As a former analytical chemist, we can detect most metals down to the parts per trillion or lower.
So the more sensitive our instruments get the “more kids have lead”.
With sufficiently sensitive testing you’d probably find lead in 100% of people.
It's possible that more sensitive instruments will allow us to eventually conclude "this small amount X of lead is safe to have ...". But it makes sense to take this seriously. We know lead is bad and we know lots of environmental exposure to lead exists.
Lead exists in the environment. It would be impractical to impossible to eliminate it entirely from the blood streams of most people. However certain areas have extremely dangerous concentrations such as dirt near major roads/old buildings, water in certain areas, and lead paints.
Lead pipes are an interesting one where it is simply impractical to replace all the pipes and remove lead in old cities. Hence as long as the calcification holds there is no action on the small amount of lead which leaks into the pipes.
The problem is that pipe ownership in a domestic home is the property of the homeowner, and there's no political will to do that kind of massive wealth transfer from the public coffers to the improved infrastructure of millions of individual properties. But while it wouldn't be inexpensive, it's on par with other expenditures the federal government makes for federal projects.
What we really want to know is: how big of a deal is this really?
We used to use lead based pesticides at the dawn of the 20th century, if you eat any food grown in the midwest you are exposing yourself to reasonably large quantities of lead.
If there's no science that says "one atom of lead anywhere in your body is bad", then saying "detectable" is meaningless.
I mean, if you said "we found a detectable number of bullets in half of children", now that would be bad.
*Another poster noted this level.
It would be meaningless on that case too.
Also meaningless is saying that 2% of the kids have a high level of lead, without saying what "high" means.
Oh, that's simple - it's defined as above the 98th percentile.
(I kid, I hope...)
But if only 2% of children have lead levels that were originally defined based on the worst 2.5%, that's a 20% reduction, so great news!?
[1] https://www.cdc.gov/nceh/lead/prevention/blood-lead-levels.h...
Did they find a problem? An improvement? Nothing? Nobody can tell by reading it alone.
They defined these blood lead levels:
* "detectable": ≥1.0 μg/dL
* "elevated": ≥5.0 μg/dL
They found that:
* 50.5% had "detectable" levels (50.4%-50.6% for the 95% CI).
* 1.9% had "elevated" levels (1.8%-1.9% for the 95% CI [wait, how is the reported amount the same as the upper limit of the CI?]).
The paper does start out saying:
> No safe level of exposure to lead has been identified.
Which I believe to be true, though it's not the same as "no level of exposure to lead is safe". I would be interested in what levels are known to be unsafe. Is 1.0 μg/dL known to be unsafe, or just not known to be safe?
It's pretty clear we should be working to reduce lead exposure, especially in children, but it's also true that "detectable amounts" and "harmful" aren't the same thing. The former clearly varies with our technology and the other remains constant (and isn't, afaik, known to be 0).
I'm curious. If there's lead in the water, the air, the soil, the food we eat, is zero even possible? Is there a baseline "side effect of living on Earth" level, even if it's very slight?
The death rate of being human is 100%. Every five minutes there's some new paper or study letting us all know why we should be afraid of something new.
I'm not saying this particular study is necessarily scare-mongering, but good grief is it tiring to see this stuff all day every day, without any scale of risk for context.
Recent discussion: https://news.ycombinator.com/item?id=27634549