Short term effects
Metal fume fever
Metal fume fever occurs in welders who inhale zinc oxide fumes, although other components, for example, copper, aluminium and magnesium, may also produce this condition. Symptoms of metal fume fever, which resemble influenza, usually occur several hours after exposure and include a metallic or sweet taste, chills, thirst, fever, muscle aches, chest soreness, fatigue, gastro- intestinal pain, headache, nausea and vomiting. The symptoms usually subside within one to three days of exposure with no residual effect.
Exposure to ozone
Exposure to ozone generated in GMAW and plasma arc welding may produce excessive mucus secretion, headache, lethargy, eye irritation and irritation and inflammation of the respiratory tract. In extreme cases, excess fluid and even haemorrhage may occur in the lungs. The irritant effects of the gas on the upper respiratory tract and the lungs may be delayed.
Exposure to nitrogen oxides
Nitrogen oxides produce somewhat similar respiratory tract effects to ozone. Inhalation of nitrogen oxides does not always produce immediate irritant effects but may result in excessive fluid in the lung tissues (pulmonary oedema) some hours after exposure ceases.
Long term effects
Details of long term health effects specific to individual welding fume and gas components are given in Appendix 4.
Respiratory system
On the basis of studies which have been undertaken, there is evidence that chronic obstructive diseases are made worse by smoking.
Nervous system
Out of the possible welding fume components, lead and manganese are toxic to the nervous system (see Appendix 4).
Cardiovascular system
Carbon monoxide, generated in carbon dioxide-shielded GMAW processes, combines readily withhaemoglobin, thereby lowering the oxygen-carrying capacity of blood. For this reason, exposure to carbon monoxide may present an added health risk to welders with heart disease.
Skin
Chromium (VI) compounds, which may occur in stainless steel or related welding fumes, are a frequent cause of dermatitis (see Appendix 4).
Carcinogenic effects
There is concern regarding the presence of potential cancer causing agents, carcinogens, in certain types of welding fumes and gases. In this context:
? the particulate form of fume may be carcinogenic, but no definitive human or animal
study results are available;
? chromium (VI) and nickel (see Appendix 4) are implicated in respiratory tract cancer in other, non-welding, industrial settings;
? ozone is a suspect lung carcinogen in laboratory animals, but no studies of the long term effects of ozone on exposed welding populations have been documented; and
? the welding arc emits ultraviolet radiation of wavelengths that have the potential to produce skin tumours in animals and in over-exposed individuals, however, no confirmatory studies of this effect in welders have been reported. Lung cancer is the most common form of human cancer. Studies of lung cancer among welders indicate that they may experience a 30 to 40 per cent increased risk compared to the general population. Since smoking or exposure to other cancer-causing agents, such as asbestos fibres, may have influenced the results, it is not known whether welding represents a significant lung cancer risk. It is considered that welding done on mild steel represents little risk. Stainless steel welders are exposed to chromium and nickel and may be a high risk group, which might account
for the overall increase in lung cancer incidence among welders.
Taken from Here:
http://www.nohsc.gov.au/PDF/Standards/WeldingFumesGases.pdf
