People should realise they are at risk of exposure to higher levels of lead than recommended.

The results of their study, published in Environmental Research in November 2018, found that 94 percent of backyard chicken owners regularly ate eggs. And nearly all the eggs sampled—98 percent of them—contained detectable concentrations of lead. The lead appeared to primarily come from dirt in the chickens’ coops, which is a finding consistent with the few other studies of urban chickens in New York, Belgium, and Australia.

This is because lead in fuel was legal until just a few decades ago. This means that for 70+ years, any houses near roads will have lead contamination in the soil.