By Dr. Mercola
Lead has a cumulative effect on multiple organ systems in your body and is particularly harmful to young children. After it enters the body, it is distributed through the brain, kidney, liver and bones, and is often stored in the bones and teeth.1 There is no known safe exposure to lead, which often affects young children and lower socioeconomic groups the hardest.
However, humans have a long and intimate relationship with lead, dating back to 3000 B.C. when the Roman Empire used it to create pipes for their plumbing and to sweeten wine that they then shipped all over Europe.2 Documents from that period report symptoms of colic, anemia and gout attributed to overexposure to lead.
Some historians even believe lead poisoning hastened the fall of the Roman Empire. The oldest known piece made of lead is a figurine from 4000 B.C., found in Egypt.3 In more recent years, the durability of the heavy metal made it an excellent additive to paint, and the chemical properties made it an attractive gasoline enhancer to curb knocking caused by the premature firing of gas in the cylinder.4
However, while manufacturers may have been enamored by the properties of the heavy metal, it has placed a heavy burden on human health and the environment. The dangers of lead have been documented since the second century B.C., but it has taken nearly 4,000 years to fully understand the consequences to human health.
While those consequences are significant, and may even represent one of the biggest health risks in human history, manufacturers removed it only after years of fighting and litigation, insisting the product is completely safe despite hundreds of research documents to the contrary. Today we have several heroes to thank for the significant drop in lead levels we enjoy. But, while several battles have been won, the war continues.
Lead and Calcium Thick as Thieves
Lead levels in the average American have dropped by more than 75 percent since the 1970s, but remnants of pollution from past decades continue to endanger your health. Lead can still be found in pipes, in the soil and in older paint. It is a problem that is possible, but expensive, to fix. To make things more difficult and dangerous, federal funding to remove lead has been slashed, and local governments don’t have the resources to pick up the slack.5
Lead and calcium are chemically very similar, making lead a competitor at the cellular level and disrupting many different bodily systems.6 In your neurological system, it may disrupt neurons that use calcium to transmit information.7 This is why lead has a particularly devastating effect on the developing neurological systems and brains of children.
The presence of lead will cause some neurons to fire more and decrease the signals in others. This may alter neurological development in the brains of children who have absorbed lead from their environment. In the past, researchers noted behavioral and cognitive changes in children who were brought to the physician for testing and treatment.8
Researchers found children, and those living in poverty, have a higher incidence of lead poisoning and have higher lead levels. Symptoms of chronic exposure or lead poisoning don’t usually appear until years later. Virginia Rauh, an environmental health scientist at Columbia University, explains that the neurological poisoning in children becomes more apparent as they mature and must use more fine-tuned skills.9
Epidemiological studies have revealed African-American children have a higher incidence of lead poisoning, potentially from a slightly different way of metabolizing the heavy metal. Research has demonstrated that people of African-American descent absorb calcium at higher rates,10 sometimes as much as 50 percent more efficiently.11 While this may be advantageous for calcium levels, it is a disadvantage when children are exposed to lead.
Research Scientist and Pediatrician Herbert Needleman Provided the Foundation
Dr. Herbert Needleman began his medical career in the 1950s and quickly began his crusade for better lead safety standards after treating a long parade of children with lead poisoning as a pediatrician at the Children’s Hospital of Philadelphia.12 After years of treating children and observing the long-term effects of exposure, he maintained that a slow buildup of lead in the system could trigger symptoms even in the absence of overt poisoning.
To test the hypothesis that long-term exposure at low levels may affect cognitive skills and behavior, Needleman required a method of testing lead levels. Blood tests only revealed the current exposure, but would not capture the amount of lead the children were exposed to over time. As he transitioned from treating pediatrician to research scientist, he turned to testing baby teeth that absorbed lead at the same rate as bone.13
Needleman found teeth would reveal long-term lead exposure and absorption, and found inner city African-American children had levels five times higher than their suburban counterparts.14 Next, he gathered data from nearly 2,500 children in Boston and demonstrated the higher the levels of lead the children absorbed, the greater their neurological deficits.
