One case report describes moderate exposure to inorganic lead while sandblasting lead-based paint for twelve-hours. Symptoms included headache, fatigue, nausea, abdominal cramps, and joint pain. Other health effects such as a metallic taste in the mouth, vomiting and constipation or bloody diarrhea might also be expected to occur. Harmful effects due to short-term exposure to inorganic lead compounds are rarely seen any more because of strict controls used in workplaces where lead exposure might occur.

Lead accumulates in the body and inorganic lead compounds are well known to cause significant health effects following long-term (chronic) exposure. If a significant amount of lead has accumulated in the body, symptoms of long-term toxicity may develop after what may seem to be a short-term acute exposure. For more information, refer to "What are the long term health effects of exposure to lead?" below.

Inorganic lead compounds are not known to cause skin irritation and are poorly absorbed through the skin.

There is no relevant human or animal information available. The dusts would probably cause some tearing, blinking and mild, temporary pain as the solid material is rinsed from the eye by tears. Concentrated solutions containing lead compounds or high levels of elemental lead fumes may also cause irritation.

Symptoms of ingestion of a very large dose over a short time period may include headache, fatigue, nausea, abdominal cramps, and joint pain. Other health effects such as a metallic taste in the mouth, vomiting and constipation or bloody diarrhea might also be expected to occur. Reports of effects following accidental, short-term ingestion in adults are very rare, particularly now that strict controls are used in workplaces where lead exposure might occur.

Cases of ingestion of inorganic lead compounds by children are commonly reported. Children are much more susceptible to the effects of lead than adults and, therefore, effects observed in children are not necessarily relevant to adults.

Long-term health effects of inorganic lead compounds, including elemental lead, are similar following inhalation or ingestion. Inorganic lead compounds are poorly absorbed through the skin.

Blood lead levels are often used as a general indicator of recent exposure to lead. As a result, blood lead levels, rather than airborne levels, are provided in most reports which discuss the potential health effects of exposure to inorganic lead compounds. The relationship between airborne lead levels and blood lead levels is complicated and depends many factors, including other sources of lead exposure and physical differences in individuals. Several studies indicate that an airborne exposure of 0.05 mg/m³ can result in blood lead levels of approximately 30-40 micrograms of lead/decilitre of blood (range 20-60 µg/dL).

Average blood lead levels of adults with no occupational exposure vary widely depending upon factors such as smoking habits, nutritional status, geographic area, and recreational exposures (for example, the use of firearms). In most industrialized countries, blood lead levels in adults without occupational exposure are typically less than 20-30 µg/dL. In this review, blood lead levels below 50 µg/dL are considered to reflect relatively low lead exposure; blood lead levels of 51-100 µg/dL reflect moderate lead exposure, and blood lead levels above 100 µg/dL would reflect high lead exposure. Many jurisdictions require that workers be monitored more closely or be removed from exposure if their blood lead levels exceed a certain level. Contact your regulatory jurisdictions for information.

Long-term lead toxicity is commonly referred to as "plumbism" and may include effects on the following body systems.

EFFECTS ON THE CENTRAL NERVOUS SYSTEM: Central nervous system (CNS) or brain function has been harmed in workers with long-term, low-level lead exposure. Symptoms typically occur with low to moderate exposure and include forgetfulness, irritability, tiredness, headache, fatigue, impotence, decreased libido (sexual drive), dizziness, and depression. Repeated exposure to moderate to high levels can cause encephalopathy (a progressive degeneration of certain parts of the brain). Early symptoms of encephalopathy include dullness, irritability, poor attention span, headache, muscular tremor, loss of memory and hallucinations. More severe symptoms occur at very high exposures and include delirium, lack of coordination, convulsions, paralysis, coma and death.

Repeated exposed to inorganic lead compounds can affect behaviour. Lead smelter workers with long-term exposure to low levels of lead have experienced altered mood states. Effects at moderate exposures include disturbances in hand-eye coordination, reaction times, visual motor performance, and mental performance.

