Lead 24 August 2009
Lead poisoning remains a serious health risk particularly for expectant mothers and children. The World Bank has identified lead poisoning as the number one environmental disease among children in the industrialised world. The US Center for Disease Control ranks toxic metals (especially arsenic, lead and mercury) as the number 1 environmental health threat to children. With the industrialisation of the world, the environmental amounts of toxic metals have markedly increased. Continued exposure in Australia occurs from:
- old paint from buildings built prior to 1970
- soil contaminated from previous use of lead petrol
- coal burning
- industrial exposure — furniture restoration, car batteries, radiators
- plumbing — new taps can contain 4.5% lead and old taps may contain more
- some food cans
- lead smelters
- calcium supplements made from bone meal or oyster shells
- cigarette smoke
- in areas with historical contamination of the soil by heavy metals, house dust remains a persistent source of exposure even decades after the cessation of industrial activity.
Lead is stored in bones and teeth. A study published in the April 1979 edition of the New England Journal of Medicine showed that the average bone of today carries over 1000 times more lead than bones of humans living 400 years ago. Without continued exposure, it takes seven years to reduce the body burden of lead by half (the half life). Stored lead is mobilised during pregnancy and easily crosses the placenta, interfering with the developing brain. This can result in learning disabilities, decreased intelligence, irritability, attention deficit disorders and hyperactivity. A study published in the April 2003 edition of the New England Journal of Medicine has shown that lead blood levels far below the accepted “safe” cut off level of 10 mcg/dl effects mental development and IQ. Similarly, a study published in the November 2007 edition of the online journal Environmental Health Perspectives has shown that there are no safe levels of lead and the higher the lead levels, the lower the IQ.
Authors of a 1995 study on lead and reading disability published in the journal Medical Decision Making concluded that “chelation of the 1.4% of preschoolers whose blood lead levels are 25mcg/dl (2.21 micromol/l) or higher could prevent more than 45000 cases of reading disability and save more than $900M/year in remedial education costs.”
Lead has also been shown to hinder the white cell response in cancer, reduce haemoglobin quality (causing fatigue) and interfere with calcium metabolism (promoting arterial calcification and high blood pressure).
Adult symptoms of chronic lead poisoning include muscle pain, nausea, headache, depression, personality change, chronic fatigue, anxiety, diziness, neurological deficits, weakness, loss of appetite, loss of weight, constipation, decreased fertility in men, adrenal gland disease, memory loss, abdominal pain, dizziness, weakness and immune dysfunction. Other problems include anaemia, kidney failure, cardiovascular disease, hypertension, delayed development, problems with balance, cataracts and hypothyroidism.
Children usually present with hyperactivity, temper tantrums, fearfulness, fatigue, learning disabilities, speech disturbance, mental retardation, seizures or ataxia.
A study published in a 2003 edition of the New England Journal of Medicine showed that no amount of lead is safe and that blood lead levels were inversely related to children’s IQ scores. Even levels as low as 10 parts per billion which were previously thought to be safe were associated with reduced IQ levels. A study in the Archives of Internal Medicine in 2002 showed that all cause mortality is lowered by lowering blood lead. They stated that “morbidity and mortality is going to be lower, the lower you can keep your blood lead levels throughout your entire lifetime.” A study of over 2000 women aged 40-59 reported in the Journal of the American Medical Association in 2003 found that lead stored in women’s bones and released when they reach menopause significantly increases their risk of fatal high blood pressure. The NHANES study published in the November 2002 edition of the Archives of Internal Medicine showed that after adjusting for other confounding factors, individuals with elevated lead levels (blood lead levels of >20ug/ml) had a 46% increased all cause mortality, a 39% increased mortality from circulatory disorders and a 68% increased cancer mortality. The paper concludes by saying that “people with lower levels of lead live longer with less morbidity and mortality from ALL diseases.“
Lead is also a cause of kidney failure. A study published in the August 2006 edition of the American Journal of Medicine has found that even low levels of blood lead accelerate progressive renal failure in nondiabetic patients with chronic kidney disease. 188 patients with chronic kidney disease and low normal blood lead levels with no lead exposure history were observed for 24 months. 32 of them were then randomly assigned to either get chelation therapy or placebo. Renal function and glomerular filtration rate improved in the chelation group. The study concluded that environmental exposure to lead, even at low levels, may accelerate progressive renal failure of nondiabetic patients with chronic kidney disease.
