Lead is a cumulative and persistent toxic substance that poses a serious health risk. It is a naturally occurring element found in small amounts in the earth’s crust. While lead does has some beneficial uses, it can be toxic to humans and animals, causing health effects. Below is a description of the characteristics, uses, and Permissible Exposure Limit (PEL), and Action Level (AL) for lead:
Click on the button below to see a video giving you an overview lead and its health effects.
We encourage you to visit the NIOSH Pocket Guide to Chemical Hazards - Lead webpage that contains chemical and physical properties and other information on lead.
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Although the focus of the course is on employees working in construction, it's important to understand that lead hazards can also affect each employee's family. With that in mind, we'll cover the effects of lead exposure on children as well as adults.
Lead is particularly dangerous to children because their growing bodies absorb more lead than adults do and their brains and nervous systems are more sensitive to the damaging effects of lead. Babies and young children can also be more highly exposed to lead because they often put their hands and other objects that can have lead from dust or soil on them into their mouths. Children may also be exposed to lead by eating and drinking food or water containing lead or from dishes or glasses that contain lead, inhaling lead dust from lead-based paint or lead-contaminated soil or from playing with toys with lead paint. See more.
Adults may be exposed to lead by eating and drinking food or water containing lead or from dishes or glasses that contain lead. They may also breath lead dust by spending time in areas where lead-based paint is deteriorating, and during renovation or repair work that disturbs painted surfaces in older homes and buildings. Working in a job or engaging in hobbies where lead is used, such as making stained glass, can increase exposure as can certain alternative (folk) remedies containing lead. A pregnant woman’s exposure to lead from these sources is of particular concern because it can result in exposure to her developing baby.
Click the button below to learn more about the hazards of lead exposure at home.
Lead paint is still present in millions of structures, sometimes under layers of newer paint. If the paint is in good shape, the lead paint is usually not a problem. Deteriorating lead-based paint (peeling, chipping, chalking, cracking, damaged, or damp) is a hazard and needs immediate attention.
If a building was built before 1978, there is a good chance it has lead-based paint. In 1978, the federal government banned consumer uses of lead-containing paint, but some states banned it even earlier. Lead from paint, including lead-contaminated dust, is one of the most common causes of lead poisoning. The older the structure, the more likely lead is present. About 24% of homes built between 1960-1977 contain lead. The number of homes containing lead increases to about 87% of all homes built prior to 1940.
Then click on the buttons below to see a list of additional sources of lead exposure and videos produced by the Wisconsin Department of Public Health discusses exterior and interior renovation practices. .
Lead in dust results from indoor sources such as:
Exposure to lead dust is common when old buildings are demolished. Even in well-maintained buildings, lead dust can form when lead-based paint is scraped, sanded or heated during home repair activities. Lead paint chips and dust can get on surfaces and objects that people touch. Settled lead dust can re-enter the air when the building is vacuumed or swept, or people walk through it.
To reduce exposure to lead dust, it is especially important to maintain all painted surfaces in good condition, and to clean frequently, to reduce the likelihood of chips and dust forming. Using a lead-safe certified renovator to perform renovation, repair and painting jobs is a good way to reduce the likelihood of contaminating your home with lead-based paint dust.
Click on the button below to learn more about the hazards of lead exposure in various workplaces.
In construction, lead is used frequently for roofs, cornices, tank linings, and electrical conduits. In plumbing, soft solder, used chiefly for soldering tinplate and copper pipe joints, is an alloy of lead and tin. Soft solder has been banned for many uses in the United States.
Construction projects vary in their scope and potential for exposing workers to lead and other hazards. Projects such as removing paint from a few interior residential doors may involve limited exposure. Others projects, however, may involve removing or stripping substantial quantities of lead-based paints on large bridges and other structures.
Workers potentially at risk for lead exposure include those involved in iron work; demolition work; painting; lead-based paint abatement; plumbing; heating and air conditioning maintenance and repair; electrical work; and carpentry, renovation, and remodeling work.
Plumbers, welders, and painters are among those workers most exposed to lead. Significant lead exposures also can arise from removing paint from surfaces previously coated with lead-based paint such as bridges, residences being renovated, and structures being demolished or salvaged. With the increase in highway work, bridge repair, residential lead abatement, and residential remodeling, the potential for exposure to lead-based paint has become more common.
Click on the button below to see a list of the those occupations at most risk of lead exposure.
Click on the button below to see a video on lead-based paint renovation and abatement.
Exposure to lead and lead chemicals can occur through four routes: ingestion, inhalation, dermal absorption, and trans-placental (endogenous) routes.
The two primary entry routes into the body for lead are ingestion (eating) and inhalation (breathing). A third, less significant entry route is through dermal (skin) absorption. Only certain organic lead compounds are absorbed through your skin.
When lead is scattered in the air as a dust, fume or mist it can be inhaled and absorbed through you lungs and upper respiratory tract. Inhalation of airborne lead is generally the most important source of occupational lead absorption. You can also absorb lead through your digestive system if you handle contaminated items or handle them with hands contaminated with lead.
