| Lead poisoning |
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Facts Tap water in 4,500 Boston properties flows through aging lead pipes that could be exposing city residents to higher lead levels than is allowed by federal law. Lead levels in most of those homes are unknown, but the results of tests on a tiny sampling of the properties, released yesterday by the Massachusetts Water Resources Authority, found some with lead levels that exceeded federal standards. Overall, the 47-community system is in compliance with federal standards, but nine communities, including Boston, had some properties that exceeded the standard, according to a sample from 440 homes. The authority's small sampling in Belmont, Framingham, Malden, Medford, Norwood, Quincy, Somerville, and Watertown also showed levels of lead exceeding the 15 parts per billion allowed by law. The Conservation Law Foundation requested the addresses of all the properties in Boston with lead pipes and mapped those addresses, comparing the neighborhoods that have high concentrations of lead piping with neighborhoods where childhood lead poisoning is known to be high. Across Boston last year, 647 children under the age of 6 were known to have lead poisoning, a sharp reduction since 1993, when more than 5,000 children had lead poisoning. Overview Concern over the health risks of lead poisoning, especially to children, isn't new. Although lead is no longer used in paints, gasoline, water pipes and other products, some lead-based products still exist and may pose a health hazard. In the United States, deteriorated lead-based paint in older homes and high levels of lead-contaminated house dust are the most common sources of lead poisoning in 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 is toxic to many of your body's tissues and enzymes. It can enter your body when you breathe, drink or eat anything that contains lead. With the exception of certain organic lead compounds, such as tetraethyl lead, previously added to produce leaded gasoline, you don't absorb lead through your skin. It accumulates in the bone marrow, nerve tissue - including your brain - and kidneys. You excrete some lead in urine and stool. Children particularly are susceptible to lead poisoning because it can accumulate in their nervous system as their bodies grow and develop. Although death by lead poisoning is uncommon, dangerous levels of lead in children may cause serious health problems, including lowered intelligence and poor school performance. According to the most recent CDC estimates, more than 400,000 children ages 1 to 5 years living in the United States have levels of lead in their bodies high enough to cause concern. Unfortunately, lead poisoning may go undetected because frequently there are no obvious symptoms. But by removing or avoiding lead sources or with early detection and treatment, you can prevent or limit the harmful effects of lead poisoning. 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 in the body usually is gradual, building up unnoticed until levels are dangerous. The signs and symptoms The signs and symptoms of lead poisoning in children are nonspecific and may include:
Although children are primarily at risk, lead poisoning is also dangerous to adults. The signs and symptoms of lead poisoning in adults may include:
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 dramatic 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 1986 and again in 1988, 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. 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.
Risk factors Children and adults living in or surrounded by an environment with lead-based products are at risk of exposure to high lead levels. 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 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 caution 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 are measured in the blood in micrograms per deciliter. An unsafe level is 10 micrograms or more per deciliter - 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. In March 2000, a 2-year-old girl died of lead poisoning. Investigators concluded that lead paint and dust in her New Hampshire home probably was the source of poisoning. This was the first reported death of a child caused by lead poisoning in the United States since 1990, according to the CDC. Health problems in children caused by exposure to low levels of lead may include:
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:
Treatment 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. To reduce lead in your body, your doctor may recommend chelation therapy. In chelation therapy, you receive a chemical called ethylenediaminetetraacetic acid (EDTA) through injections in your veins (intravenously). The EDTA binds with the lead so that it's excreted from your body. Depending on your lead level, you may need a large number of treatments. And 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 only checks for lead content of 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 or more per deciliter, 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 micrograms or more per deciliter, 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:
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 by sanding. Sanding is hazardous because it generates large amounts of small particles that wind up on the floor, where small children might encounter it. 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 inhalable. 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. |
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