Being a widely used and alarmingly harmful metal, lead has been the focus of toxicological research for many years. That research has found that even low levels of lead in a person’s blood can lead to lowered intelligence and learning disabilities, delayed puberty, hearing loss, reduced attention span, and behavioral abnormalities. According to the American Academy of Pediatrics, lead exposures are “a serious threat to children’s health” and “the best approach to lead poisoning is to prevent exposure in the first place.” Researchers and government agencies have concluded: “There is no ‘safe’ level of lead exposure.”

The developing brains of children are highly susceptible to the effects of lead. Lead exposures during pregnancy are of particular concern, as they can impair the intellectual development of a woman’s child, even at very low levels. These exposures occur not only from commonly recognized sources, such as lead paint chips, but also from lesser known sources of lead, such as clothing, toys, and food products. Because lead exposures are accumulative, EcoRights works to eliminate all possible sources of lead exposure.

Common Sources of Exposure

Traces of lead can now be found in all parts of our environment, and most are the 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 can cause a child lead poisoning many years later.

There are many ways to be exposed to lead. One 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 remains the most widespread and dangerous high-dose source of exposure.

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 source of lead exposure 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.

Some of the many other sources of lead exposure include:

• Water. Lead can leach into drinking water from certain types of plumbing materials, notably lead pipes, galvanized pipes, copper pipes with lead solder, and brass valves and faucets. 
  
  
• Products. Many common consumer products, particularly imported products, are sources of lead exposure, including those made of PVC plastics and leaded brass.
  
  
• Food. Food can be laced with toxic lead if it was grown in contaminated soil, processed using lead-tainted materials, or exposed to airborne lead dust.
  
  
• Hobbies. Certain hobbies use lead, such as ceramics and leaded-glass design, and traces can be deposited on clothes, hands, tools, shop surfaces, etc.
  
  
• Smoking. Tobacco smoke is a source of lead in the air if lead was an ingredient in the soil amendments used to grow the tobacco.
  
  
• Guns & ammo. 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.
  
  
• Radiation shielding. Some metal roofing and devices used to shield from X-rays contain lead.
  
  
• Batteries. Batteries and battery terminals 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. 

Lead's 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, children suffer the greatest environmental health risks from lead. 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 can decrease reaction time, cause weakness in fingers, wrists, and ankles, and possibly affect memory. It might 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

Most people who are lead-poisoned have no symptoms at all. The problems only become obvious at higher levels of exposure, even though small amounts are known to cause serious long-term health effects. Symptoms are often subtle and attributable to other things. In children, symptoms include irritability, tiredness (reduced play activity), loss of appetite, abdominal pain, muscle aches, vomiting, diarrhea, constipation, and headaches. Adults might notice effects on libido, fertility (in males), and blood pressure, which can be elevated. (High blood pressure, or hypertension, increases the risk of heart attack and stroke.)