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Health Effects of Lead. Lead-Safe Weatherization for Crews and Managers. WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – September 2012. Describe lead poisoning and understand how much lead is dangerous to the body. Explain methods through which lead can enter the body.
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Health Effects of Lead Lead-Safe Weatherization for Crews and Managers WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – September 2012
Describe lead poisoning and understand how much lead is dangerous to the body. Explain methods through which lead can enter the body. List the different effects of lead on children and adults. Describe how blood lead levels are measured. Summarize OSHA worker protection standards related to lead. Learning Objectives
Possible Sources of Lead • Imported pottery • Water pipes • Mini-blinds • Painted toys • Painted furniture • Craft products • Others Image courtesy of Mike Vogel Photo courtesy of the Centers for Disease Control Photo courtesy of CPSC Photo courtesy of the Cincinnati Children's Hospital Image courtesy of Mike Vogel Photo courtesy of the Centers for Disease Control
What is Lead Poisoning? • Lead poisoning refers to the health effects associated with an abnormally high level of lead in the blood stream. • Symptoms of lead poisoning may develop quickly but are often not recognized until severe damage is done. • These symptoms of lead poisoning are often mistaken for the flu. • In cases of chronic lead poisoning, the symptoms may come and go for months. • A child can seem healthy because the symptoms do not develop until the condition is serious and significant irreversible damage is already done. Photo courtesy of the U.S. EPA
How Long Can Lead Remain in the Body? • Once lead gets into the body, it stays in the blood for several weeks and can be stored in the bones for 30 years or more. • The more lead a person is exposed to, the greater the chance for lead poisoning. • Many small doses of lead over a long period of time can cause lead poisoning. • One large dose of lead in less than a day can cause lead poisoning.
How is Lead in the Body Measured? • Blood tests are the only way to measure lead exposure. • The amount of lead in the body is the Blood Lead Level (BLL). • BLL is measured in micrograms (µg) of lead per deciliter (dL) of blood. • A microgram is equal to one single grain of sugar cut into 1,000 pieces. • A deciliter, a volume measure, is equal to a little less than half a cup. A person weighing 165 pounds has about 60dL of blood. Photos courtesy of Mike Vogel
How Much Lead is Dangerous? • How much lead is dangerous? • According to the Centers for Disease Control and Prevention (CDC) 5 µg/dL is the “blood lead level of concern”. • The Occupational Safety and Health Administration (OSHA) requires the medical removal of workers whose blood lead level reaches 50μg/dl or greater. • The typical level for U.S. adults is less than 10 µg/dL (mean = 3 µg/dL).
How Does Lead Get into the Body? • The chemical properties of lead are similar to the properties of calcium, a necessary nutrient, and are therefore readily absorbed by the human body. • Those who lack calcium and iron in their diets absorb more lead. • Children and pregnant women absorb up to 50% of the lead they ingest or inhale. • The rest of the population absorbs 10-15% of ingested or inhaled lead.
Lead Enters the Body in Two Ways: • Inhalation (breathed in): Tiny lead particles in dust or fume form can be breathed into the lungs and absorbed into the blood stream. • Ingestion (swallowed): Lead can be swallowed if it is airborne or if it is on food, fingers, cigarettes, toys, or anything that is placed in the mouth. Lead that is inhaled but does not reach the lungs, can be trapped in the upper respiratory tract and is eventually swallowed.
Lead and Children • Lead is the foremost environmental health threat to children. Since children have a much smaller body mass, similar exposures between a child and an adult, yield a much higher dose in the child. • Almost one million children have enough lead in their blood to reduce intelligence and attention span. • Minority and low-income children are at a greater risk for lead poisoning than other population groups. • They generally live in older housing units. • They often have poor diets. • To keep from worsening the situation, Weatherization Programs serving this population must implement lead-safe Weatherization LSW practices in all homes built before 1978.
How Does Lead Affect the Body? The Heart and Blood • Lead kills red blood cells through oxygen depravation. • It reduces the ability to generate new red blood cells resulting in anemia. • Lead may cause high blood pressure which increases the risk of heart attack, stroke, and kidney disease.
The Skeletal System • Lead is deposited in bone tissue where it blocks the production of new blood cells and competes with calcium. • Bones and teeth store 95% of the lead in the body. If lead is in the bones instead of calcium, it can be re-released into the blood when the body needs calcium as often occurs when the body is stressed. • Once the lead returns to the blood, it once again causes damage. • Lead that stays in the body is called body burden.
