The bone of a 20th century human has 1000‐fold more lead than that of a preindustrial human. Current sources of lead exposure to humans now result from soil, food, water, tobacco smoke and electronic cigarettes, lead‐based paints in and around older construction, and water pipes, to name a few.
Natural skeletal levels of lead in Homo sapiens sapiens uncontaminated by technological lead
^ bone lead in american indians skeletons from 700 & 1000 years ago vs levels in modern humans
(this study was before the ban on leaded gas - but i bet it's still many multiples above):
a mean natural body burden of 40 micrograms Pb/70 kg adult Homo sapiens sapiens, uncontaminated by technological Pb. This value is about one-thousandth of the mean body burden of 40 mg industrial Pb/70 kg adult American today, which indicates the probable existence within most Americans of dysfunctions caused by poisoning from chronic, excessive overexposures to industrial Pb.
A follow up study in canada assessing bone lead in 2010
ShieldSquare Captcha In 2010, an average person aged 57 years had a bone lead level approximately 1/3 less than their bone lead level age 40 years in 1993.
^ so can assume now reduced a lot compared to the 1991 study. but obviously completely depends on the individual (not just gas exposure). and it was so crazy high back then that even a massive reduction might still be too much.
Health effects of lead result from its ability to form strong bonds with proteins, and its interference with zinc and calcium (both divalent cations) dependent functions, particularly antioxidant functions and cellular signaling.22, 23, 24, 25 The interference with antioxidant function is of particular relevance. Lead directly and indirectly inhibits glutathione synthesis and function, and depresses superoxide dismutase activity, a zinc metalloprotein in humans.
Exposure to lead also results in epigenetic changes by inducing histone modifications. The half life of lead in cortical bone is approximately 30 years [7 - 26 years]. accumulation in bone remains as a continuous internal source of lead to the vascular endothelium and other tissues as it leaches out over decades of life.
The study found individuals with blood lead levels of 20 to 29 µg/dL experienced a 46% increase in all‐cause mortality compared with those with blood lead levels of <10 µg/dL. 20 mg/dl = 0.2 parts per million PPM
In NHANES III (1988–1994), patients with the highest tertile of blood lead (≥3.62 µg/dL) compared with the lowest tertile (<1.94 µg/dL) experienced a significantly higher risk of death during follow‐up. The increased risk was 25% for total mortality, 55% for cardiovascular mortality, 89% for myocardial infarction, and 151% for stroke
Signs and symptoms of chronic exposure include loss of short-term memory or concentration, depression, nausea, abdominal pain, loss of coordination, and numbness and tingling in the extremities (Patrick, 2006). Fatigue, problems with sleep, headaches, stupor, slurred speech, and anaemia are also found in chronic lead poisoning (Pearce, 2007). Children with chronic poisoning generally show aggressive behaviour and refuse to play.
Lead toxicity is an important environmental disease and its effects on the human body are devastating. There is almost no function in the human body which is not affected by lead toxicity.
Mind blown i'm only just finding out about this now. This ***t should be illuminated way more for the general public.
We probably want to make sure we're in the <10µg/dL / 0.1 parts per million group at the very least if not much lower .. and this is just for 1 of the common toxic metals
How do blood levels relate to tissue levels? it varies but 0.1 PPM in blood = what range of PPM in nails or hair for example? i'd guess the "acceptable" ppm in tissues would be higher but not sure -
this mentions high levels in hair being 20 ppm Lead concentrations in human tissues "Hair and nails were found to contain relatively high concentrations of lead, approximately 20 ppm" Lead concentrations in human tissues <- various tissue samples in this group, 0.22ppm in blood was paired with 18.44ppm in hair and 9.4 ppm in nails in men. in women 0.14ppm in blood was paired with 19.07ppm in hair.
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