Abstract
A health hazard may arise in the manufacture and use of certain metal powders. Lead is readily absorbed from the lungs and can become a general poison in the body. Cadmium inhaled from metal spraying may also lead to toxic effects. Certain metals may produce allergic effects. Cobalt can produce an acute asthma in sensitive individuals and a slowly developing fibrosis of the lungs that has occurred in tungsten carbide workers is almost certainly due to cobalt. Aluminium powders as used for fireworks have caused very acute and severe fibrosis of the lungs. Some metals such as tin and iron are deposited in the lungs where they are innocuous but produce marked shadows in radiographs of the chest. The prevention of ill effects requires a knowledge of the possible hazards and the avoidance of levels in the atmosphere above the accepted threshold limit values. In certain circumstances medical supervision is desirable.