Australia is in the midst of a silent epidemic in people over 20 years old, but the epidemic involves children as well. Despite having a huge impact on the health of the people affected, including developmental and behavioural problems in children, it is largely ignored by the very health services that ought to be protecting its victims.

Outcomes of this epidemic are cardiovascular disease, neurological disease, renal disease, immunosuppression, and various types of cancer. In children it results in hearing and learning problems, and behavioural problems including violence.

The cause of the epidemic has a name; lead, atomic symbol Pb, plumbum.

Lead has been used by mankind for over 5000 years. It was easy to purify, had a low melting point and was easy to work. It was used for drinking vessels and pipes, lead salts were used as cosmetics, and lead was even added to wine by the Romans because it added a sweet taste. It was such a handy metal that it was used everywhere it was available.

It was identified as a toxin over 2400 years ago, and the disease it caused is  named plumbism. But lead was so useful it continued to be used regardless, and awareness of its toxicity waxed and waned.

Benjamin Franklin wrote a letter in 1786 describing the serious health effects of lead. He identified occupations that used lead including lead miners, printers and typesetters, roofers, glaziers, plumbers, artists stonemasons and soldiers.

It was recognized that if you worked with lead, you risked harm, but the general public was largely spared the ill effects of lead. That’s not quite true since lead glazed dishes, pewter vessels and crystal glass were used by rich folk, at the expense of their health.

This changed when lead paint started to be used to paint houses and public buildings. Lead paint, with up to 50% lead content, was durable, it protected against rot and fungus. It also tasted sweet and proved to be irresistible to children and animals.

There are many Australian accounts of children having serious neurological and renal damage, caused by licking or eating lead paint. The extreme danger posed by lead paint was eventually recognised and it was largely banned by the latter part of the 20^th century. But it remains a very real threat because of the lead dust produced when older (pre-1970) houses are renovated.

There was also a new source of lead in the environment. Between 1930 and 2000 over 10 million tonnes of lead were released into the atmosphere worldwide. The highest concentrations of lead from leaded petrol were to be found near major roads, but the very fine lead nanoparticles were spread on the wind as far as the North and South poles.

Wherever there were roads, leaded petrol ensured that ordinary people were exposed to the dangers of lead. Areas of heavy traffic, near main roads, in for example London, are permanently contaminated with lead. It is found in the ground, in attics, wherever dust can accumulate. If vegetables are grown in ground contaminated with lead, they will contain lead.

There are also areas of Australia where lead ore is naturally abundant and covers the ground.  In far north Queensland, cattle eat the dirt because it is sweet, and the lead-containing plants cattle eat mean they have raised lead levels in their flesh and bones.

The occupants of the traditional lead mining towns of Broken Hill and Mount Isa are exposed to additional lead hazards because lead in the ground is augmented by lead from the mining and smelting operations. Port Pirie is a smelter only , but smelter emissions and dust from handling the ore have created a significant lead hazard for Port Pirie residents. There is a trail of lead pollution along the railway tracks between Broken Hill and Port Pirie because of the transport of uncovered lead ore

It’s important to point out that cases of severe lead poisoning are uncommon, but they do happen. Pica, often caused by iron deficiency, causes children to eat dirt containing lead. Old car batteries and battery acid are a particular danger and lead paint trumps most other sources of lead in terms of the danger of lead exposure.

While severe lead poisoning is rare, a far more subtle effect happens at relatively low levels of circulating lead.

Lead has 3 primary effects in the body: (1) inhibition of calcium channel operation which in the brain interferes with neurotransmitter release, (2) binding and inhibition of sulphur-containing enzymes and proteins in the brain and elsewhere and (3) generating oxidative damage to cell membranes, cell structures and DNA. Some of the damage from these effects is reversible, some is not.

Wherever calcium resides in the body, so does lead. Lead accumulates in the body, particularly in the bones, taking the place of calcium. Lead in the bones remains for decades, except when calcium would normally be lost, such as during gestation, breastfeeding or osteoporosis and some blood cancers. Lead is also retained in the brain for many years.

Lead accumulates in the arteries, causing inflammation and leading to atherosclerosis as well as peripheral vascular disease. It can increase blood pressure, cause damage to the kidneys and other organs, and between oxidative damage, DNA damage and lead-induced immunosuppression, it can cause cancer.