As lead-based paint and gasoline were the biggest contributors to lead poisoning in children, Needleman and public health expert and colleague Dr. Philip Landrigan began lobbying to remove lead from these products. However, fearful of monetary loss, the industry fought back. Using an army of paid experts to pick apart the research, the industry criticized the data collection and analysis, leading to a formal investigation of scientific misconduct by the University of Pittsburgh where Needleman was employed.15
The industry not only attacked the science, but also personally went after the scientist. Today, Needleman suffers from Alzheimer’s disease, but his son reports that the investigation led by the university only signaled to his father the university’s distrust of a scientist who had given decades of service to his employers. After years of fighting, the science and the scientist were exonerated.16
Geochemist Clair Patterson’s Persistence Pays Off
As Needleman was fighting the University of Pittsburgh, geochemist Clair Patterson, Ph.D., was fighting the oil companies to have lead removed from gasoline. Even when it was added to gas in the 1920s it was known to cause neurological damage. Still, the process was pursued as it enabled the oil companies to net greater profits. Ironically, the researcher from General Motors suffered lead poisoning, but continued to marvel at the profits the company would make.17
Patterson was a geochemist working to establish the age of the earth by measuring lead isotopes. He was confounded by results he thought may have been tainted.18 This led him to use core samples from ice layers in Greenland. He was able to identify ice that had been formed during the Roman Empire and Industrial Revolution, and then discovered the ice that formed since 1920 had a major spike in lead concentration.
In 1965, Patterson published the book, “Contaminated and Natural Lead Environments of Man,”19 in an attempt to bring the dangers of lead gasoline on health and environment to light. Again, the industry brought to bear its influence to discredit the science and the man in an effort to maintain inordinate profits at the cost of human health.
Although an acknowledged world expert in atmospheric lead contamination, Patterson was excluded from panels at the U.S. Public Health Service and the National Research Council as a result of pressure from the oil industry.
Despite the overwhelming odds of one man fighting the oil industry, Patterson was instrumental in bringing forth the 1975 U.S. mandated option of unleaded gas at the pumps. It took substantial persistence, but finally in 1986 Patterson’s persistence triggered the removal of lead from all gasoline in the U.S. As a result, blood lead levels dropped nearly 80 percent by the late 1990s. In my view, he is one of the greatest unrecognized public health heroes of the 20th century.
Decadeslong Lawsuit Illustrates Lead-Based Destruction
Gary Gambel, a New Orleans attorney, took up the fight in 1994 when he met young single mother, Casey Billieson. Gambel was part of a team of lawyers in the New Orleans Lafitte area doing soil testing for lead. On the advice of Gambel, Billieson had her two young sons tested and found they had been poisoned, and likely had been for years. In this short video, another mother tells a recent story of how a home renovation during her pregnancy affected her unborn son.
What began in 1994 did not conclude until 2016.20 Gambel’s interest in lead poisoning began when an associate uncovered several positive lead poisoning tests while working on another case. The original plan was to help several families pro bono to move into housing not contaminated by lead paint. However, all the families he had contact with had children who tested positive for lead, and the housing authority hadn’t done anything to rectify the situation.
The housing authority of New Orleans (HANO) was doing nothing to keep their units up to code where thousands of families and children were living. In 1985, the Centers for Disease Control and Prevention set a standard of 25 micrograms per deciliter (mcg/dL) for children to be treated. At that time children in the New Orleans area regularly tested higher, and those who lived in the projects administered by HANO tested highest of all.
Lead levels in the plaintiffs who worked with Gambel regularly tested between 20 mcg/dL and 40 mcg/dL. To put this in perspective, lead levels just over the current 5 mcg/dL triggered the investigation into the water contamination in Flint, Michigan.21 Unfortunately, many of the plaintiffs in the New Orleans case did not receive a settlement as they were either killed or have since been incarcerated.
