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An assessment of metal recycling worker lead exposure associated with cutting uncoated new steel scrap.
Zhu J; Depersis R; Pavelchak N; London M; Gibson AM; Franko E
J Occup Environ Hyg 2009 May; 6(5):D18-D21
Scrap metal can generally be categorized as new or old. Junked cars and demolished bridge beams are examples of old scrap; new scrap is generated during product manufacturing processes. For example, when steel mills fabricate stock into bars, rods, plates, or sheets, new steel scrap is generated as cuttings, trimmings, and off-specification materials. Additional new scrap is generated as the material moves through a series of manufacturing and finishing processes to become a final product. New and old steel scrap is usually recycled separately at metal recycling facilities because it is sold at different prices and may go to different smelting facilities. At a metal recycling facility, large and bulky scrap materials are often cut into smaller pieces for ease of handling or volume reduction. The torch cutting operation is performed by a worker, often referred to as a burner or a cutter, who uses either an oxygen-propane or oxygen-acetylene cutting torch. The metal is generally heated between 1400 to 1600.F (760.870.C) in the presence of oxygen. The intense heat generates large quantities of metal fumes and fine dust particles, including lead oxide. Lead, a well-known environmental and industrial toxicant, is classified as a confirmed animal carcinogen by the ACGIH, and the International Agency for Research on Cancer (IARC) categorizes lead as a probable human carcinogen. Once lead gets into the body, it travels in the blood to the soft tissues, such as the liver, kidneys, lungs, brain, spleen, muscles, and heart before it moves to the bones and teeth where it may stay for decades. Elevated blood lead levels in adults can damage the cardiovascular, central nervous, reproductive, hematologic, and renal systems. The Occupational Safety and Health Administration (OSHA) has established a permissible exposure limit (PEL) of 50 micrograms of lead per cubic meter of air (ug/m3) as a time-weighted average (TWA) over an 8-hr workday. The potential lead hazards associated with cutting old scrap materials have been studied and documented. Old scrap materials may contain lead from a number of sources; the metal may be painted with lead-based paint or soldered with lead solder. Some scrap metals may have zinc-galvanized coatings that contain lead as an impurity. A worker performing burning can inhale or ingest lead fumes and dust, potentially resulting in irreversible adverse health effects. New steel scrap typically does not have painted or galvanized coatings and is free of visible surface contaminants. According to a survey conducted by the New York State Department of Health (http://www.health.state.ny.us/environmental/workplace/metal_recycling/metal_recycling_report.htm), many metal recycling companies assume that uncoated new steel scrap is lead free, and thus, they do not provide respiratory protection for workers who cut uncoated new steel scrap.
Epidemiology; Exposure-levels; Lead-compounds; Statistical-analysis; Humans; Men; Women; Blood-tests; Metals; Risk-analysis; Fumes; Metal-fumes; Metal-compounds; Metallic-compounds; Metallic-fumes; Particulate-dust; Particulates; Dust-exposure; Dust-inhalation; Dust-particles; Dusts; Toxic-effects; Carcinogens; Hazards; Respiratory-irritants; Pulmonary-function; Pulmonary-system; Pulmonary-system-disorders; Pulmonary-cancer
Issue of Publication
Journal of Occupational and Environmental Hygiene
New York State Department of Health/Health Research Incorporated
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division