Lead Fact Sheet
Lead
Lead is a common element found throughout the environment in many different sources. It poses a significant health risk if too much enters the body. The risk is especially high for pregnant women and young children. In recent years media attention has focused on the potential dangers to children from lead in and around the home. However, lead poisoning is the oldest recorded occupational disease. The hazards of lead and its effects were known and documented in the 4th Century.
Sources
House Paints: Prior to 1950, lead-based paint was used on the inside and outside of most homes. It was used to make several colors, including white, and was known to dry to a hard durable surface. Though the use of lead in paint was reduced during the 1960's, it wasn't until 1977 that federal regulations virtually eliminated lead from paint for general use. Homes built prior to 1977 are likely to contain lead-based paint.
Soil: Soil near heavily-used streets and roads may contain lead as a result of past use of lead in gasoline. Lead may also be found in the soil next to houses where the exterior was painted with lead-based paint. Lead buildup in the soil can contribute to high levels of lead in household dust.
Drinking Water: Lead enters drinking water primarily as a result of corrosion or the wearing away of materials that are in the water supply system and household plumbing. These materials can include lead-based solder, brass and chrome plated faucets and in some cases, lead pipes that connect to the service line.
Additional Lead Sources: Old toys, some imported toys, lead-glazed and/or lead-painted pottery, leaded crystal, inks, plaster, hobby and sport activities where molten lead is handled (lead sinkers, ammunition, stain glass work, etc.), and clothing contaminated with lead from the workplace are all possible sources of lead.
Routes of Entry
There are two main ways lead can enter the body, inhalation and ingestion. Lead may be inhaled when it is burned or melted releasing some of the lead as a fume. Lead may also be inhaled when dust that contains lead becomes airborne (e.g., when a lead worker's contaminated clothing is worn to the worker's home or dry leaded paint is being removed from a surface.)
Lead may be ingested by small children when they eat lead paint chips or play in contaminated soil. Lead may also be ingested when cigarettes, food or food preparation surfaces become contaminated by lead containing dust. Lead may also be ingested through drinking water.
Health Effects
The effects of lead normally accumulate over time through a series of low level doses. There is a certain amount of lead present in our environment from past uses of lead called the background lead level. The amount of that background depends upon the history of the location.
We have all accumulated some lead in our bodies over the course of our lives. Lead may accumulate in almost all of our body tissues but only produces visible effects or symptoms when too much lead enters our bodies. The resulting disease is called lead poisoning.
Lead poisoning is normally treatable, though some of the effects can be permanent. Children under the age of 6 and fetuses exposed through lead in their mother's blood are most susceptible. Lead poisoning has been linked to anemia, central nervous system, kidney and immune system damage and learning disabilities. The degree of damage is dependent on the amount of lead taken into the body over time.
Signs & Symptoms
In Adults:
- headaches
- joint pain
- fatigue
- muscle ache
- nervousness
- poor appetite
- irritability
- impotency
- sleeplessness
- decreased fertility
- constipation
- miscarriage
In Children:
- irritability
- apathy
- loss of appetite
- abdominal pain
- clumsiness
- behavior problems
- learning disability
- constipation
severe symptoms:
- nausea/vomiting
- loss of balance
- stupor
- seizures
- coma
- blue tint to gums and skin under fingernails
In both adults and children, signs and symptoms are easily misdiagnosed. A child with lead poisoning may seem well. Symptoms usually do not develop until the condition is very serious. Symptoms of lead poisoning are easily confused with symptoms of other illnesses.
Positive Action
- Good housekeeping, parental supervision, and vigilant hygiene are essential in the prevention of lead exposure. Surfaces such as window sills, window wells and floors should be kept clean to prevent accumulation of lead-containing dust.
- Cover or repaint surfaces where lead bearing paint is cracking, chipping, chalking or peeling.
- Regularly wash children's hands to reduce exposure. Children are at the greatest risk when they put toys and other objects that may contain lead in their mouths.
- Since many symptoms of lead poisoning in children can be confused with symptoms of other illnesses, it is important to check with a doctor if you think lead poisoning may be the cause. The Centers for Disease Control (CDC) recommend that children between 0 - 6 years of age be tested yearly to determine the level of lead in their blood.
- Proper nutrition, complete with adequate amounts of iron and calcium, is important for children and may help decrease the amount of lead absorbed into the body.
- Never sand, burn or heat a surface that you suspect contains lead-based paint.
- Do not wear lead-contaminated clothing home from the workplace.
- Lead in drinking water cannot be seen, tasted or smelled. The only way to determine the level of lead in your water is to have it tested. A simple and inexpensive way to decrease the amount of lead in your water is: before using your tap water for drinking or cooking, let the cold water run for approximately one (1) minute to flush the tap. Water that has gone unused for five or six hours may contain lead leached from pipes or solders. Never cook or drink from the hot water tap. Hot water dissolves lead more quickly than cold water.
Lead-Based Paint Management Plan
University of Maryland has a Lead-Based Paint Management Plan which provides the criteria to be followed when working on lead-based painted structures on the University of Maryland campus. Only trained and protected individuals are permitted to disturb lead based-paint. All other personnel should contact the Department of Environmental Safety prior to the disturbance of painted surfaces unless it is known with certainty, either through documentation or testing, that the surface does not contain lead.
Regulatory and Recommended Exposure Limits
- The Occupational Safety and Health Administration (OSHA) limits workplace airborne exposure to 50 µg/m3 (micrograms lead per cubic meter air) averaged over an 8 hour workday. (Extended work days must be compared to a modified exposure limit of 400 µg/m3 ÷ hours worked per day.)(29CFR 1910.1025; 1926.62)
- OSHA limits the amount of lead carried in a lead worker's bloodstream to 40 µg/dL (micrograms lead per deciliter of blood). Employees with blood lead levels above 50 µg/dL must be removed from occupational contact with lead until the blood lead levels drop below 40 µg/dL. (29CFR 1910.1025; 1926.62)
- The Environmental Protection Agency (EPA) requires lead levels in ambient air to remain at or below 1.5 µg/m3 as averaged over a 3 month sample period. (40 CFR 141.80)
- EPA banned the sale of leaded gasoline in the USA as of 12/31/95.
- EPA recommends a maximum concentration of lead in drinking water of 15 µg/L (micrograms lead per liter of water) for 90% of the drinking water sources in an area. (40 CFR 50.12)
- The Centers for Disease Control and Prevention (CDC) recommends all children be screened for blood lead levels once per year, especially between the ages of 6 months and 6 years. Symptoms of lead poisoning often do not appear until the level of lead in the blood reaches 40 µg/dL or more. (CDC Lead Statement)
- CDC recommends that children who have a blood lead level at or in excess of 10 µg/dL (micrograms lead per deciliter of blood) be included in a childhood lead prevention program. (For more information contact the CDC lead Poison Prevention Program at 770-488-7330.)(CDC Lead Statement)
For further information contact the Department of Environmental Safety ((301) 405-3960).
Revision Date 7/97
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