The Male Reproductive System • Lead poisoning causes decreased sex drive, erectile dysfunction, infertility, and damaged sperm. • Partners of lead-poisoned workers have more miscarriages, premature births, and their children are more likely to have more birth defects.
The Female Reproductive System • Lead poisoning causes decreased sex drive, abnormal menstrual cycles, infertility, miscarriages, and premature births. • During pregnancy, the body absorbs up to 50% of inhaled or ingested lead. Lead stored in the skeletal system can be re-released. • Lead damages fetuses causing low birth weight, birth defects, learning problems, and behavioral problems.
The Nervous System • Damage to the brain, spinal cord, and nerves can be permanent. • Lead poisoning can cause brain damage. • At very high doses, lead can cause hallucinations, swelling of the brain, coma, and death. • Lead damage to nerves usually starts at the hands and feet which may shake or, in severe cases, may become paralyzed. • The nervous system of a fetus, infant, or child is affected by even smaller amounts of lead.
The Kidneys • Kidneys help to filter out lead from the blood system. • Lead damages the kidneys as the filtration process occurs. • Damage is not usually discovered until significant function has been lost. • Lead poisoning can cause kidney failure and result in death.
Worker Protection - OSHA • Even if DOE and EPA did not have rules dealing with lead exposure to workers, implementing Lead-Safe Weatherization, the Occupational Safety and Health Administration (OSHA) is an agency of the Department of Labor which writes and enforces rules protecting workers on the job. • To protect employees from lead hazards, the OSHA Lead in Construction Standard (29 CFR 1926.62) was developed. The standard became law on June 3, 1993.
Action Level • OSHA Lead in Construction Standard (29 CFR 1926.62) set two legal limits for the amount of lead workers are allowed to breathe. • Action Level: • The Action Level for lead is 30 micrograms per cubic meter (μg/m3). The Action Level is like a yield sign. It means caution! If average 8-hr exposure is over 30 µg/m³ the employer must train the workers on the hazards of working with lead and provide special medical exams called medical surveillance.
Permissible Exposure Level • Permissible Exposure Level: • The permissible Exposure Limit (PEL) for lead is 50 μg/m³. • The PEL is like a stop sign, it means go no higher! • The employer is not allowed to let workers inhale lead in concentrations of more than 50 μg/m³ of air without proper protection. • If the workers are in an area with more lead in the air than the PEL, the employer must reduce the exposure. The PEL is the highest average amount of lead exposure allowed for workers.
OSHA Required Protection and Responsibility • To protect workers from exposure to airborne levels of lead above the PEL, the employer must implement strategies to reduce the exposure. Such strategies include: • Training on lead hazards. • Work practice and engineering controls (containment, HEPA vacuum, shrouded tools). • Protective clothing. • Protective equipment. • Respirators. • Medical surveillance.
Summary – What is Lead Poisoning • Health effects associated with an abnormally high level of lead in the blood. • The signs and symptoms are much like those of a cold or the flu. • Sometimes there are no symptoms until the damage is significant. • Sometimes the symptoms come and go.
Summary – How Does Lead Get into the Body? • Lead dust particles or fumes can be inhaled. • Children are at a higher risk because they have more frequent hand-to-mouth contact. • The major source of exposure for children is lead dust. • Children and pregnant women absorb up to 50% of the lead they ingest of inhale. • Non pregnant adults typically absorb about 10-15% of the lead ingested or inhaled.
Summary – How Does Lead Harm the Body? • Lead can cause permanent damage, even in small doses. • Children’s developing brains and bodies are easily damaged by lead. • Lead affects EVERY major organ in the body system. • Lead can stay in the blood stream for several months and in the bones for more than 30 years. • Lead can be released from the bones during times of stress. • Lead can cause still births and miscarriages. • Lead can cause behavioral, developmental, and learning problems in children.
Summary – How Much Lead…? • How is lead measured in the body? • Blood tests determine how much lead is in the blood. • Results of blood tests are called “Blood Lead Levels (BLLs).” • Blood Lead Levels are reported in μg/dL (micrograms of lead per deciliter of blood). • How much lead in the blood is dangerous? • The CDC’s reference lead level for children is 5 μg/dL. • At 50 μg/dL, OSHA requires that a worker be removed from a lead-related task until Blood Lead Levels are reduced. • Even relatively low lead levels in blood can cause serious health problems.