Health authorities have set a maximum allowable blood lead level of 5ug/dl. If a laboratory detects a higher level of lead in the blood, it is treated as if lead were a notifiable disease and is noted by the health department. In children, a notifiable level of lead prompts the health department to advise the parents on reducing lead exposure, and in the case of very high levels, applying treatment to remove excess lead.

Even in the absence of continued lead exposure, lead in the bones will maintain a low and constant level of lead in the blood. How low?

Lead in the blood that is between 5-10 ug/dl has been shown to be linked with increased heart and arterial disease, high blood pressure and behavioural changes.

Large scale epidemiological studies have conclusively shown the link between blood lead levels and cardiovascular disease. Violent offenders, whether youths or adults, are more likely to have raised blood lead levels. Thanks to leaded petrol, we have had the opportunity to link a myriad of human diseases to lead exposure and blood lead levels. The link between lead levels, youth crime and violence and adult violence raises interesting sociological issues.

It is noteworthy that lead workers face a much higher exposure to lead than the general population, so either they are presumed to tolerate much higher levels of blood lead before they face any harm, or the effects of lead are considered oart of the profession. The actionable level of blood lead for a lead worker is currently between 20-30 ug/dl, 4-6 times higher than the general population. It is worth noting that aside from a reduction in the actionable blood lead level, the WHS procedures have been inchanged for over 40 years.

It would be nice to be able to say there is a cure for our lead epidemic. While that’s certainly possible it’s unlikely at this point in time. We are still exposed to lead paint; light aircraft still use leaded petrol and lead is found in auto paints, spices and even dark chocolate. But there are glimmerings of hope.

Lead can be removed from the body, even though it can be a long slow process to remove it from the bones. But enough lead could be removed to reverse at least some of the deleterious effects. The process of removing lead requires a chelation agent, a chemical that binds lead and excretes it from the body. You take a capsule or have an IV drip containing a chelation agent and that’s it.

Actually that’s only wishful thinking on my part. The American OHSA (occupational health and safety agency, document 57 FR 26627, May 4, 1993, as amended at 58 FR 34218, June 24, 1993; 63 FR 1152, Jan. 8, 1998; 71 FR 16674, April 3, 2006; 77 FR 17890, March 26, 2012; 84 FR 21598, May 14, 2019) states: Routine chelation to prevent increased or reduce current blood lead levels is unacceptable whatever the setting.

Any non-therapeutic chelation therapy, that is chelation in the absence of clival signs of lead poisoning is deemed to be prophylactic and therefore unacceptable. Removal from lead exposure is the only treatment allowed unless there are gross symptoms of lead poisoning.

Removal from lead exposure does NOT lead to removal of lead from the body. Lead gets stored primarily in the bones (95%) and loss of lead from the workers body is relatively minimal.

When chelation therapy was first being established, there were deaths due to stupidity and ignorance. While the therapy has evolved into something that is very safe, the medical profession has never forgotten that chelation therapy is dangerous. Institutions like the Harvard Medical School say so, and that’s what counts regardless of the considerable evidence that chelation therapy is now not only safe but of immense potential value. Medicine does not necessarily follow science or common sense.

I’ll close with some anecdotes about chelation.

Infants can be gravely affected by lead from the renovation of old houses. The symptoms that result from the lead exposure can mimic autism. Chelation therapy using oral chelators can cause profound improvements in lead affected children.

I proposed a solution to a large north Queensland lead miner to rectify their appalling workplace health and safety procedures when a workers blood lead levels exceed the actionable level. This included a simple way to measure bone lead levels, and a regime using chelation therapy to remove excess lead. Alas it appears that worker safety is less important than following the rules, even if they are totally wrong.

I mentioned the lead in cattle in North Queensland. The high lead levels meant they were deemed unfit for the live export trade to Indonesia. They now spend a few weeks in a feed lot eating a chelating agent which removes the lead, and then are fit for export.

We can get the lead out of cattle, but it’s too hard to do the same for people in our health system. What a woeful state of affairs.

Then again, lead still causes problems in the US as well: see Special Report: Thousands of U.S. areas afflicted with lead poisoning beyond Flint’s (yahoo.com)

Of course you have to test people to find out if they’re lead affected. At the end of the 20th century, only 1 in 2000 Australians were test for raised blood levels, and the testing rate is now even lower since the NHMRC recommended against widespread blood lead testing because it was a waste of money. Medicare actively discourages blood tests for lead unless lead poisoning is suspected.