Inorganic lead, occupational exposure

Because of the toxicity of lead, special care must be taken when working with lead ahoys. Lead and its inorganic compounds are neurotoxias which may produce peripheral neuropathy. Eor an overview of the effects of lead exposure, see Occupational Exposure to Lead, Appendix A (29 CRE 1910.1025) (see... 

Deaths associated with occupational exposure to inorganic lead (which is predominantly by the inhalation route of exposure) are discussed in Section 2.2.1.1. No studies were located regarding death in animals after inhalation exposure to inorganic lead. 

Information on occupational exposure to lead is obtained primarily from the National Occupational Exposure Survey (NOES) and industry surveys of workers. While occupational exposure is widespread, environmental monitoring data on levels of exposure in many occupations are not available. OSHA has established a permissible exposure limit (PEL) for lead of 50 pg/m3 for workplace air (OSHA 1991). NIOSH has estimated that more than 1 million American workers were occupationally exposed to inorganic lead in more than 100 occupations (NIOSH 1977a, 1978a). According to NOES, conducted by NIOSH between 1980 and 1983, an estimated 25,169 employees were exposed to tetraethyl lead (not used in gasoline since December 31, 1995) approximately 57,000 employees were exposed to various lead oxides mostly in non-ferrous foundries, lead smelters, and battery plants 3,902 employees were exposed to lead chloride and 576,579 employees were exposed to some other form of lead in the workplace in 1980 (NIOSH 1990). Workers who operate and maintain solid waste incinerators are also exposed to air lead levels as high as 2,500 pg/m3 (Malkin 1992). 

Balbus-Komfeld JM, Stewart W, Bolla KI, et al. 1995. Cumulative exposure to inorganic lead and neurobehavioural test performance in adults an epidemiological review. Occup Environ Med 52(1) 2-12. 

Fu H, Boffetta P. 1995. Cancer and occupational exposure to inorganic lead compouds A meta-analysis of published data. Occup Environ Med 52(2) 73-81. 

Lindgren KN, Masten VL, Ford DP, et al. 1996. Relation of cumulative exposure to inorganic lead and neuropsychological test performance. Occup Environ Med 53(7) 472-477. 

NIOSH. 1978a. Criteria for a recommended standard Occupational exposure to inorganic lead revised criteria. 1978. Cincinnati, OH U.S. Department of Health. Education, and Welfare, Centers for Disease Control, National Institute for Occupational Safety and Health, 78-158. 

National Institute for Occupational Safety and Health Criteria for a Recommended Standard.. .. Occupational Exposure to Inorganic Lead, DHEW (HSM) Pub No. 73-22020. Washington, DC, US Government Printing Office, 1972... 

Acute exposure to inorganic lead causes renal damage, in particular, damage to the proximal tubules. This is detectable biochemically as amino aciduria and glycosuria. Lead adversely affects reproductive function in both males and females, and recent studies in men occupationally exposed to lead have indicated that testicular function is adversely affected by lead. Animal studies have shown that lead is gametotoxic. Lead is also neurotoxic to the developing nervous system. 

In the environment, inorganic mercury can be methylated by microorganisms to methylmercury. Methyl-mercury will accumulate in the tissues of organisms. The animals at the top of the food chain tend to accumulate the most methylmercury in their bodies. Any source of mercury release to the environment may, therefore, lead to increased levels of methylmercury in tissues of large fish and mammals. Occupational exposures are primarily to metallic mercury vapor. Accidental exposures to mercury are more common than accidental exposures to many hazardous substances, because liquid mercury is shiny and interesting, and because liquid mercury has been used in many electrical and mechanical devices. Accidental exposures, even to small amounts of mercury, may be harmful. Liquid mercury is poorly absorbed by the skin and from the intestines, but vapors that are released from liquid mercury are readily absorbed through the lungs and are very harmful when inhaled. The text in this chapter provides considerable detail on a number of accidental exposures to all forms of mercury. This information is intended to inform the reader and help prevent accidental exposures in the future. 

The earliest American reports of psychiatric symptoms from adult exposures to inorganic lead described symptoms of insanity. With the institution of better working conditions and environmental controls, the frequency of severe poisonings declined in recent decades. Modern studies describe symptoms of depression, other mood complaints, or cognitive decline as primary effects of exposure. One meta-analysis of four studies comparing the risk of Alzheimer s disease from occupational lead exposure found no increased risk (Graves et al. 1991). 

SCOEL, Scientific Committee on Occupational Exposure Limits for Lead (2000). Recommenda-tionfrom Scientific Committee on Occupational Exposure Limits for Lead and its Inorganic Compounds. EU Scientific Committee on Occupational Exposure Limits. 

NIOSH was created in 1970 by the OSHAct and established in the Department of Health Education and Welfare, which became the Department of Health and Human Services, to carry out the duties of the OSHAct assigned to the secretary of health and httman services. Those duties include research, experiments, and demonstrations related to occupational safety and health (Ptrblic Law 91-596). NIOSH first published its Criteria for a Recommended Standard Occupational Exposure to Inorganic Lead in 1973. After an OSHA proposal to revise the occupational health standard for inorganic lead in 1976, NIOSH revised its criteria document in 1978 and lowered its recommended 10-hotrr TWA for airborne lead from 150 to 100 pg/m and its recommended maximum BLL from 80 to 60 pg/dL (NIOSH 1978). 

Osterberg, K., J. Boijesson, L. Gerhardsson, A. Schtltz, and S. Skerfving. 1997. A neurobehavioral study of long-term occupational inorganic lead exposure. Sci. Total Environ. 201(1) 39-51. 

Are employees at risk of exposure to inorganic arsenic, lead, cadmium or cadmium compounds, benzene, coke-oven emissions, occupational exposure to blood or other potentially infectious materials, or cotton dust ... 

Under this interim final standard occupational exposure to inorganic lead is to be limited to 50 pg/m (micrograms per cubic meter) based on an 8 hour time-weighted average (TWA). This permissible exposure limit (PEL) must be achieved through a combination of engineering, work practice and administrative controls to the extent feasible. Where these controls are in place but are found not to reduce employee exposures to or below the PEL, they must be used nonetheless, and supplemented with respirators to meet the 50 pg/m exposure limit. 

This document outlines the medical monitoring program as defined by the occupational safety and health standard for inorganic lead. It reviews the adverse health effects of lead poisoning and describes the important elements of the history and physical examinations as they relate to these adverse effects. Finally, the appropriate laboratory testing for evaluating lead exposure and toxicity is presented. 

Arvidson B (1992) Inorganic mercury is transported from muscular nerve terminals to spinal and brainstem motoneurons. Muscle Nerve 15 1089-1094 Balestra DJ (1991) Adult chronic lead intoxication. Arch Intern Med 151 1718-1720 Barregard L, Sallsten G, Schiitz A, Attewell R, Skerfving S, Jarvholm B (1992) Kinetics of mercury in blood and urine after brief occupational exposure. Arch Environ Health 47 176-184... 

---