Lead has no known function in the human body. It’s an insidious toxin with a very broad range of symptoms, and even people who appear healthy can have dangerous levels of it in their blood. The problem of lead contamination is entirely a result of civilization, since levels in pre-industrial people (in the range of 0.01 micrograms/deciliter (mcg/dl)) were around 100 to 1,000 times lower than blood levels typically found in people today. (Lead Toxicity, A Review of the Literature. Part I: Exposure, Evaluation, and Treatment Lyn Patrick, ND)
One of the major players in this disaster was the Ethyl Corporation. In its pursuit of profits it criminally exposed workers to lead in its factories, and lied about it while they were dying. Its lead-based-no-nock-gasoline-additive eventually put about seven million tons of lead out through the tailpipes of cars into the atmosphere. (1) (The Ethyl-Poisoned Earth by Alan Bellows)
The main cause of lead’s toxicity is its ability to interfere with many enzymes by binding to their sulfhydryl groups. Short term measurable effects of lead poisoning begin at 25 mcg/dl. Obvious symptoms begin to occur at levels above 40mcg/dl in adults, and above 60 mcg/dl in children.
The list of potential health problems related to lead is a very long one: Lead can damage hearing, vision, muscle coordination, the blood, kidneys, heart, and reproductive system. Symptoms can include abdominal pain, anemia, loss of appetite, constipation, delayed growth, depression, diarrhea, fatigue, headaches, irritability, decreased libido, memory loss, muscle pain, nausea, personality changes, problems with sleep, an unusual taste in the mouth, weakness, tingling in the extremities, vomiting, and weight loss. In one recent study those people with blood lead levels in the top 20% (over 2.11 mcg/dl) of the subjects had 2.3 times the odds of suffering from a major depressive disorder, and almost 5 times to odds of having a panic disorder as those in the lowest 20% (under 0.7 mcg/dl). (The average blood lead level of the group was 1.61 mcg/dl.) (Young Adults’ Blood Lead Levels Linked to Depression, Panic Disorder)
Exposure to even low levels might cause irreversible learning difficulties and mental retardation in children. One study found that the IQ scores of children dropped about 7 points across the sample as children’s blood lead levels varied from 1 mcg/dl to 10 mcg/dl. (2) (Very Low Lead Levels Linked With IQ Deficits)
The current consensus is that there is no safe level of lead exposure. Lead accumulates in the blood, soft tissues and bone; and its half-life is weeks in blood, months in soft tissues, and years in bone.
In the past lead was used commonly in house paint, as an additive to gasoline, and as a pesticide. One piece of good news in all this is that the Clean Air Act has helped reduce air emissions of lead nearly 90 percent during the last 20 years.
If you have a problem with lead contamination there are a number of things you can do to deal with it:
Make sure your child’s blood is tested for lead before age 2, and regularly to age 6, if there is the possibility of lead in the child’s environment. The major treatments are removal of the source of lead and possibly chelation therapy (administration of agents that bind lead so it can be excreted). (Chelation therapy – Wikipedia)
Around the home anything that has paint or a finish made before 1978 in the U.S. could be a source of lead. (It was banned in France and many other countries before 1920.) So you shouldn’t use cribs, bassinets, highchairs, painted toys, or toy chests made before that date. Lead paint is still sometimes found in toys and toy jewelry made today, so you should keep up on toy recalls by checking the lead recall lists. (Toy Hazard Recalls – CPSC) Unfortunately, 75% of the nation’s housing has lead paint. Broken down by time period, 90% of pre-1940 buildings have it, 80% of pre-1960 ones have it, and 62% of pre-1978 buildings have it.
Keep children away from paint chips (which they might eat) by closing and locking doors. You should create barriers between living and play areas, and the sources of lead. Apply temporary barriers such as contact paper or duct tape to cover lead sources.
Lead contaminated dust can be created by the friction of opening windows and doors, it might be blown in - coming from distant contaminated soils, or it can be generated during home renovation on a pre-1978 house. Lead dust is invisible and will pass through most masks and filters, so, if you have to sand or strip old paint that may contain lead, be sure to use a high quality mask to prevent inhalation of lead particles. Regularly wash children’s hands, pacifiers, toys, and any other items that might go in the mouth. Feed children nutritious low-fat meals high in calcium and iron, since this will reduce the amount of lead absorbed into the body. Wet-mop and wipe floors, window components, and other horizontal surfaces (counters, tables or floors) frequently. If possible, windows should be kept shut to prevent abrasion of painted surfaces, or only opened from the top sash. Don’t vacuum with a regular vacuum because it just lets lead dust fly around, but instead use a vacuum cleaner that utilizes a HEPA (High-Efficiency Particulate Air) filter. Pregnant women and children shouldn’t be present during a pre-1978 house renovation.
