H.—3l.

With the exception of Korokoro School, all the schools are situated on the river-flat, and the water-supply is either deep artesian or shallow well, with the exception of Upper Hutt and Korokoro, which have upland surface-water supply. Petone schools are partly Korokoro water-supply and partly deep artesian. In the following table the schools are grouped according to their water-supply and the percentage of goitre for each group given. Percentage of Goitre. A. Upland surface-water supply .. .. .. .. 21-7 B. Artesian water-supply .. .. . . .. .. 27-3 C. Shallow-well water-supply .. .. .. .. 21-8 The Petone figures are not included in the above table, as Petone water-supply is partly artesian and partly upland surface, and it is impossible to differentiate between the two supplies. The average percentage of goitre in Petone school-children is 45-6. It should be noted that the figures of group C are small compared with groups A and B. As a comparison, the figures for four Wellington City schools are given below. The water supplied here is from entirely upland surface : Total number of children examined, 1,891 ; percentage of goitre, 21-9 —a percentage that corresponds closely with group Ain the previous table. It would appear therefore, that the percentage of goitre from those areas supplied by artesian water shows a distinct increase over the percentage obtained from districts supplied with upland surface water. Goitre Incidence in relation to Length of Residence in the District. Percentage Length of Residence. of Goitre. Under one year .. .. .. . . .. . . 22-6 Over one year and under two years .. .. ~ .. 324 Over two years and under three years .. .. 21-4 Over three years 'and under five years .. .. .. 25-5 Over five years and under ten years .. .. .. .. 33-0 Over ten years .. .. . . .. .. .. 33-6 In seeking the information, unless a child was very definite in answering, the answer was neglected, and as an extra safeguard the replies obtained only from children who were nine years or over were analysed. So far not a big number (612) of replies have been tabulated, so that when larger numbers are used the percentage obtained may be altered. Of the figures so far available, there seems to be a definite increase in the incidence of goitre according to length of residence. Classifying the register into two groups, with five years' residence as the boundary, we get : Under five years' residence, percentage of goitre, 25-8 ; over five years' residence, 33-2—a difference that even on the numbers available would appear to be significant. Incidence of Goitre in Yearly Age Groups.—The following table gives the incidence of goitre in each yearly age group for the district. The second column is the percentage of both sexes combined, the third is for males, and the fourth for females.

" Age group " indicates that the child, say, ten-years-age group was ten years old last birthday. The figures in the fifteen- and sixteen-years group are too small for the percentages to have any significance. Very few of this age were found at primary schools, and only two secondary schools have so far been examined. The trend of these figures is better illustrated in the accompanying group. Chemical investigation of the water and soils in this area of this investigation is at present being carried out, but results are not yet available.

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Goitre Percentage. Goitre Percentage. Age Group. Age Group. Sexes. Males. Females. Males. Females. 5 years .. .. 24-9 34-2 17-3 11 years .. 39-3 35-6 43-2 6 ,, .. 25-3 27-7 23-4 12 „ .. 40-3 37-9 42-9 7 „ .. 24-8 25-9 23-7 13 „ .. 46-2 41-5 49-2 8 ,, .. 25-8 26-4 25-4 14 „ .. 33-7 27-5 40-3 9 „ .. 31-1 29-8 32-4 15 „ .. 28-4 26-2 30-6 10 „ .. .. 34-6 36-2 32-9 16 „ .. 40-0 27-8 52-9