Welding, particularly the “smoke” (i.e., fumes and gases) produced during welding operations, presents many health hazards. Welding smoke is a mixture of very fine particles (fumes) and gases. Many of the substances in welding smoke, such as chromium, nickel, arsenic, asbestos, manganese, silica, beryllium, cadmium, nitrogen oxides, phosgene, acrolein, fluorine compounds, carbon monoxide, cobalt, copper, lead, ozone, selenium, and zinc, can be extremely toxic. Welding smoke can be generated from sources, such as the base material being welded or the filler material that is used, the coatings and paints on the metal being welded, and chemical reactions that result by the action of ultraviolet light from the arc and from heat. The individual components of welding smoke can affect just about any part of the body, including the lungs, heart, kidneys, and central nervous system.
The following provides general information on the health hazards of welding smoke.
Short-Term (Acute) Health Effects Created by Welding Smoke
Exposure to metal fumes, such as zinc, magnesium, copper, and copper oxide, can cause metal-fume fever. Symptoms of metal-fume fever may occur 4 to 12 hours after exposure, and include chills, thirst, fever, muscle ache, chest soreness, coughing, wheezing, fatigue, nausea, and a metallic taste in the mouth.
Welding smoke can also irritate the eyes, nose, chest, and respiratory tract, and cause coughing, wheezing, shortness of breath, bronchitis, pulmonary edema (fluid in the lungs) and pneumonitis (inflammation of the lungs). Gastrointestinal effects, such as nausea, loss of appetite, vomiting, cramps, and slow digestion, have also been associated with welding smoke.
Some components of welding fume (e.g., cadmium) can be fatal in the short term. Ultraviolet radiation given off by welding reacts with oxygen and nitrogen in the air to form ozone and nitrogen oxides. These gases can be fatal at high doses, and lower doses can cause irritation of the nose and throat and serious lung disease. Ultraviolet rays given off by welding can react with chlorinated hydrocarbon solvents, such as trichloroethylene, 1,1,1-trichloroethane, methylene chloride, and perchloroethylene, to form phosgene gas. Exposure to even a very small amount of phosgene may be fatal. The early symptoms of exposure usually take 5 or 6 hours to appear and include dizziness, chills, and coughing.
Long-Term (Chronic) Health Effects Created by Welding Smoke
Studies of welders have shown that they have an increased risk of lung cancer, and possibly cancer of the larynx (voice box) and urinary tract. Welders may also experience a variety of chronic respiratory (lung) problems, including bronchitis, asthma, pneumonia, emphysema, pneumoconiosis (refers to dust-related diseases), decreased lung capacity, silicosis (caused by silica exposure), and siderosis (a dust-related disease caused by iron oxide dust in the lungs).
Other health problems that appear to be related to welding include heart disease, skin diseases, hearing loss, chronic gastritis (inflammation of the stomach), gastroduodenitis (inflammation of the stomach and small intestine), and ulcers of the stomach and small intestine. Welders exposed to heavy metals, such as chromium and nickel, have also experienced kidney damage.
Welding also poses reproductive risks to welders. Studies have found that welders, and especially welders who have worked with stainless steel, had poorer sperm quality than men in other types of work. Several studies have shown an increase in either miscarriages or delayed conception among welders or their spouses. Possible causes include exposure to metals, such as aluminum, chromium, nickel, cadmium, iron, manganese, and copper; gases, such as nitrous gases and ozone; heat; and ionizing radiation that is used to check the welding seams.
Welders who perform welding or cutting on surfaces covered with asbestos insulation are at risk of asbestosis, lung cancer, mesothelioma, and other asbestos-related diseases.
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