Occupational Medicine 1987;37:62-65
© 1987 Society of Occupational Medicine
research-article |
Silica Hazard of Caisson Construction in Hong Kong
Occupational Health Division, Labour Department Hong Kong
Caisson construction work in Hong Kong generates considerable silica dust from granite rock. A survey of 18 sites was aimed at assessing the hazard of silica dust and determining the prevalence of silicosis among caisson workers. Data from 87 air samples confirmed high silica exposure in general with a severe exposure hazard for underground workers drilling rocks under conditions of little or no wet suppression. Of 118 workers radiologically examined, 12 cases of silicosis (including 6 cases of silico-tuberculosis) were found in underground workers (giving an overall prevalence of 16 per cent in this group), and only in those with 10 to 20 years of work experience. The occurrence of tuberculosis in another 6 underground and 2 surface workers appeared to be higher than expected. The findings confirmed a serious occupational health hazard and the need for preventive action.
Requests for reprints should be addressed to: T. P. Ng, Occupational Health Division, Labour Department, Hong Kong.