How can we reduce the world’s crime rate, particularly the rate of violent crime? When the crime rate rises or a horrific crime takes place, people are quick to find blame in everything from violent movies to video games. Some believe crime can be reduced only with more prisons, more police, higher fences, more cameras and more guns. Others believe crime can be reduced with better education, fairer income distribution, lower unemployment, fewer drugs and fewer guns. But there is increasing evidence that the real culprit is the world’s oldest known environmental poison – lead.New York Mayor Rudy Giuliani was quick to take credit for reducing the city’s homicide rate by 67% between 1994 and 2001. He began with a tough guy approach, sweeping up petty crimes and vandalism in what is known as a “broken window” strategy.
But then someone noticed that NYC crime was on a downward trend before Giuliani took office. It was already down 12% from its peak in 1990. So what was really going on?
In the year 2000 a lead paint removal consultant named Rick Neven published a paper which showed a correlation between lead levels and crime rate. The correlation was clearest when a 23 year time-lag was added. Leaded babies seemed more likely to grow up and become criminals.
It was a frightening correlation, but lead and other toxic metals continued to spew from coal power plants and many countries including some in the Middle East continued to use lead as an anti-knock component in gasoline. After all, correlation doesn’t necessarily mean causation. So if you’re pondering whether leaded wine jars and leaded plumbing caused the fall of Roman civilization, you might argue in Latin: Post hoc ergo propter hoc. This is a well-known logical fallacy which could be used to prove for example that: I wore my lucky socks today and the sun didn’t fall out of the sky, therefore my socks hold up the sun!
But sometimes evidence piles up and a coincidental correlation becomes increasingly unlikely. Correlations between drugs and crime or economics and crime didn’t hold up across the decades but correlations between lead and crime held across many decades, many cities, ethnic groups and even across diverse nations. As Sherlock Holmes would put it, when you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth. So whodunit? The culprit is lead (chemical symbol Pb).
We should have known all along. In his writings De Architectura, first century BC Roman architect Marcus Vitruvius Pollio wrote:
“…lead is found to be harmful for the reason that white lead is derived from it, and this is said to be hurtful to the human system. Hence, if what is produced from it is harmful, no doubt the thing itself is not wholesome. This we can exemplify from plumbers, since in them the natural colour of the body is replaced by a deep pallor. For when lead is smelted in casting, the fumes from it settle upon their members, and day after day burn out and take away all the virtues of the blood from their limbs. Hence, water ought by no means to be conducted in lead pipes, if we want to have it wholesome.”
Beyond lead’s suspicious presence during the fall of Roman civilization, it rendered Augustus Caesar infertile. It also deafened Ludwig Von Beethoven and ultimately killed him. Queen Elizabeth I, artist Francisco Goya and US President Andrew Jackson were all afflicted with lead poisoning (plumbism) and one of the oldest known environmental problems is still with us in the twenty first century.
A 2012 study of Saudi Arabian children published in the International Journal of General Medicine found correlations between blood lead levels and: the use of certain cosmetics (e.g. kohl), the use of toothpaste, handling of newspapers when preparing food, use of canned food, chewing on colored toys.
Other studies found high lead levels in Saudi Arabian street dust especially near heavy automobile traffic. In the year 2000, thirteen members of a Palestinian family had symptoms of lead poisoning after using flour which had been contaminated with lead from a millstone.
Lead can cause deafness, infertility, stomach ailments, irritability, headaches, confusion, seizures, anemia and other maladies. Lead also lowers intelligence and specifically damages parts of the brain responsible for emotional control, attention and verbal reasoning. You might even say that it attacks our conscience.
Now for the Good News on Lead
For most of the world’s population, this story is well on its way to a happy ending. The United States was the first to ban leaded gasoline back in 1972 and then a leaded paint ban in 1978. Comprehensive lead testing of products, homes and food is now required. Blood lead levels dropped rapidly, as did crime.
Jordan finally banned leaded gasoline after 2001. In 2011 the United Nations Environment Programme (UNEP), working with the Natural Resources Defense Council (NRDC) announced that:
“Lead has been removed from gasoline in more than 175 countries worldwide – representing near-global eradication. A new, independent scientific analysis shows the result of this achievement is a 90 percent drop in blood lead levels worldwide, as well as 1.2 million lives saved each year and $2.4 trillion generated in health, social and economic benefits annually.”
But several nations including Afghanistan, Iraq, North Korea, Myanmar and Yemen are still using leaded gasoline and many others have lead contaminated plumbing, soil, paint and household products. It has taken more than 2000 years to solve the world’s oldest known environmental problem and we’re not yet finished.
Image of antique leaded gasoline pump by Martin Bangemann via shutterstock.
Image of Egyptian woman wearing kohl makeup by Tamara Kulikova via shutterstock.