Disturbances to vision have been observed in workers after months to years of overexposure to inorganic lead compounds. Symptoms range from very slight visual changes to a gradual decrease in vision, with slow recovery or, in some instances, progression to blindness.

Changes in hearing ability have also been reported in lead-exposed workers, particularly those with moderate to high exposure.

EFFECTS ON THE PERIPHERAL NERVOUS SYSTEM: Peripheral nerve function (nerves of the arms and legs) has been harmed in workers exposed to low to moderate levels of inorganic lead. Effects were shown to be reversible following a 5-month exposure. However, only partial recovery may occur, particularly if lead exposure continues or treatment is not carried out.

Peripheral neuropathy (e.g., loss of myelin which insulates the nerves) has been observed following long-term overexposure to inorganic lead compounds. This disorder is often referred to as "lead palsy" and symptoms include weakness of the arms and legs and weakness and paralysis of the wrist, fingers and ankles. Decreased hand dexterity (measured by finger tapping speed) has been reported in workers with low to moderate exposure to inorganic lead. Footdrop and wristdrop (an inability to hold the foot or hand extended) commonly occur with higher exposures.

EFFECTS ON THE DIGESTIVE SYSTEM: Effects on the gastrointestinal tract tend to be observed following high exposure to inorganic lead compounds, although they have sometimes been noted in workers with moderate exposure. Symptoms include loss of appetite, inflammation of the stomach walls (gastritis) and colic, with severe abdominal pain, cramps, nausea, vomiting, constipation, anorexia (loss of appetite), weight loss and decreased urination. In severe cases of lead exposure, a deposit of lead occurs in the gums near the base of the teeth. This deposit is visible as a blue-gray line.

EFFECTS ON THE KIDNEYS: Reversible kidney injury has been observed in some workers with repeated low exposure to inorganic lead compounds. Irreversible kidney damage has been observed following long-term, moderate exposures. An increased number of deaths due to kidney disease were observed in smelter and lead production workers with moderate lead exposure.

EFFECTS ON THE BLOOD AND HEART: Inorganic lead can cause harmful effects to certain types of blood cells, including reduced hemoglobin production and reduced life span and function of red blood cells. Reduced hemoglobin production has been associated with low-level exposure to inorganic lead in the workplace. Hemoglobin is the molecule responsible for carrying oxygen to body tissues.

With moderate exposures, anemia has been observed in lead-exposed workers. Low, moderate or high exposures to inorganic lead compounds may increase blood pressure, particularly in men. In two studies, electrocardiographic (ECG) abnormalities were observed in workers with moderate exposure to inorganic lead compounds.

EFFECTS ON THE THYROID AND THE IMMUNE SYSTEM: Whether or not long-term exposure to inorganic lead is associated with harmful effects on thyroid and immune system function has not been well studied yet and the available evidence is weak. In one study, firearm instructors with low exposure to inorganic lead had reduced numbers of some types of immune system cells. This observation is a very early indicator of impaired immune response. With moderate levels of exposure, workers had more colds and flu infections, but did not have impaired antibody production.

SKIN SENSITIZATION: Inorganic lead compounds are not known to be skin sensitizers. One case report describes a lead-exposed employee who developed dry, red, itchy skin (dermatitis). Patch testing with elemental lead was negative. This employee and another lead-exposed employee who had developed dermatitis tested positive in patch tests with two lead salts. These reports cannot be evaluated due to insufficient details.

The International Agency for Research on Cancer (IARC) has determined that the evidence for carcinogenicity of inorganic lead compounds to humans is inadequate and have classified these compounds as possibly carcinogenic to humans (Group 2B). A comprehensive review of more than twenty human studies involving workers exposed to inorganic lead compounds in battery industries, smelters, pigment factories, printing trades and the glass manufacturing industry concluded that there was a significant excess risk of overall cancer (stomach, lung, and bladder cancers), but not cancer of the kidney. The American Conference of Governmental Industrial Hygienists (ACGIH) has designated elemental lead as an A3 carcinogen (confirmed animal carcinogen with unknown relevance to humans).