Howard Mielke, Ph.D., a research professor in the department of pharmacology at Tulane University, and his colleague examined crime in six cities, including New Orleans, and how it related to lead emissions from gasoline.22 They found what the mothers of these children had long been claiming: Increases in lead were strongly associated with increases in crime. In other words, exposure to lead had permanently altered the ability of these children to even enjoy the stability of a job.
The Case Continued
After a private company was appointed to administer the project renovations and abatement in New Orleans, Gambel and his partner saw an opportunity to file a class action suit, representing all the families and children who lived in the HANO projects, claiming the children were exposed to lead from paint and the metal that settled in the soil from lead gasoline.23
Plaintiffs in the lawsuit were scattered across the U.S. after being forced to relocate when Hurricane Katrina flooded their neighborhoods in 2005. Unfortunately, Katrina not only forced relocation of families, but also destroyed medical records of children so that parents were unable to prove their children had lead levels high enough to qualify for the class action suit at the time of the settlement.
Some families had one child awarded compensation but not others, as those medical records were lost. Today, Gambel closely guards the documents gathered during their 22-year-long court case.
The court fight was long and protracted, requiring thousands of hours from the attorneys on both sides. Gambel’s work attracted the interest of another lawyer who had taken on big companies after large disasters had struck. This was fortuitous for Gambel, as he was a relatively new lawyer working in a small firm. Gambel commented:24
"When I filed that lawsuit, in hindsight I was just naïve. As a young lawyer and a startup firm, there were a lot of people asking me, ‘How are you going to do this?’”
Lead Continues to Threaten Children
Although health risks associated with lead are recognized and well publicized, it hasn’t removed the risk to children. Pediatricians in Oregon take a different approach to testing children for lead levels. Some use the Oregon Health Authority’s recommendations that direct parent questions about exposure when children appear asymptomatic, while other pediatricians take a more aggressive approach, doing blood tests on all 1- to 2-year-old children.25
A recent study indicates performing blood tests on all children may be warranted.26 The researchers found a significant gap in numbers between those estimated to have elevated blood lead levels (EBLL) and those reported to the health departments. The authors of the study wrote:
“While we find no evidence of under-ascertainment in a number of states, the majority appear to successfully identify fewer than half of their children with EBLL.”
Based on their data, the authors estimated there were 1.2 million children with EBLL in the U.S. between 1999 and 2010, which represents a number significantly higher than the number reported. They concluded that under-testing was “endemic” in many states.27 Although the problems with lead-polluted water in Flint, Michigan, raised awareness, many physicians continue to underestimate the number of their patients who may suffer from high lead levels.
To compound this issue, a recent statement was issued warning that all blood lead levels tested using tests by Meridian Bioscience Inc. may underestimate the amount of lead in the blood.28 The U.S. Food and Drug Administration learned about problems with the Meridian Bioscience tests after a number of complaints surfaced.
Although the problem with the test is unclear, pediatricians are being advised to retest all patients whose blood test returned with a level less than 10 mcg/dL. It is unclear how many people may need retesting, but it is known this test is used in nearly 50 percent of all blood lead level tests.
Strategies to Avoid Lead Poisoning
The issue of preventing lead poisoning is a pressing matter, whether you have young children in your home or not. Adults are certainly adversely affected by lead contamination, including neurological dysfunction. Harvard Medical School offers the following suggestions to protect yourself and your family against lead exposure:29
- Was your home built before 1978? If so, get it inspected to determine whether it has any lead paint
- Lead paint removal should be done by a certified professional to ensure safety. The dust is highly toxic. For more information on this, see the EPA’s “Lead-Based Paint Activities Professionals” page30
- Get your water tested for lead
- Be mindful of the fact that certain household objects may also contain lead. For information about lead-containing products and recalls, see the Consumer Products Safety Commission’s website31
- Get your child tested for lead. Ideally, all children should be tested at ages 1 and 2, and again at ages 3 and 4 if you live in an older home. It’s also recommended to test your child’s level whenever there’s concern about exposure. A level of 5 mcg/dL or higher is considered dangerous