OCCUPATIONS, WAGES AND LABOUR ORGANIZATION
47
Silicosis is the most serious occupational disease found in Hong Kong, though fortunately the number of cases on record is only twenty nine. The disease occurs among workers in quarries where granite of a high silica content is produced and also in factories where quartz is ground for industrial use. The proportion of workers in the latter trade who have been affected is high and the time of development of the disease unusually short. Lead poisoning occurs in small factories where scrap materials are smelted to recover the lead and in which the maintenance of healthy conditions is difficult. Dermatitis occurs in a wide range of industries, but probably the most important single cause is the use of solvents, such as kerosene, to clean-the hands after work. Aniline poisoning has again been met with among wharf coolies handling-leaking containers, and cases of hydrogen sulphide gas- sing occurred in coolies at a refuse dump.
Trades known to be hazardous to workers have been surveyed during the year; individual factories are kept under observation and workers in them medically examined. All workers in stone- grinding factories have been X-rayed; blood examinations have been carried out on lead workers and those handling radio-active substances, while the latter also wear film badges which are examined by the Radiological Protection Service of the Medical Research Council.
The number of examinations carried out during the year was as follows:
Film badges:
11
Spoilt
2
Excessive dose
11
Excessive and Contaminated
4
Contaminated
25
Normal
132
174
Blood Counts on:
Lead workers
Luminisers
19
26
12
Urine samples for lead content
When cases of disease due to the patient's occupation are found, the circumstances are investigated and recommendations made in