What is Lead?

Lead is a naturally occurring element that is highly toxic to living systems. This bluish-gray substance is found in small quantities in the Earth’s crust, although traces of lead can now be found in all parts of our environment, both domesticated and wild. Most of this trace contamination is a result of human activity like mining, manufacturing, and the burning of fossil fuels. Once introduced somewhere, lead can remain dangerous for a very long time. For example, a home contaminated with lead dust from a renovation may lead-poison a child many years later. 

Lead has no particular taste or smell, but it does have a range of adverse impacts on human health, particularly in young children. Lead poisoning is in fact an environmental and public health hazard of global proportions. 

Common Sources of Exposure 

There are many ways to be exposed to lead and to ingest it. The most common way for adults to accumulate toxic levels of lead is through breathing workplace air and dust when employed in such industries as lead smelting, oil refining, and certain types of manufacturing. For preschool-age children, deteriorating lead paint is the most widespread and dangerous high-dose source of exposure. Barely measurable levels of lead have been shown to affect body systems. For example, one chip of old paint the size of a fingernail eaten by a child can create dangerously high lead levels in the body.

Another common pathway of exposure for kids is the dirt they play in outdoors, or even the dust inside a building. Most of the lead in soil comes from the settling of airborne particles released into the atmosphere from automobile exhaust, industry (fossil fuel burning and production byproducts), and the burning of waste. Such particles remain in the air about 10 days but stay in the soil for years. High levels of lead in soil today can often be attributed to old gasoline spills or the accumulated effects of past auto emissions. While this was a major lead exposure source prior to 1976, the use of lead in gasoline has since declined by 99.8% in the U.S. (but not in all other countries). Because lead in household dust and yard dirt is so common, it is important to wash surfaces and children’s hands often.

Lead can leach into drinking water from certain types of plumbing materials, notably lead pipes, copper pipes with lead solder, and brass faucets. Food can be laced with toxic lead if it was grown in contaminated soil or covered with airborne lead dust. Certain hobbies use lead, such as ceramics and leaded-glass design, and traces can be deposited on clothes, hands, tools, shop surfaces, etc. Fumes can also be breathed. Tobacco smoke is a source of lead in the air if lead was an ingredient in the soil amendments used to grow the tobacco. Lead, of course, is the main component of ammunition, so sportspeople who handle and use guns frequently should also be aware of the exposure risk. Metal roofing and devices used to shield from X-rays contain lead. Batteries of all types are a concentrated source of lead, and this is why they should be disposed of properly and not simply tossed in the landfill. 

Because of serious health concerns, lead in gas, paint, ceramic products, caulking, and pipe solder has been dramatically reduced in recent years. Even pencils no longer contain lead, but use graphite instead. Yet a surprising number of common items still contain lead and can pose a risk of toxic exposure, especially for the very young. 

Effects on Human Health

To be adversely affected by lead, one can have a single high-level exposure or the cumulative effects of repeated low-level exposures. Although anyone can be poisoned by this substance, lead is one of the greatest environmental health risks facing children today. Children under four years (including fetuses) are most at risk because the brain, nervous system, and tissues are still developing and are more easily damaged. Young children actually absorb 50% of the lead they take in compared with 10% for adults; also, toddlers have more hand-to-mouth activity and therefore ingest more lead-contaminated dust. 

Excessive exposure in children can cause brain damage, kidney damage, hearing impairment, vomiting, headaches, and appetite loss. It can retard a child’s growth and result in learning and behavioral problems. Unborn children are exposed through the mother because there is no barrier to lead in the placenta. This type of lead exposure can result in premature birth, smaller babies, decreased mental ability in the child, and prominent learning disorders. In adults, lead can increase blood pressure and cause digestive problems, kidney damage, nerve disorders, sleep problems, weak immunity, muscle and joint pain, and mood changes. Lead may decrease reaction time, cause weakness in fingers, wrists, and ankles, and possibly affect memory; it may also cause anemia (a blood disorder) and damage the male reproductive system. In fact, lead can affect almost every organ and system in the human body, with the most sensitive being the central nervous system. 

Unfortunately, most of the above effects are difficult to recognize until the damage is done. A person could have elevated blood levels of lead and not know it because even though long-term damage is occurring, people usually don’t show symptoms until levels are very high. Extremely high levels of lead exposure can result in miscarriage, birth defects, coma, and death. 

Signs and Symptoms

How you are exposed

• Determine if your home has lead paint and take steps to remove it properly. Keep children away from areas where paint is peeling and chipping.
• Since lead can come from solder or plumbing fixtures in the home or workplace, water from each faucet should be tested. Call the EPA Safe Drinking Water Hotline (800-426-4791) for info on labs certified to test for lead.
• Keep areas where children like to play as clean and dust-free as possible. “Leaded” dust is a common pathway for lead to enter our bodies. Especially if you live in an old home (pre-1970) or one that has been renovated, or if it’s situated on a busy street or near a lead industry, lead-aware housekeeping is key. Wet wiping and mopping with soapy water are much more effective at removing lead dust than sweeping with a broom and dry dusting. 
• High-phosphate detergents (tri-sodium phosphate or lead-specific cleaning products) are recommended for this purpose because they are extremely efficient at taking up lead particles. Change mop water often.
• After vacuuming, dust stays suspended for some time, so allow at least an hour (or even better, overnight) before wet-wiping. Try to vacuum when young children are not present, and limit vacuuming to once a week because of dust disturbance. Hard floor surfaces are much easier to clean than rugs and carpeting. Once contaminated, carpets, curtains, and other soft furnishings are very difficult to clean.
• Taking off shoes at the door prevents dust from being tracked into the home.
• Wash toys, stuffed animals, and bedding regularly. If a child’s bottle or pacifier falls on the floor, wash it before giving it back. 
• Regular hand washing, especially before meals, naptime, or bedtime, can make a huge difference in a child’s intake of lead dust. Wash hands with soap after playing outside, touching pets, and always before eating. Putting fingers, toys, and clothes in the mouth can lead to ingestion of harmful amounts of lead if children play in the dirt or in dusty areas. Try to provide grassy and clean play areas.
• Adults’ work clothes should be washed separately from family clothes if contamination is suspected. Do not shake or leave dusty clothes near children. Lead risk exists for workers in professions such as painting, auto body repair, motor mechanics, building, mining, and furniture restoration, to name a few. Hunters and hobbyists could also be exposed to lead. Keep children away from workshops and garages, and clean these areas thoroughly. 
• Infants, children, and pregnant women should not be in a home while renovations are taking place.
• Make sure children eat a well-balanced diet high in iron, protein, calcium, vitamin C, and zinc. Young children need frequent meals and snacks; they absorb less lead with something in their stomachs. Iron and calcium are especially effective at helping children absorb less lead. The human body mistakes lead for calcium and actually stores it in our bones. 
• The Centers for Disease Control recommend that all children be screened for lead poisoning at least once per year.