Appendix A to Section 5198 Substance Data Sheet for Occupational Exposure to Lead

(1) Short-term (acute) overexposure. Lead is a potent, systemic poison that serves no known useful function once absorbed by your body. With large enough doses, lead can kill you in a matter of days. A condition affecting the brain called acute encephalopathy may arise which develops quickly to seizures, coma, and death from cardiopulmonary arrest. A very high, short-term dose of lead can lead to acute encephalopathy. Short-term occupational exposures of this magnitude are highly unusual, but not impossible. Similar forms of encephalopathy may, however, arise from extended, chronic exposure to lower doses of lead. 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.

There is no sharp dividing line between rapidly developing acute effects of lead and chronic effects which take longer to develop. Lead adversely affects numerous body systems and causes forms of health impairment and disease which arise after periods of exposure as short as days or as long as several years. For example, short-term reproductive effects may include miscarriage and reduced birth weight of children exposed to lead during pregnancy. Both high and lower level lead exposures have been associated with these outcomes. Sperm abnormalities may develop at relatively high blood lead levels (at or above 20 micrograms of lead per deciliter of whole blood (µg/dl)).

(2) Long-term (chronic) overexposure. Chronic overexposure to lead may result in severe damage to your cardiovascular, blood-forming, nervous, urinary and reproductive systems. Damage to multiple organs may occur at blood lead levels previously thought to be without recognized harm. At higher lead levels, some symptoms of chronic overexposure include loss of appetite, metallic taste in the mouth, anxiety, constipation, nausea, pallor, excessive tiredness, weakness, insomnia, headache, nervous irritability, muscle and joint pain or soreness, fine tremors, numbness, dizziness, hyperactivity and lead colic. In lead colic there may be severe abdominal pain. Some people may not experience any symptoms even though lead is causing toxic effects in their bodies. It is important to note that for some people, permanent damage may occur even in the absence of symptoms.

Cardiovascular system (heart and blood circulation). Exposure to lead may cause increased blood pressure, heart disease, and stroke.

Neurologic system (brain and nervous system). Exposure to lead may cause declines in brain (cognitive) function, slowing of nerve conduction velocity, brain damage (encephalopathy), and nerve damage resulting in weakness or paralysis.

Renal system (kidneys). Exposure to lead may cause declines in kidney function that can progress to kidney failure requiring dialysis and to death.

Reproductive system. Chronic overexposure to lead impairs the reproductive systems of both females and males. The course of pregnancy may be adversely affected by exposure to lead since lead crosses the placental barrier and poses risks to developing fetuses. Reduced birth weight of children exposed to lead during pregnancy has been documented. Biological parents' lead exposure can harm the physical and mental development of a baby before birth. Lead exposure also may result in decreased fertility and abnormal menstrual cycles in females.

Exposure to lead may result in decreased sex drive, impotence, and sterility in males. Lead can alter the structure of sperm cells raising the risk of birth defects. There is evidence of miscarriage and stillbirth in females whose reproductive partners were exposed to lead or who were exposed to lead themselves.

Blood-forming system. Exposure 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.

(3) Health protection goals of the standard. Prevention of health damage for most employees from exposure to lead throughout a working lifetime requires that employee blood lead levels (BLL) be maintained as low as possible. The BLLs of employees who intend to have children should be maintained below 3.5 µg/dl to minimize adverse reproductive health effects.

The measurement of your BLL is the most useful indicator of the amount of lead being absorbed by your body. Your BLL is a measure of the amount of lead in your blood. This reflects both recent exposure as well as how much lead is stored in your bones. Past research into lead-related diseases has focused heavily on associations between BLLs and various diseases. As a result, your BLLs over time provide an important indicator of the likelihood that you will gradually develop a lead-related health impairment or disease.

As your BLL increases, your risk of disease increases. There is a wide variability of individual response to lead; thus, it is difficult to say that a particular BLL in a given person will cause a particular effect. Health damage has been found at chronic BLLs of 5 µg/dl and greater, including high blood pressure, reduced birth weight, and kidney dysfunction. At the other extreme, studies have associated fatal encephalopathy with BLLs of 150 µg/dl, but encephalopathy may occur at BLLs of 80 µg/dl. Your BLL is a crucial indicator of the risks to your health, but one other factor is also extremely important. This factor is the length of time you have had elevated BLLs. The longer you have an elevated BLL, the greater the risk that large quantities of lead are being gradually stored in your organs and tissues (body burden). The greater your overall body burden, the greater the chances of substantial permanent damage.

The best way to prevent all forms of lead-related health impairments and diseases (both short-term and long-term) is to maintain your BLL as low as possible. The standard is designed to detect BLL increases early and take action to control exposures.

Your employer has prime responsibility to ensure that the provisions of the standard are complied with both by the company and by individual employees. You as an employee, however, also have a responsibility to assist your employer in complying with the standard. You can play a key role in protecting your own health by learning about the lead hazards and their control, learning what the standard requires, following the standard where it governs your own actions, and seeing that your employer complies with provisions governing their actions.

(4) Reporting signs and symptoms of health problems. You should immediately notify your employer if you develop signs or symptoms associated with lead poisoning or if you desire medical advice concerning the effects of current or past exposure to lead on your ability to have a healthy child. You should also notify your employer if you have difficulty breathing during a respirator fit test or while wearing a respirator. 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. The standard contains a procedure whereby you can obtain a second opinion by a PLHCP of your choice if the employer selected the initial PLHCP.