Backyard Chickens, Eggs, and Lead
Thank you Jennifer, who emailed us to share her experiences with detecting lead in their backyard chickens' eggs.
For me, this all started with Tamara Rubin's piece in the Portland Tribune (http://www.portlandtribune.com/opinion/story.php?story_id=123801660877902600). A friend (also with chickens) pointed it out to me and we wondered if we should be concerned. Honestly, it had never occurred to me that my chickens might be consuming lead, but the article made sense. Since my daughter was up for her 4-year checkup, I had her tested for lead (for the first time) and I got a test too. My test came back as a "1" (the lowest possible) and hers came back as a 3. According to someone I spoke to from the Portland Lead Line, most kids average between one and three. The official "level of concern" is 10, although there is much argument over whether this is too high (most people think it is). Therefore, a 3 is cause for mild concern and further investigation (she shows no signs of lead poisoning; most signs don't show up until levels reach higher than 10, but there are still potential long-term effects from low lead levels).
So I had my backyard chicken eggs tested. The results came in today - .2, .3, and .4 parts per million. These levels are very similar to the eggs tested in the only academic study I'm aware of (http://jvdi.org/cgi/reprint/15/5/418.pdf). Their highest egg yolk lead level was also .4 ppm (400 ppb), which lead them to conclude that "Eggs and chicken tissues containing significant concentrations of lead are a potential human health hazard, especially to young children. Repeated consumption of contaminated eggs from a family owned flock could provide a continuing dietary source of lead." As a control, they tested eggs of chickens that had not been exposed to lead paint, and their levels were much lower. Lead does not naturally occur in chicken eggs, so these levels *do* represent a problem. (For comparison's sake, the FDA limit for lead in "candy consumed frequently by children" is .1 ppm).
We live in a house in NE Portland. The house was built in 1920 (so plenty of lead paint), and it was completely renovated about 7 years ago - I suspect not using the safest lead paint removal methods. In addition, our neighbor's garage backs onto our back yard. I tested the peeling paint on this ancient garage and it clearly showed the presence of lead. I have since fenced off the area to my chickens, so I wonder if their levels will eventually drop.
I thought that other moms with chickens would be interested in these results. I want to make it clear that I am very "urban chicken positive" and am not suggesting that we ban backyard chickens and replace them with corporate egg farms. (On various blogs there seems to be a perception that any slight of backyard chickens must be driven by agribusiness interests). I love my three hens - Dolley, Martha & Abigail. I am planning to test the soil for lead to find out if it is concentrated in certain parts of my yard that I could fence off or remediate. Meanwhile, I will be buying my eggs at New Seasons (I'm not a shill for them either) and occasionally making egg white omelettes and meringues (lead does not concentrate in egg whites). After I remediate, I'll test our eggs again. I should note that if you do have lead in your eggs you should not compost the egg shells because lead concentrates in the egg shells and in the yolks. (And whatever you do, don't eat your girls!).