Lead was often in exterior oil-based paint prior to 1950, and as it ages it often contaminates soil about a house where children play. Stop children from playing in bare soil and close to the sides of the house. Instead, provide them with a sandbox more than 3 feet away from it. (If your do have a sandbox, parents should cover the box when it’s not in use to prevent cats from using it as a litter box.) Plant grass on areas of bare soil, or cover the soil with mulch or wood chips. Take off your shoes when you go inside, and, if you walk barefoot outside, wash your feet when you go indoors. Also, give your pet’s feet, legs, and undersides a rubdown with a towel after taking them outdoors.
Lead solder can contaminate house pipes, so, unless you know your pipes are uncontaminated, you should only use cold water from the tap for drinking or cooking. Also, if water sits in a pipe for several hours flush it from the tap for two minutes before drinking. You can also use a water filter to reduce the lead in the water you cook and drink with. For example, a simple Brita water filter will remove around 9o% of the lead found in tap water.
Replace inexpensive, horizontal, plastic blinds that have been made in Asia or Mexico, since these types of blinds often contain lead. Pregnant women and children should not be exposed to burning candles that could contain lead in their wicks. Don’t drink out of crystal glass. Soft vinyl lunch boxes can have dangerous levels of lead. Avoid using any personal care products that contain significant amounts of lead.
Hobbies that often involve working with lead are making stained glass windows, working with pewter and other collectible figurines, the glazing and firing of pottery and ceramics, making lead weights, reloading and making ammunition, making lead shot, target practice, making lead fishing weights or lures, refinishing furniture, and remolding. You should never sand, burn, or scrape paint unless you either know it doesn’t contain lead, or take the proper precautions. You should shower and change clothes after finishing a task that involves working with lead-based products.
Sites where lead might be a problem are hazardous waste sites, an area where cars are abandoned or repaired, ballast on a ship, a heavily traveled major highway or roadway, and an older house with peeling exterior paint. Also artificial turf playing fields have recently been found to produce a potentially hazardous amount of lead dust.
Other sources of lead are kohl (a South Asian cosmetic), sindoor (a cosmetic used by traditional Hindu and Sikh married women), herbal remedies (Ayurvedic preparations (Ghasard, Bala Goli, and Kandu), surma, and those of Chinese origin), and folk remedies (azarcon (also called Maria Luisa, Liga, Alarzon, Alkohl, Greta, Coral and Rueda), farouk, bint al zahab, and pay-loo-ah). Additional sources are solder which was used in the past to seal cans of food, ceramic glazes, lead curtain weights, lead bullets from hunted animals, bullets lodged in a person’s joints (since they deteriorate over time), imported candies that contain tamarind or chili, contaminated pottery, containers, cookware, or tableware. Older Christmas tree ornaments might be decorated with lead paint, and lead is in some tree light wires. Old newspapers, paper bags, magazines, and comic books could have been made with lead based inks. You should never burn treated lumber, since there will be heavy metals in the smoke. Industrial facilities, urban runoff, and atmospheric deposition are all sources of lead in the aquatic environment. Even your keys can often contain small amounts of lead.
Types of work that is typically associated with the risk of lead contamination include house construction and repair, shipbuilding, painting (especially marine related painting), iron processing, brass or copper foundry valve and pipe fitting, bronze work, welding, resurfacing, bridge, tunnel, and elevated highway construction; the demolition of bridges, towers, and other steel structures; lead battery manufacturing and recycling, radiator manufacturing and repair, scrap metal recycling, the electronics industry, the manufacture of some plastics, automotive repair, fishing weight production, leaded glass manufacturing, lead ore production, milling, and smelting; and municipal solid waste incinerators.
If your workplace poses a risk of lead contamination there are a number of safety precautions you should take: You should work with your employer to reduce lead and lead exposure in the workplace, perhaps by providing special ventilation equipment and/or fitted respirators. Wash your hands and face before eating, drinking, or smoking. Eat, drink, and smoke only in areas free of lead dust and fumes. Wet clean and HEPA vacuum lead-contaminated dust. Use separate work clothes and shoes while at work, and keep your street clothes in a clean place. Shower at work before going home, and launder your work clothes at work. If you take your work clothes home, wash and dry them separately.
