Welding joins pieces of metal by the use of heat, pressure, or both, making it one of the most dangerous industrial occupations. Welding workers are constantly exposed to fire, electric shock, compressed gases, and toxic fumes. Welding requires an enormous degree of precautionary measures due to the extreme risk of personal injury from even minor accidents. Fumes are a natural by-product of welding, and the toxic fumes produced by welding include carbon monoxide and nitrogen oxide. Metal-fume fever is a condition that results from welding metal coated with, or containing: zinc, cadmium, chromium, copper, fluoride, lead, manganese, or vanadium.
Dangerous fumes that are released during welding operations are derived from the following:
Base material being welded or the filler material that is used
Coatings and paints on the metal being welded, or coatings converting the electrode
Shielding gases supplied from cylinders
Chemical reactions resulting from the action of ultraviolet light
from the arc and heat
Process and consumables used
Contaminants in the air, for example vapors from cleaners and degreasers
Exposure to welding smoke can cause lung, heart, kidney, and central nervous system problems.
Exposure to the fumes affects the central nervous system and can cause disorders of the central nervous system and neurological problems. “Manganism“, or manganese poisoning, is often the result of exposure to welding fumes. Manganism is characterized by mental difficulties and the impairment of motor skills. The materials used to join the metal are commonly referred to as welding rods. Other materials may be used, however the welding rods normally contain a higher percentage of manganese. Most rods, wires and electrodes contain manganese, which is a toxic element that passes quickly into the blood stream and tissues of the body. Most often the element enters its victim through the lungs.
Symptoms of Manganism include:
- Awkward gait
- Abnormal balance
- Memory loss
- Impairment of motor skills
- Slurred speech
- Lack of facial expression
- Sleep disorders