Molds | Lead | Pesticides | Mercury | Parents Page * The information on this website should not be taken as medical advice, which can only be given to you by your personal health care professional.

What is lead?
Lead is a heavy metal that is naturally distributed in small amounts on the surface of the earth. Our body has no biological need for lead. However, lead acts like calcium in the body and is stored mostly in the bones. Lead exposure is still among the most important environmental health problems for young children in the U.S. and worldwide.

Lead in gasoline used to be the most important source of lead exposure for the U.S. population. However, since lead was removed from gasoline in the early 1970’s, the nation’s average blood lead level has decreased dramatically. This reduction in lead levels has been considered one of the genuine public health success stories of modern times. ⁶

How can my child or I be exposed to lead?
Much of the lead released into the environment results from human activities such as mining, manufacturing processes, and burning of fossil fuels. There are three main ways that people can still be exposed to lead: in the general environment, in the workplace, and in the home.

1. Sources of lead exposure in the general environment include: ⁴
   • Food grown on soil contaminated with lead or covered with lead dust
   • Water carried by lead pipes or pipes with lead soldering
   • Lead-contaminated air or dust near a hazardous waste site
   • Smoke from cigarettes contaminated with lead
2. Sources of lead exposure in the workplace include:
   • Workplace air in industries such as lead refining, battery manufacturing, and construction.
3. Sources of lead exposure in the home include:
   • Eating or breathing paint chips or dust contaminated with lead, especially in homes built before 1977.¹
   
   
   • Drinking water carried by lead pipes or with lead soldering. This is a problem in many older homes.¹
   
   
   • Certain hobbies such as making stained glass, glazed pottery, remodeling of older homes, etc.⁴
   
   
   • Toys or pottery containing lead-based paints.²
   
   
   • Certain folk remedies. ²
   
   
   • Lead-containing cosmetics such as surma and kohl^{22, 23}
   
   
   • Some calcium supplements made from bone or oyster shell. ²

Children are generally considered to be at increased risk of lead exposure compared to adults for a variety of reasons:

1. Their behavior — compared with adults, children:
   • have an increased tendency to place toys, dirt, or paint chips in their mouth.
   • are closer to the ground and may be more likely to come in contact with contaminated objects on the floor.
   • are more likely to play with dirt and soil.
2. Their bodies — compared with adults, children:
   • absorb lead from water, air, and food better than adults.
   • have brains that are actively growing. Several studies have shown that lead alters the development of growing brain cells.^{11, 26-30}
   • have a less developed barrier between the blood and the brain, allowing relatively more lead to pass into their developing brains.  Also, studies have suggested that lead itself acts to disrupt this barrier. ²⁵
   • are more likely to show health effects from the same amount of lead exposure, even at relatively low levels.

Due to these factors, the child’s developing brain presents a biological window of vulnerability to lead.

What are the health effects of lead?
Lead can affect many body systems in both children and adults. The health effects of lead depend upon the amount of exposure, which is determined by three factors: intensity, duration, and timing.

Intensity refers to the relative degree of exposure (small, moderate, or large) at any given time. Duration refers to the time course over which the exposure occurs (days to years). Timing refers to the developmental stage at which the exposure occurs. Another important factor that may influence the health effects of lead exposure is the nutritional status of the child. It has been shown that diets low in calcium and iron can actually increase the amount of lead the body absorbs.^{24, 32, 33}

We will discuss the health effects resulting from two types of lead exposure: acute high-level, and chronic low/moderate-level.

Acute high-level:
The health effects of this type of exposure have been studied in both occupational and general environmental settings.These types of exposures are rare events in this day and age in the U.S. Children and adults exposed to such levels of lead may show the following health effects³:

• Memory Problems
  
• Seizures
  
• Confusion
  
• Clumsiness
  
• Changes in behavior
  
• Muscle weakness
  
• Severe abdominal pain
  
• Constipation
  
• Kidney failure

Chronic low/moderate level:
The health effects of this type of exposure have been mostly gathered in studies of large groups of children. Children are considered to have a much greater risk of health effects from lower level exposure to lead than adults.

U.S. children are more likely to experience chronic low/moderate-level lead exposure than acute, high-level exposure. Chronic, lower/moderate-level exposure may also produce some of the same symptoms associated with higher levels of exposure (abdominal discomfort, constipation, fatigue, etc). However, the most important problems caused by these levels of lead in children are problems with brain development.¹

Chronic lower/moderate-level lead exposure may cause the following problems in adults or children:

Nervous System –
·learning deficiencies^{, 12, 16}
·decreased intellectual function^{12, 14, 19}
·memory problems^{12, 10, 16}
·problems with behavioral or attention^{15, 18, 20, 21}
·problems with coordination^{18, 31}

Blood-making System –
·anemia (not enough blood cells to carry oxygen)^{3, 29, 30}

Digestive System –
·constipation or diarrhea^{3, 34}
·abdominal discomfort^{3, 34}

Renal System (kidneys) –
·elevated blood pressure³³⁵
·abnormal kidney function^{3, 35, 36, 37}

Reproductive –
·abnormal reproductive function ³
·possible infertility

Given our increasing scientific knowledge, the levels of lead thought to be associated with negative health effects have been dropping in recent years.⁸ However, it is important to understand that the relationship between lead levels and negative health effects is seen on a population level, not at the individual level. In most cases, it is difficult to determine whether moderately increased lead levels caused a developmental problem in an individual child.

Is there a medical test to see if my child has a high lead level?
There are medical tests available which can determine the lead levels in blood, hair, and bone. Lead in teeth and bones can be measured with X-rays, but this test is not readily available. The blood test is the most widely used in clinical practice. However, it can only show the lead exposure within the past few months.⁴ There are also tests available which can determine the amount of lead present in the soil, water, or air.

The level of lead in the blood is most often used as the measure of the amount of lead in the body. The Centers for Disease Control and Prevention have established a blood lead level of 10 micrograms per deciliter of blood (10 ug/dL) as its “level of concern.” Levels greater than this are more likely to cause the previously described health effects.

If you suspect your child has been exposed to high levels of lead, your health care provider or local health department can check your child’s blood lead level.

What can I do to decrease my child’s exposure to lead?

• If you have an older home with lead-based paint, get professional help to have this paint removed safely.
  
• If your home has lead-containing pipes, let the water faucet run for a few minutes in the morning before using the water for drinking or cooking.
  
• If your home may have lead-contaminated dust, wet mop rather than dry mop floors. This will help decrease the contaminated floor dust.
  
• Encourage kids to wash their hands often.
  
• Make sure your child eats a diet with plenty of calcium and iron. Foods high in iron include cheese, meat, eggs, spinach, beans, etc. Foods high in calcium include milk, cheese, beans, broccoli, etc.
  
• Avoid old ceramic pottery and cookware. These may contain lead-based paints.
  
• If your cultural or religious practice involves the use of cosmetics such as surma or kohl, purchase lead-free cosmetics instead. These products are available in your local retail store.
  
• If any adults in the household work with lead, be sure they change from their work clothes and work shoes before entering the house.
  
• If any adults in the household have a hobby that involves lead, be sure that the work area is well ventilated. Also be sure that supplies are stored securely.
  
• Avoid folk remedies that contain lead.