The Effects of Low-Level Lead Exposure in Adults

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

“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 down 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 are 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 “2 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 to 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 1? What if you’re down around a blood level of 1, like most people? We didn’t know, until this study, which found that “[b]lood 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 “very low levels of lead may still be associated with health risks,” suggesting “that there is 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 exposure” 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 of where is the lead coming from is like Pogo’s: “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 U.S.] since the 1970s” have been associated with a four- to five-point increase in the average IQs of American adults. “A 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?”

Please consider volunteering to help out on the site.

• Lamphear, BP. Childhood lead poisoning prevention: too little, too late. JAMA. 2005 May 11;293(18):2274-6.
• Krishnan E, Lingala B, Bhalla V. Low-level lead exposure and the prevalence of gout: an observational study. Ann Intern Med. 2012 Aug 21;157(4):233-41.
• Angle CR. Pitfalls of correlation of childhood blood lead and cognitive development. J Toxicol Clin Toxicol. 2002;40(4):521-2.
• Kaufman AS, Zhou X, Reynolds MR, Kaufman NL, Green GP, Weiss LG. The possible societal impact of the decrease in U.S. blood lead levels on adult IQ. Environ Res. 2014 Jul;132:413-20.
• Beaucham C, Page E, Alarcon WA, Calvert GM, Methner M, Schoonover TM; Centers for Disease Control and Prevention (CDC). Indoor firing ranges and elevated blood lead levels - United States, 2002-2013. MMWR Morb Mortal Wkly Rep. 2014 Apr 25;63(16):347-51.
• Goldberg RL, Hicks AM, O'Leary LM, London S. Lead exposure at uncovered outdoor firing ranges. J Occup Med. 1991 Jun;33(6):718-9.
• Leech TG, Adams EA, Weathers TD, Staten LK, Filippelli GM. Inequitable Chronic Lead Exposure: A Dual Legacy of Social and Environmental Injustice. Fam Community Health. 2016 Jul-Sep;39(3):151-9.

Image credit: Stockdevil via 123RF. Image has been modified.

• ADHD
• arthritis
• blood pressure
• cataracts
• CDC
• children
• cognition
• dental health
• gout
• heavy metals
• high blood pressure
• hypertension
• industry influence
• kidney function
• lead
• miscarriage
• mortality
• safety limits