, they collected 60 eggs? That's not a research study, LA Times. You shouldn't even report on it... Who's not to say that ONE farm had contamination? Not an empirical study... this is garbage.

Also, one gets more nutrients and "life" when the food is happy and well cared for during and up to slaughter. Corn feed is horrible for all of us... very little nutrients in the caged birds we eat. No one ate that much corn until it was gov. covered the cost. Now it's in everything.

That's why I'll take my pollutants (if that's even true for us) and eat the healthier, happier egg. :)

I'll remember this the next time I get my free range eggs from Taiwan.

So . . . the moral is to avoid eggs from Taiwan?

Or maybe the moral is not to tend animals in polluted areas?

But this is terrible journalism to simply claim that free-range eggs are worse for you than caged eggs. Shame on you Karen for valuing page views over intelligent journalism.

Thank you Barry. I share your view.

"which are released into the environment by municipal waste incinerators, factories and other industrial sources."

So why is this not framed as a referendum on the incinerators, factories, etc., showing need for tighter pollution controls, instead of being the critique of free range practicing it is? Seems to amount to blaming the victim.

In fact, if I was an egg farmer and these pollutants contaminated my crop leading to sales loss given this finding, I would consider suing the pants off of someone.

The author obviously has never been to Taiwan. That entire country, even the rural areas, is covered in industrial pollutants. The urban areas either do not have or do not enforce vehicle emissions regulations, and the entire country lacks sewage systems. Anybody who has traveled to Taiwan would EXPECT food and water.

How about we clean up the air and soil rather than confining more of these seriously abused beings in factory farming "concentration camps". Who issued the grants?

While this story might be very legitimate and I certainly don't challenge the findings, my concern is that Americans reading the story might assume that ALL free range eggs are contaminated. And that's not a safe assumption to make.

I traveled to Taiwan many times in the 90's and even then, they had significantly more factories using chemicals in a populated area than we do here. Historically, they have not cared for their environment, people and food system in the way that we have here.

We buy our eggs from local providers, many of whom we know the farmer and are confident about the environment and practices used to get eggs to the market. I would encourage readers to do look at labels, understand where your food comes from and make the best choice for your family.

It is truly amazing, those who comment so obviously bring their own prejudices to the party. " Happy Eggs" ?? The nutrient value of eggs varies with diet and genetics, not with housing. Those with closed minds only see the evidence they want to, not that which is presented. This scientific study may have the same level of validity as those which favor free range or cage free over a more protected environment.

Who needs to read the Onion when the L.A. Times writes articles like this?

agree by local eggs, why are we buying eggs from Taiwan??

Hey, any report made from US Farms? I agree, why scare people with your silly, broad headline statements.

I think the "organic" commenters are a little too defensive, which is why people in the center with no stake in the battle can't get reliable facts from either side.

No, this study wasn't conducted in the US. But why exactly would the US, one of the biggest polluters in the world, be free from the findings in Taiwan and Europe? Articles like these are important because they lead us to conduct study our own food supply. Our food just might be safer, or not.

I just don't think California is vastly superior to the way they raise chickens in Europe or Taiwan.



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