Significant harmful effects have been reported in the male reproductive system following low to moderate exposures. Effects on the female reproductive system have not been clearly demonstrated following low to moderate inorganic lead exposure. Harmful reproductive effects have been reported in both men and women following high level exposures.

Despite limitations in human population studies, the overall literature suggests that low to moderate inorganic lead exposures are associated with significant male reproductive effects, such as low sperm count and abnormal sperm structure and mobility. In Yugoslavia, 101 male workers exposed to low to high levels of inorganic lead had reduced semen volume and density; reduced total, mobile and viable sperm; and increased numbers of abnormal sperm. Another study of 150 male workers with moderate to high, long-term exposure to inorganic lead compounds showed signs of reduced fertility, as measured by reduced viability of spermatozoa, low sperm counts and abnormal sperm structure. Similar effects have been observed in animal studies.

Associations between workplace exposure of the father and an increased rate of miscarriage or fetal death have also been reported. A critical review of the literature which relates these effects directly to the male (that is, through the sperm) indicates the information is limited and incomplete and that published results are conflicting. Therefore, no firm conclusions can be drawn. Historically, these effects have been related to poor hygiene procedures resulting in exposure of a pregnant woman to lead which has been carried home on her partner's work clothing. There are historical reports of reduced fertility and menstrual disorders in women with relatively high inorganic lead exposures. There are no recent human studies which meet current scientific standards. There is no relevant information available for elemental lead. Animal studies using lead acetate, a closely related chemical, are inconclusive.

Inorganic lead exposure during pregnancy has historically been associated with significant harmful effects on pregnancy, including increased miscarriages and stillbirths. Many of these historical reports involved exposure to very high levels of lead, as well as other environmental, social and lifestyle characteristics which may have caused or contributed to the observed effects. Lead exposure which has not also caused significant toxicity in the mother has not been clearly associated with teratogenic or embryotoxic effects (check out the glossaries of terms under the headings "MSDS - Common Terms" on the Chemicals & Materials web page).

Several non-occupational studies indicate that low to moderate exposure to lead during pregnancy and in early childhood, can produce harmful effects on neurobehavioural development and IQ, a measure of intelligence. Reduced birth weight and shorter pregnancy may also be related to low level lead exposure. However, this literature is inconsistent and no firm conclusions can be drawn.

There is no relevant animal information available for elemental lead. In studies with lead acetate, a closely related inorganic lead compound, neurobehavioural effects have occurred in offspring of rats at oral exposures which did not produce maternal toxicity.

Significantly increased kidney toxicity was reported in rats given the related chemical, lead acetate, and selected nitroso- or amide-type chemicals. Nutritional status and exposure to other metals such as calcium, phosphorous, iron, zinc and copper may influence inorganic lead absorption and toxicity.

Inorganic lead compounds are absorbed into the body following inhalation or ingestion. It is estimated that 30-50% of inhaled lead and that 5-15% of ingested lead is absorbed. The amount of lead absorbed is affected by many factors, including particle size (inhalation), as well as age, nutritional status and time of last meal (ingestion). Inorganic lead compounds are poorly absorbed through the skin. Once absorbed, inorganic lead compounds are distributed throughout the body. They can readily cross the placenta, reaching the unborn child. The majority of absorbed lead is excreted in the urine and feces. Small amounts are also excreted in sweat, hair, fingernails and breast milk. Some lead is not excreted, but is stored in the bones and accumulates in the body. It can take more than 20 years for half of the inorganic lead in the bones to be removed from the body. Lead which is released from the bones can cause health effects, even if there is no current exposure to lead. In some cases, lead can be rapidly released from the bones because of fractures, infections or other stresses on the body.