M-28
1. Water Supplies.-The water supplies of Hong Kong and Kowloon are in charge of the Water Works Branch of the Public Works Department.
2. All the water is surface water collected from catchment areas which are free from ordinary risks of pollution.
3. The water, after storage for a longer or shorter period in the impounding reservoirs, is filtered, in some cases by the slow sand system in others by the rapid system and finally chlorinated.
4. Routine examinations are carried out by the Government Bacteriologist and Government Analyst and the results furnished to the Water Authority. There was no evidence of any disease having been conveyed through the public water supplies.
1. Clearance of Bush and Undergrowth.-Generally speaking, in Hong Kong and the New Territory, bush and undergrowth is little in evidence except in those places where it has been planted and conserved. Routine cutting of superfluous undergrowth is carried out in May and October.
2. In Hong Kong, as in many other parts of the world, there appears to be a general belief that the cutting of undergrowth and the clearance of bush in some way brings about a diminution in the number of mosquitoes especially the species which carry malaria. Whatever may be the effect on culicines it is a fact that the very potent malaria carriers-Anopheles Maculatus and Anopheles Minimus breed in water open to the light and shun that shaded by trees or undergrowth. Clearance of bush may, therefore, result in an increase of malaria rather than in a diminution.
1. Sanitary Inspectors.-During the year the Sanitary Inspectors continued their routine visits of inspection. Under their supervision 96,875 floors were cleansed in Hong Kong and 55,710 in Kowloon. This means that practically all premises were cleansed twice during the year. Lime washing was done on 44,849 floors.
## SCHOOL HYGIENE
1. The School Inspection Branch of the Medical Department consists of one Lady Medical Officer and one Nurse. These Officers work in close touch with the Education Department.
2. The following information is taken from the Annual Report of the School Medical Officer.