Clinical studies in workers engaged in maintenance of watermark moulds in a paper mill.

Thirty subjects engaged in maintenance and repair of moulds used for producing watermarks on paper were studied, along with 27 control subjects from the same paper mill. The workers were simultaneously exposed to copper, chromium, zinc, xylol, and fumes of sulphuric acid in the course of their work. The study subjects were investigated for clinical, occupational, radiological haematological and psychological details. The aforementioned combined exposure was found to be responsible for a high prevalence of symptoms pertaining to the respiratory system and higher nervous functions. Breathlessness (26.7%), expectoration (10.0%) and emphysema (10.0%) were significantly higher among the exposed subjects. The exposed subjects also showed lowered visuomotor coordination and delayed reaction to light and sound stimuli.