A study published in the October 2006 online edition of the journal Circulation found that the risk of heart attack and stroke is elevated in people with blood levels of lead that were previously considered safe. Previously, blood levels greater than 10mcg/dl were considered dangerous. This study looked at 14000 adults who had blood levels of lead monitored for a 12 year period. During that period, 1661 participants died (267 from heart attacks, 141 from strokes and 411 from cancer). After adjusting for other risk factors, the researchers found that those with blood levels greater than 2mcg/dl (0.1mmol/l) were more likely to die of heart attack or stroke, but not cancer. Those with the highest blood level (3.6-10mcg/dl) had an 89% increased risk of heart attack and a 151% greater risk of stroke. The researchers were not sure if the lead levels reflected current or past exposure.
It has even been proven that lead is affecting the health of our brain when a study published in the December 2004 edition of the Journal of the American Medical Association found that individuals with elevated bone levels of lead had a nearly 300% greater risk of developing cataracts. The eye is a direct extension of the brain. The researchers concluded that “common accumulations of lead are an unrecognised risk factor for cataracts”.
Lead is having an adverse effect on our health, our energy, our longevity and the illnesses that we develop.
In our current environment, avoiding environmental toxins completely is impossible. Research has shown that during a hot 10 minute shower the body absorbs the same amount of chlorine, lead, cadmium and fluoride as would come from drinking 8 glasses of the same water. A recent study of 3800 US adults and children showed traces of 11 heavy metals, six pesticides and several other toxins. Additionally, because heavy metals are stored in bone and bone turnover occurs incredibly slowly there is a constant leaking of heavy metals out of storage which is why oral chelation should be done continuously. Bone turnover and therefore leakage of toxic heavy metals is increased at times of stress, particularly illness. Dr Garry Gordon, the world’s leading authority on chronic heavy metal toxicity states “the moment you stop chelating, the heavy level of lead in the dust, air, food and water will be greater than what you require in your bones and tissues. Therefore, you need to be excreting and removing more of the toxic metals than are coming into your body. Since longevity is increasing, it becomes extremely important to understand that chelation is necessary for those of us who want to be alive at 80 or 90, especially if we want to retain our mental faculties”. Research done in Sweden has shown a 90% decrease in the incidence of cancer in patients who have had had chelation therapy. For more information, see Chelation Therapy.
Lead and other toxic heavy metals particularly accumulate in the pituitary gland reducing excretion of growth hormone. Oral chelating agents protect the pituitary gland and therefore increase growth hormone levels. Lead also makes mercury 100 times more lethal. A study published in the journal Toxicology and Environmental Health in 1978 showed that rats given a dose of mercury sufficient to kill 1% of tested rats when combined with a dose of lead sufficient to kill 1% of rats, resulted in the death of 100%. This is why we should be focusing on reducing our body burden of all heavy metals.
Diagnosis of acute lead poisoning is made on a blood test. However this is not a good way to diagnose chronic lead poisoning because most of the lead is in the tissues and not in the blood. Confirming the diagnosis of elevated tissue levels may require several strategies because it is well recognised that blood levels of heavy metals are not representative of tissue levels and frequently fail to identify significantly toxic tissue levls i.e levels that are causing tissue damage. Blood tests are a measure of recent or ongoing exposure. 30 days after acute exposure there is little evidence of any remaining toxic metal in the serum as it has been deposited in other tissues. Random urine tests show only what is being detoxified by the kidneys so are a poor test because heavy metals are predominantly stored in tissues rather than excreted.
Many studies that have been done which have found no association between lead and disease have been done with blood tests for lead. Imagine a leaky bath tap dripping into a bath. The leaky tap represents the slow leak of lead and the bath the tissues of the body. Heavy metals like mercury and lead are not readily excreted by the body so now the bath has a plug in it. Eventually the bath is full. If the plumber is called and only looks at the tap, a major problem is not apparent. Only if the plumber checks the bath is the magnitude of the problem recognised. Looking for lead toxicity by just doing a blood test is like just looking at the tap. The problem worsens as we age and our bones start to thin releasing their lead. Now as well as the tap dripping into the full bath, the bath is shrinking and there’s a lot of overflowing water. Bone turns over every 15 years, so assuming no further lead exposure (which is impossible), some form of chelation process has to continue for 15 years to remove the lead.
*Anyone with a chronic illness should be assessed for heavy metals.
The joint Guidelines for Toxic Metals prepared by the American Board of Clinical Metal Toxicology, the American Association of Environmental Medicine and the International College of Integrative Medicine state that “ANY test showing heavy metals deserves to be treated, if only for preventative purposes. Ideal levels of heavy metals in human tissue are zero if we are to prevent the development of chronic illness. Arbitrary threshold values to define ‘toxic’ levels proposed by conventional occupational medicine are not useful and may be harmful if the patient is left untreated.”*