Pulmonary hypersensitivity in the alginate industry.

Salts of alginic acid are complex polymerised polysaccharides which are chemically extracted from seaweed. Workers in the alginate industry are exposed to dust from dried milled seaweed and pure alginate compounds. In this survey of one of the two factories in Britain producing alginates, we found evidence of pulmonary hypersensitivity to seaweed dust in seven per cent of the total work force, and evidence of precipitating antibody to sodium alginate and seaweed extracts in the serum of 4.5 per cent of the work force. Challenge testing of a number of employees with symptoms showed a dual response with immediate airways obstruction, and a later loss of lung volume, with associated impairment of transfer factor.