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Get The Lead Out!: Ignore it and it won’t go away

Posted on November 4th, 2010 by Stephen Hardy | Print

Metals built our world.  Historians define the level of sophistication of a human civilization by its use and mastery over metals.  Starting with the Stone Age, we moved through the Copper Age, the Bronze Age and the Iron Age.

In our modern society, the use of metals goes way beyond the purely structural to build a car, bridge or skyscraper for example.  Metals play a vital role in almost every part of our daily lives.  But metals aren’t always our friends.  Even though they have been widely used for centuries, arsenic, mercury and lead for example are three very toxic metals.  We therefore have to balance the special properties of the metals, which makes them so attractive for industry, with their toxicity and capacity for harm.  But realizing they are toxic and knowing where the danger lies can sometimes take a very long time to figure out.  Let’s look at lead as an example.

Over the centuries, lead has been used in everything:  Lead in paint, lead in pewter, lead in crystal, lead in pottery glazes, lead in cosmetics, lead in jewelry, lead in weights and sinkers, lead in musket balls and later bullets, lead in solder, lead in plumbing, lead in children’s toys and crayons, lead on roofs, lead in batteries, lead in gasoline, lead in electrical appliances.  The list goes on.  But while it made our lives easier, lead has a dark side:  It is an insidious and potent poison.

We have known about the effects of acute lead poisoning for a long time.  Acute poisoning occurs when someone is exposed to a large quantity of lead over a relatively short period.  Acute lead poisoning can lead to seizures, coma and death.  We’ll come back to that.  What is more of a worry are the chronic effects caused by prolonged exposure to low-levels of lead.  You cannot see, smell or taste lead, so your body has no way of telling you the amount of lead in your system is too high.  And the higher the level of lead in your blood and the longer it stays there, the more damage it is likely to cause.

Lead is a metal with no known biological benefits.  It is also a metal that can damage almost every system in the body.  Lead also remains in the body for decades, principally in the bones.  While adults are also susceptible to lead, the biggest concern is its effect on children and the unborn.  Pregnant and nursing mothers can pass lead to the fetus and infant.  Children exposed to even small levels of lead risk brain damage, learning difficulties, behavioural problems, hyperactivity, antisocial behavior, permanent nerve damage and impaired mental development.

Governments around the world have long known that lead can contaminate the environment.  They have also known that lead is a public health risk capable of doing harm.

If governments have long known that lead exposure was harmful, why did they allow so much of it to be used so widely and for so long?  Why did they allow it to go into things like children’s toys, the paint in our homes and in gasoline, perhaps the biggest source of exposure?  And why in the light of overwhelming evidence, did they take so long to do something about it?  Was this just shutting the stable door after the horse had bolted?

Hundreds of scientific publications show potentially poisonous chemicals like lead can be taken up into our bodies and do us harm.  The principal of government environmental health policy for decades has been that most people are exposed to amounts too small or too infrequently to cause harm.  The problem comes when the small levels of exposure previously considered safe are later shown to be harmful.  There are numerous examples where chemicals previously considered safe have later been shown to do considerable harm and have been banned:  PCB, DDT, Thalidomide and Asbestos to name a few.  Lead is also going the same way. More and more data is accumulating that the lead blood level previously thought to be “safe” (10 micrograms/deciliter) is too high and should be halved (1).

This is a significant finding as according to figures from the World Health Organization, in some places over 90 % of children in both industrialized cities and rural areas have a blood lead level above the 10 micrograms/deciliter “safe” limit! (2).  If these new findings are correct, then their health is already being affected.  Fortunately, blood lead levels in children are generally falling worldwide, largely due to the removal of lead from gasoline.

In 1919 the Irish playwright and Nobel Laureate George Bernard Shaw (1856 – 1950) wrote:

All great truths begin as blasphemies

This is a very good if unfortunate description of the way we learn the truth about the safety or otherwise of a chemical.  Sadly, we have a long track record for getting things wrong.  There are already over 85,000 synthetic chemicals registered in the USA with another 2,000 being added annually.  Complete toxicological data is available for only 7 % of these (3) while over 40 % have no data at all! (4).  Given that any of these chemicals can make their way into the environment, it is worth giving a brief, if oversimplified view of how a new chemical is assessed as safe and what happens when things start to go wrong.

1.  Chemical is pronounced “safe”
As required by the government regulations of the day, the chemical manufacturer provides data that is used to pronounce a new chemical as “safe”.  The new chemical is often enthusiastically endorsed and used by the government of the day.  The government may even mandate the use of the chemical in legislation and prosecute and penalise those who do not use it.

