Pulmonary responses to welding fumes: role of metal constituents.
It is estimated that more than 1 million workers worldwide perform some type of welding as part of their work duties. Epidemiology studies have shown that a large number of welders experience some type of respiratory illness. Respiratory effects seen in full-time welders have included bronchitis, siderosis, asthma, and a possible increase in the incidence of lung cancer. Pulmonary infections are increased in terms of severity, duration, and frequency among welders. Inhalation exposure to welding fumes may vary due to differences in the materials used and methods employed. The chemical properties of welding fumes can be quite complex. Most welding materials are alloy mixtures of metals characterized by different steels that may contain iron, manganese, chromium, and nickel. Animal studies have indicated that the presence and combination of different metal constituents is an important determinant in the potential pneumotoxic responses associated with welding fumes. Animal models have demonstrated that stainless steel (SS) welding fumes, which contain significant levels of nickel and chromium, induce more lung injury and inflammation, and are retained in the lungs longer than mild steel (MS) welding fumes, which contain mostly iron. In addition, SS fumes generated from welding processes using fluxes to protect the resulting weld contain elevated levels of soluble metals, which may affect respiratory health. Recent animal studies have indicated that the lung injury and inflammation induced by SS welding fumes that contain water-soluble metals are dependent on both the soluble and insoluble fractions of the fume. This article reviews the role that metals play in the pulmonary effects associated with welding fume exposure in workers and laboratory animals.
Antonini
James M
JM
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA. jga6@cdc.gov
Taylor
Michael D
MD
Zimmer
Anthony T
AT
Roberts
Jenny R
JR
D000395:Air Pollutants, Occupational / Q000506:poisoning*; D000497:Alloys / Q000737:chemistry / Q000506:poisoning; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004195:Disease Models, Animal; D014943:Global Health; D006801:Humans; D015994:Incidence; D007249:Inflammation; D019570:Inhalation Exposure / Q000009:adverse effects*; D008171:Lung Diseases / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology; D008452:Maximum Allowable Concentration; D008670:Metals / Q000737:chemistry / Q000506:poisoning*; D009314:National Institute for Occupational Safety and Health, U.S.; D016273:Occupational Exposure / Q000009:adverse effects*; D010316:Particle Size; D012995:Solubility; D014481:United States / Q000453:epidemiology; D014896:Welding / Q000295:instrumentation / Q000379:methods
D000395:Air Pollutants, Occupational; D000497:Alloys; D008670:Metals