A correction on lead

I just noticed that in my last discussion of lead in eggs I failed to mention that my calculations were off by a factor of 10 - as the chemist wrote, "Your egg results are 0.2 to 0.4 ppm (ug/g) not 2-4 ppm! Therefore 0.4 ug/g from a 18 g egg would be 0.4ug/g * 18g (g canceled out) equal to 5.8ug (micrograms) per egg yolk." For an egg with 0.2/ug/g that would be 2.9 ug/yolk, I think. (Anyone with more knowledge of microchemistry than me is welcome to check my figures!). According to the FDA, the average adult takes in 2.5 ug of lead per day from dietary sources (1994-1996), compared to 38 ug per day, on average, between 1982 and 1984 and presumably before (!). (That's because lead was removed from cans). In Australia, the PTTIL (provisional tolerable total intake level) - the amount safely consumed per day - is less than 75 ug/day. I believe the US PTTIL is similar. (This level was determined in order to figure out how many oysters people could safely eat a day).

So I guess what this all means - to me, anyway - is that it's OK if we eat an egg from our chickens once in a while. We shouldn't eat more than seven a day. The fact that my blood test for lead came back "zero" after many months of eating our eggs confirms that. For kids it's still a different matter, though - kids don't get rid of lead in their bodies as well as adults and their tolerance is much, much lower.