Lead Poisoning

Problem Overview
Concern over the health risks of lead poisoning, especially for children, isn't new. Lead is no longer used in paints, gasoline, water pipes and other products, but some lead-based products still exist and may pose a health hazard.

Lead is toxic to many of your body's tissues and enzymes. Children particularly are susceptible to lead poisoning because it can accumulate in their nervous system as their bodies grow and develop. Death by lead poisoning is uncommon, but dangerous levels of lead in children may cause serious health problems, including lower intelligence and poor school performance. An estimated more than 400,000 U.S. children 5 years old or younger have levels of lead in their bodies high enough to cause concern.

Deteriorated lead-based paint in older homes and high levels of lead-contaminated house dust are the most common sources of lead poisoning in U.S. children. Lead paint is present in an estimated 24 million U.S. homes. More than 4 million of these are homes to one or more young children, according to the Centers for Disease Control and Prevention (CDC).

Lead poisoning may go undetected because frequently there are no obvious signs or symptoms. By removing or avoiding lead sources or with early detection and treatment, you can prevent or limit the harmful effects of lead poisoning.

Signs and symptoms
Lead poisoning may be hard to detect at first, because children who appear healthy can have high levels of lead in their bodies. The accumulation of lead usually is gradual, building up unnoticed until levels become dangerous and cause signs and symptoms.

Signs and symptoms in children
The signs and symptoms of lead poisoning in children are nonspecific and may include:

• Irritability
• Loss of appetite
• Weight loss
• Sluggishness
• Abdominal pain
• Vomiting
• Constipation
• Pallor from anemia

Signs and symptoms in adults
Although children are primarily at risk, lead poisoning is also dangerous to adults. The signs and symptoms of lead poisoning in adults may include:

• Pain, numbness or tingling of the extremities
• Muscular weakness
• Headache
• Abdominal pain
• Memory loss
• Reproductive impairment in men

Causes
Lead isn't biodegradable and can remain a health threat if it's not properly removed or contained.

Sources of lead contamination

• Soil. In 1978, the Environmental Protection Agency (EPA) reduced the level of lead allowed in gasoline. This led to a large decline in the number of children with elevated levels of lead in their bloodstream. But lead particles that settle on the soil from gasoline or paint used years ago can remain there for many years. High concentrations of lead in soil can be found around major highways and old homes and in some urban settings.
• Household dust. Household dust can contain lead from paint chips or soil brought in from outside. The Consumer Product Safety Commission (CPSC) banned the sale of lead-based paint in 1978, but lead may be present in homes built before then. About two-thirds of homes built before 1940, half of homes built between 1940 and 1960, and a lesser number of homes built between 1960 and 1978 contain lead paint, according to the National Safety Council.
• Water. In the 1980s, Congress changed the Safe Drinking Water Act to restrict the use of lead in pipes, solder and other components used in public water systems. Lead pipes, brass plumbing fixtures and copper pipes soldered with lead can release lead particles into tap water. If you have such plumbing, let cold water run 30 to 60 seconds before drinking it. Hot water absorbs more lead than cold water does. The EPA warns against making baby formula with hot tap water from old plumbing systems.
• Lead paint. In 1978, the CPSC banned the sale of lead-based paints for use in residences, children's toys and household furniture. However, lead-based paint is still on walls and woodwork in many older homes and apartments. Glazes found on ceramics, china and porcelain may contain lead, as well.
• Some imported canned food. In 1995, the United States banned the use of lead solder for sealing food cans, but some foods still are imported from other countries where lead solder may be used.
• Traditional remedies. Some cases of lead poisoning have been traced to the use of certain ayurvedic medications, traditional medicines from India and other South Asian countries that may contain lead. The Food and Drug Administration (FDA) has also warned that litargirio - a peach-colored powder popularly used in the Dominican Republic as deodorant, foot fungicide and treatment for burns and wounds - contains very high levels of lead and should not be used.
• Kohl. Kohl is a traditional cosmetic, often used as eyeliner. But testing of various samples of kohl frequently revealed high levels of lead, sometimes more than half the weight of the sample.

Risk factors
Children and adults living in or surrounded by an environment containing lead-based products are at risk of exposure to high lead levels.

• Children who are most at risk. Babies and young children especially are susceptible to lead exposure because they have a tendency to put objects in their mouths. They may eat or chew paint chips, or their hands or other objects placed in their mouths may be contaminated with lead dust. Lead poisoning is more dangerous to fetuses, babies and children than to adults because lead is more easily absorbed into growing bodies. The tissue of children also is more sensitive to lead's damaging effects. Although lead exposure can affect any child, those who are most at risk are low-income children who live in older housing, usually in inner city areas.
• Adults who are most at risk. Adults may breathe in lead dust while remodeling a home, while working on certain jobs with lead exposure or while engaging in a hobby, such as making stained glass or refinishing furniture. If you're pregnant, take extra precautions, because lead can damage your developing fetus.

Screening and diagnosis
Doctors use a blood test to detect lead poisoning. A small blood sample is taken from a finger prick or from a vein. Lead levels in the blood are measured in micrograms per deciliter (mcg/dL). An unsafe level is 10 mcg/dL or higher - a guideline set by the CDC. The CDC recommends having your child tested for lead poisoning at 6 months and then yearly if your home contains lead paint, or if you're exposed to lead at work or use lead in your hobby.

Complications
Exposure to even low levels of lead can cause permanent damage. The greatest risk is to brain development, where irreversible damage may occur. High lead levels in children may cause seizures, unconsciousness and possibly death. Death by lead poisoning in children is rare, but it can happen.

