I was interested enough to follow the link the OP entitled
&quot;Across America, 535,000 children ages 1 through 5 suffer lead poisoning, by C.D.C. estimates.&quot;<p>Here it is for convenience:<p><a href="http:&#x2F;&#x2F;www.cdc.gov&#x2F;mmwr&#x2F;preview&#x2F;mmwrhtml&#x2F;mm6213a3.htm" rel="nofollow">http:&#x2F;&#x2F;www.cdc.gov&#x2F;mmwr&#x2F;preview&#x2F;mmwrhtml&#x2F;mm6213a3.htm</a> (2013)<p>As far as I can tell, the CDC regularly tests some children in a malnourished nutrition program (not a random sample of all children), with sample sizes in the N=1600 to 1800 range over several years.  They divided that data into several cohorts, and over time the incidence of children above the threshold reported has decreased in all factor categories, so that by the 2010 cohort it was one third what the incidence was in the 2000 cohort.<p>Now I didn&#x27;t do more than skim the article -- did I miss a smoking gun?  Or am I looking at link bait by a journalist?<p>I do not wish to belittle whatever crisis the article is about,  whatever it is, but its links backing up the alarm are not, in fact alarming.<p>&quot;Lead poisoning in poor children decreased 3x over the Augties, CDC said 3 years ago&quot;<p>The author seems to have done a deep dive and found some alarming numbers.  I wonder if his Iowa data are from the Quad Cities area -- a region historically known for lead mining.  I can well imagine that lead poisoning has a strong environmental and industrial component, and that some places are worse than others just because of the soil.  That is certainly true of exposure to radon gas in the home, for example.