Click on the buttons below for more information on each of these exposure routes.
Lead exposure in the general population (including children) occurs primarily through ingestion, making it the route that most commonly leads to elevated blood lead levels (BLLs). This includes swallowing a foreign body containing lead (i.e., jewelry, etc.).
From 20% to 70% of ingested lead is absorbed into the body, (with children generally absorbing a higher percentage than adults).
Inhalation is the second major pathway of exposure for the general population in the United States. The amount absorbed from the respiratory system depends on particle size, respiratory volume, amount of deposition, and the mucociliary clearance of the inhaled lead.
Dermal exposure does play a role for exposure to organic lead among workers, but is not considered a significant pathway for the general population.
Endogenous exposure to lead may contribute significantly to an individual's current BLL. Numerous reports document lead poisoning resulting from retained bullet or shrapnel fragments; thus, a history of military or other penetrating trauma may be important. If in a pregnant woman, this poses a particular risk to the developing fetus. Trans-placental exposure to the unborn child can happen if the mother is exposed to lead.
There is no sharp dividing line between rapidly developing acute effects of lead, and chronic effects which take longer to acquire. Lead adversely affects numerous body systems, and causes forms of health impairment and disease which arise after periods of exposure as short as a few days or as long as several years.
Acute, short-term overexposure. Lead is a potent, systemic poison that serves no known useful function once absorbed by your body. Taken in unusually large doses, lead can kill you in a matter of days.
Chronic, long-term overexposure. Long-term overexposure can lead to severe damage to your blood-forming, nervous, urinary and reproductive systems.
Click on the button below to watch a video on why lead is so bad for humans.
A significant portion of the lead that you inhale or ingest gets into your blood stream. Once in your blood stream, lead circulates throughout your body and is either filtered out of the body or stored in various organs and body tissues. As exposure to lead continues, the amount stored in your body will increase. Even though you may not be aware of any immediate symptoms of disease, stored lead can be slowly causing irreversible damage to cells, organs, and body systems.
Click on the button below to see the list of symptoms of chronic overexposure to lead and more information on .
Encephalopathy. Damage to the central nervous system in general and the brain (encephalopathy) in particular is one of the most severe forms of lead poisoning. The most severe, often fatal, form of encephalopathy may be preceded by vomiting, a feeling of dullness progressing to drowsiness and stupor, poor memory, restlessness, irritability, tremor, and convulsions. It may arise suddenly with the onset of seizures, followed by coma, and death.
Peripheral neuropathy. There is also a tendency for muscular weakness to develop. This weakness may progress to paralysis often observed as a characteristic "wrist drop" or "foot drop" and is a manifestation of a disease to the nervous system called peripheral neuropathy.
Kidney disease. Chronic overexposure to lead also results in kidney disease with few, if any, symptoms appearing until extensive and most likely permanent kidney damage has occurred. When overt symptoms of urinary dysfunction arise, it is often too late to correct or prevent worsening conditions, and progression to kidney dialysis or death is possible.
Reproductive systems. Chronic overexposure to lead impairs the reproductive systems of both men and women. Overexposure to lead may result in decreased sex drive, impotence and sterility in men. Lead can alter the structure of sperm cells raising the risk of birth defects. There is evidence of miscarriage and stillbirth in women whose husbands were exposed to lead or who were exposed to lead themselves. Lead exposure also may result in decreased fertility, and abnormal menstrual cycles in women.
Anemia. Overexposure to lead also disrupts the blood-forming system resulting in decreased hemoglobin (the substance in the blood that carries oxygen to the cells) and ultimately anemia. Anemia is characterized by weakness, pallor and fatigue as a result of decreased oxygen carrying capacity in the blood.
Each employee is responsible for reporting signs and symptoms of health problems. You should notify your employer if you:
In each of these cases your employer must make available to you appropriate medical examinations or consultations. These must be provided at no cost to you and at a reasonable time and place.
Measuring your blood lead level is the most useful indicator of the amount of lead being absorbed by your body. Blood lead levels (PbB) are most often reported in milligrams (mg) or micrograms (ug) of lead (1 mg=1000 ug) per 100 grams (100g).
Lead is toxic to both male and female reproductive systems. Lead can alter the structure of sperm cells and there is evidence of miscarriage and stillbirth in women exposed to lead or whose partners have been exposed. Children born to parents who were exposed to excess lead levels are more likely to have:
Workers who desire medical advice about reproductive issues related to lead should contact qualified medical personnel to arrange for a job evaluation and medical follow-up —particularly if they are pregnant or actively seeking to have a child. Employers whose employees may be exposed to lead and who have been contacted by employees with concerns about reproductive issues must make medical examinations and consultations available.
Under certain limited circumstances, a physician may prescribe special drugs called chelating agents to reduce the amount of lead absorbed in body tissues.
Click on the button below to learn about preventive measures.
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