Complications in children
Health problems in children caused by exposure to low levels of lead may include:

• Nervous system and kidney damage
• Learning disabilities
• Speech, language and behavior problems
• Poor muscle coordination
• Decreased muscle and bone growth
• Hearing damage

Complications in adults
Although lead poisoning is especially dangerous to children, it may cause health problems in adults, too. High levels of lead in adults may lead to complications such as:

• High blood pressure
• Digestive problems
• Nerve disorders
• Memory and concentration problems
• Muscle and joint pain
• Damage to sperm-producing organs in men
• Cataracts

Treatment
Lead levels in the blood are categorized into Classes I through V. Class V is the most severe and constitutes a medical emergency. The classes are as follows:

• Class I: less than 10 micrograms per deciliter (mcg/dL)
• Class II-A: 10 to 14 mcg/dL
• Class II-B: 15 to 19 mcg/dL
• Class III: 20 to 44 mcg/dL
• Class IV: 45 to 69 mcg/dL
• Class V: 70 or greater mcg/dL

The primary treatment for lead poisoning is to stop the exposure. Removal of the source of lead is critical to reducing the lead levels. If you can't remove the source of lead from the environment, you may have alternatives to reduce the likelihood that lead will cause problems. For instance, sometimes it might be preferable to seal in, rather than remove, old lead paint. Your local health department can recommend resources to identify and reduce lead in your home or in your community. For Classes I and II, ceasing exposure to lead may be sufficient to reduce lead in your body.

Treating higher classes
For more severe cases, your doctor may recommend chelation therapy in addition to removal from lead exposure. In chelation therapy, the medicine (chelating agent) you take binds with the lead so that it's excreted from your body. Some Class III cases and many Class IV cases may be treated with the oral drug succimer (dimercaptosuccinic acid).

Lead levels greater than 45 mcg/dL of blood, which fall into Class IV or V, are treated with a chemical called ethylenediaminetetraacetic acid (EDTA). EDTA is administered through injections in your veins (intravenously) and may be combined with the drug dimercaprol (BAL). Depending on your lead level, you may need more than one treatment. The therapy may not reverse damage that already has occurred in cases of severe lead intoxication.

Prevention
You can take some simple measures to reduce or offer protection from lead poisoning. These may include:

• Lead assessment. The first step you can take to reduce the hazard of lead poisoning is to have a professional check your home for lead hazards. Two methods include a lead inspection done by a lead inspector and a risk assessment done by a risk assessor. Home lead tests are available but the EPA doesn't recommend them because they may not be reliable.
• Lead inspection. The limitation of a lead inspection is that it checks only for lead presence in painted surfaces in your home and doesn't determine whether the paint has dangerous levels of lead.
• Risk assessment. This may be a better alternative because a risk assessment tells you if your home contains dangerous lead sources, such as peeling paint, and tells you how to reduce or control the hazards.

If you live in an apartment and your child has a blood lead level of 20 micrograms per deciliter (mcg/dL) or higher, your landlord may be required to take certain actions, depending on your local laws and regulations. If you live in public housing, you should have received a brochure from the housing authority regarding the possibility of exposure to lead-based paint. If your child has a blood lead level of 25 mcg/dL or higher, the housing authority must test your residence within five days of being notified by your doctor. If lead-based paint is found in your apartment, the housing authority must correct the problem within 14 days or move your family into a unit that was previously treated or built after 1978.

Everyday tasks
If you live in or near an area that contains lead, you can help reduce the risk of lead hazards by practicing the following suggestions:

• Wash your children's hands after they play outside, before eating and going to bed.
• Clean your floors with a wet mop and wipe furniture, windowsills and other dusty surfaces with a damp cloth.
• Don't let your children play near major roadways or bridges.
• Prepare meals that are high in iron and calcium. A nutritious diet helps prevent lead absorption in your children's bodies.
• Run cold water for at least a minute before using, especially if it hasn't been used for a while. Don't use hot tap water to make baby formula or for cooking.

Home renovation
If you're doing minor remodeling or touch-up work in an older house with lead-based paint, take some precautions.

• Wear protective equipment and clothing.
• Change your clothes, take a shower and wash your hair before leaving the job.
• Don't shake out work clothes or wash them with other clothes.
• Be careful where you eat. Don't eat or drink in an area where lead dust may be present.
• Don't attempt to remove the lead paint by sanding. Sanding surfaces painted with lead is hazardous because it generates large amounts of small particles that wind up on the floor, where small children might encounter them. If you must sand, some types of sandpapers are designed to hold together when wet. Sanding with wet sandpaper helps reduce dust.
• Don't use an open-flame torch to remove paint. The flame produces lead particles small enough to inhale. Inhalation is an even more hazardous route of exposure than oral ingestion.
• Don't use the highest setting on a heat gun. People use heat to soften up paint to make it easier to remove. Some heat guns may get hot enough to make lead particles able to be inhaled. If you're using a heat gun with settings on it, avoid the highest settings.
• Use caution in painting over old lead paint with new, lead-free enamel. Proper removal of intact lead paint may not be feasible. If the paint is on tight, without many chips, then it should stay that way and you can paint over it. You can also use paneling, drywall or encapsulation, which is similar to a very thick coat of paint. Large home renovation projects may require you to move out of your home until the project is complete and a professional can determine whether the lead no longer is a hazard.

Courtesy article provided by www.mayoclinic.com