For more information there are a number of sources you can contact. Here are some numbers:
EPA’s Safe Drinking Water Hotline 1-800-426-4791.
National Lead Information Center 1-800-LEAD-FYI, or 1-800-424-LEAD (5323).
Lead Surveillance and Reporting, Office of Epidemiology, 1-360-236-4252.
For information about lead in the workplace call the Department of Labor and Industries, 1-360-902-5663.
For a list of qualified testing laboratories for analysis of lead in paint, soil, or dust call 1-800-424-LEAD. Please specify that you are requesting the NLLAP/ELPAT list of laboratories.
HUD’s Lead Reduction Office, see: http://www.hud.gov/lea/leahome
For a home test, see: http://leadtestkit.com/kits1.html
You can also talk to your state or local health department about testing paint and dust from your home for lead.
To permanently remove lead hazards, you have to hire a lead “abatement” contractor. Call your local paint stores to find out if the contractor you’re considering has a good history with the store. Find a contractor who has been in business for several years, and can offer references. The longer they’ve been in business, the more they will likely know about lead. Find a contractor with whom you feel comfortable, and who can answer your questions and explain their work.
(1) Only one of the many consequences of this might have been a nationwide crime wave. A number of recent studies have shown a strong correlation between atmospheric lead levels and crime rates. The sharp decline in US crime rates, which began in the early 1990s, correlates perfectly with the reduction of leaded gasoline in the early 1970s. Other countries have seen similar declines, also delayed by twenty years. (The Ethyl-Poisoned Earth by Alan Bellows)
(2) Throughout this entire discussion there exists the common problem of inferring causation from correlation. Since direct experiments with humans would be unethical, many results require an assumption that lead is actually the cause of a health problem. At higher levels of contamination this assumption is unproblematic, but at lower levels this can be a source of uncertainty. Looking at the national lead standards for blood toxicity through the years, in the space of about 50 years, they have changed six-fold from 60 mcg/dl to 10mcg/dl. One reason to be skeptical of a 7 point IQ drop because of such low lead levels is that this suggests that people who grew up in the 1950’s and 1960’s would have had greatly reduced IQ’s, and this doesn’t seem to have been the case.
In 1960, 60 mcg/dl
In 1970, 40 mcg/dl
In 1975, 35 mcg/dl
In 1985, 25 mcg/dl
In 1991, 10 mcg/dl
It is certainly possible that raising a child’s blood lead level from 1 mcg/dl to 10 mcg/dl directly causes an average 7 point drop in IQ. The problem here is that there are potentially hundreds of confounding variables that could be creating the observed correlation. It’s possible that children with lower IQ’s have a greater tendency to chew on paint chips, be less well-nourished, or attend poorer schools. Also, parents with lower IQ’s might have a greater likelihood of living in lower quality housing and in more contaminated neighborhoods, be less aware of the dangers of lead poisoning, or be less competent when taking precautions, etc. So, the connection between lead at low levels and IQ could be one of children inheriting genes from relatively lower IQ parents, which predispose them to also have lower IQ’s.
In short, while it is entirely reasonable to take no unnecessary chances with lead poisoning (personally I would prefer my blood level to be literally zero), it’s only careful to remember that researchers haven’t actually established an airtight connection between the low blood lead levels and the observed health effects they are currently concerned about. (From: Toxic Lead Levels by Valerie)
(Lead – CDC) (Lead – Prevention Tips – CDC) (Lead – Sources of Lead – CDC) (Lead Poisoning Fact Sheet) (The Basics about Lead Paint – Home Safe Environment) (Lead Poisoning – Wikipedia) (How to Lower The Risk of Your Child Getting Lead Poisoning – eHow) (Simple ways to help prevent childhood lead poisoning - iVillage) (Helping Parents Prevent Lead Poisoning. ERIC Digest. by Binns, Helen J. – Ricks, Omar Benton) (Lead Poisoning: Prevention – MayoClinic) (Ways To Prevent Lead Poisoning by Dr. Ben Kim) (How to Prevent Lead Poisoning) (Prevention of Lead Poisoning – Cure Research) (Campaign for Lead Safety Awareness – Angie’s List) (Lead Poisoning Prevention – KeepKidsHealthy)
Tags: Causation Versus Correlation, Chelation, Clean Air Act, Crime, Ethyl Corporation, IQ, Lead, Lead Poisoning, Mental Health, Pregnancy, Toxins