 Children in approximately 4 million households in the United States are being exposed to high levels of lead. Despite the dramatic decline in children's blood-lead concentrations over the decades, lead toxicity remains a major public health problem, and not just for children. Yes, lead is a devastating neurotoxin, starting with learning disabilities and attention deficits in children starting around a blood-lead level of 10, micrograms per deciliter, which is when you start seeing high blood pressure and nerve damage in adults. But the blood levels in American adults these days is down around 1, not 10, unless you work or play in an indoor firing range where the lead levels in the air are so high, more than half of recreational target shooters have levels over 10 or even 25. In fact, even open-air outdoor ranges can be a problem. Spending just two days a month at a range may quadruple blood-lead levels up into the danger zone. But what if you don't use firearms or live in a house with someone who uses firearms? The lead levels can be so high, the CDC advises those who go to shooting ranges shower there, change into clean clothes, don't mix clean clothes with contaminated clothes, don't bring your shoes home, etc. Even if none of that applies and your blood levels are under 10, there's still some evidence of increased risk of hand tremors and high blood pressure and kidney damage and other issues. But come on, just one? What if you're down around a blood level of one, like most people? We didn't know until this study, which found that blood-lead levels, even in the range currently considered acceptable, are associated with an increased prevalence of the painful arthritis known as gout. They found blood levels as low as approximately 1.2 can be associated with increased prevalence of gout, which is close to the current American average. So this means quote-unquote very low levels of lead may still be associated with health risks, suggesting there's no such thing as a safe level of exposure to lead. Okay, but where is the lead coming from? Lead only circulates in your body for about a month, so if you have lead in your bloodstream, it's some ongoing exposure. But most adults don't eat peeling paint chips. There's no more leaded gas on the road. I mean, there are specific foods, supplements, and cosmetics that are contaminated with lead, and I have videos coming up on all those topics. But for most adults, the source of ongoing lead exposure is from our own skeleton. Remember how I said lead only lasts around about a month? Well, where does it go? It can get deposited in our bones. More than 90% of the total body lead content resides in the bone, where the half-life is not a month, but can be decades long. So half or more of the lead in our blood represents lead from past exposures just now leaching out of our bones back into our bloodstream. And it is this gradual release of lead from the bone that can serve as a persistent source of toxicity long after leaded gas was removed from the pumps for those of us who were around back before the 80s. So the question to where is the lead coming from is like, Po goes, we've met the enemy and he is us, or like that horror movie, the call is coming from inside the house. The amount of lead in your bones can actually be measured and higher levels are associated with some of our leading causes of death and disability, from tooth decay and miscarriages to cognitive decline and cataracts. Much of the lead found in adults today was deposited decades ago, thus regulations enacted in the 1970s may have been too late for many of us. But at least things are going in the right direction now. The dramatic societal decreases in blood lead in the US since the 1970s have been associated with a 4 to 5 point increase in the average IQs of American adults. Particularly provocative question then is whether the whole country suffered brain damage prior to the 1980 decreases in blood lead. Was the best generation really the brain damaged generation?