2.  Vague concerns over use
After the chemical has entered widespread use, concerns begin to be raised about its potential safety.  The government or regulatory authorities often see those who raise the concerns as scaremongers, alarmists, quacks and eccentrics.  This is often accompanied by institutionalised ridicule and persecution of those raising the concerns and repeated assurances to the public that there is no cause for alarm.

3.  Warnings and restrictions on use
As the weight of evidence increases, the government or regulatory authorities finally begin to raise often vague concerns about the potential safety or use of the chemical.  These concerns may come years after the initial warning signs.  Rarely are the scaremongers, alarmists, quacks and eccentrics who first raised the alarm given any credit for making us aware of the problem.  The government may also restrict or put conditions on the use of the chemical through legislation and prosecute anyone who does not comply with the new legislation.

4.  Outright ban
The use of the chemical is eventually banned with stiff legislative penalties applying to anyone who continues to use it.  Finally, the government of the day supports litigation against the chemical manufacturer and recommends or enforces the payment of compensation to those affected by it.

Unfortunately, this about face can take decades or even generations, by then the damage has been done, the chemical is out in the environment, and many lives have been lost or ruined.

Disastrous environmental contaminations have been in the news a lot lately.  First, there was the 3-month Deepwater Horizon oil spill that spewed nearly 5 million barrels of oil into the Gulf of Mexico.  Then hundreds of children died from acute lead exposure in Nigeria because of poor gold mining practices.  Finally, there was the 1.1 million cubic meter (38.8 million cubic feet) toxic mud spill in Hungary on 4th October 2010.  The spill in Hungary is particularly noteworthy, where a burst reservoir at an aluminium factory in Ajka near Budapest released a flood of toxic metal residue that inundated towns and farmland and threatened to contaminate the River Danube, one of the major waterways of Europe.  All these catastrophes will have health and environmental effects that will last generations.

Whether environmental contamination is as sudden and dramatic as the above examples or small, unseen or unnoticed, the result is the same:  Something potentially harmful ends up in the environment that should not be there.

We live on a small planet.  So when lead or any other pollutant is released into the environment, it can eventually find its way into our bodies even if we live a long way from where the contamination occurred.  We are exposed to these pollutants through the air we breathe, the food we eat and the water we drink.  And unlike many of the other poisonous substances that are released into the environment daily and eventually broken down by natural processes, lead and the other poisonous metals are fundamental elements and cannot be broken down further.  They therefore remain in the environment in some form and continue to do harm for a very long time.

Ongoing environmental monitoring is therefore essential to assess any potential health risks.  For lead, mining and smelting are well known to contribute to the environmental exposure in residents of Port Pirie and Mount Isa in Australia for example.

Several inescapable things come from this discussion.

1. What is considered safe today may be harmful tomorrow.
2. We don’t know what we don’t know.  Unless you know what questions to ask or where to look to find out if something is safe, you won’t get the right answers.
3. Regular monitoring is the only way to know what is happening to the environment.
4. Governments don’t know everything.
5. Once released, pollution can stay in the environment for years and continue to do damage.
6. Governments often act far too late; doing the legislative equivalent of closing the stable door after the horse has bolted.
7. When we get it wrong, people die and lives are ruined.

So if we cannot rely on governments to know everything and protect us then we need to look after ourselves by becoming intelligent consumers.

There are currently two Promoting Good Health publications for those who want to know more about the contamination of our food and water and the potential consequences for your health.  The first is the eBook re-issue of the 2005 Australian Edition of “The Silent Threat”.  The second is the DVD presentation:  “Do You Want Chemicals With That?”.  Both are available through our website.  They will not be the last.

Until next time, stay happy and healthy.

(1) Chandramouli K et al (2009) “Effects of early childhood lead exposure on academic performance and behaviour of school age children“.  Archives of Disease in Childhood94, 844-848.
Abstract available online at:  http://www.ncbi.nlm.nih.gov/pubmed/19770197
(2) Tong S
et al (2000) “Environmental lead exposure: a public health problem of global dimensionsBulletin of the World Health Organization78: 1068-1077.
Available online at: http://www.who.int/bulletin/archives/78(9)1068.pdf
(3)  Gray J (2010) “State of the Evidence:  The Connection between breast cancer and the environment” 6th Edition.  Breast Cancer Fund.
Available online at: http://www.breastcancerfund.org/assets/pdfs/publications/state-of-the-evidence-2010.pdf
(4)  Bennett M and Davis B J (2002) “The identification of mammary carcinogens in rodent bioassays”. Environ Mol Mutagenesis39: 150-157.
Available online at: http://onlinelibrary.wiley.com/doi/10.1002/em.10068/pdf

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