(GALLE - A geomedical approach to a coastal town in Sri Lanka (Ceylon)

The essence of the book is an approach to the spa­ tial distribution of health and disease. This geomedical approach consists in the description of areas within the town of Galle, homogeneous wjith respect to the ecological factors, which de­ termine the quality of life and the health of their inhabitants. The author names these areas "hygiochores" in accordance with nosochores, areas of uniform prevalence of diseases. The hygiochores do not correspond with the admin­ istrative areas in Galle. One of the basic problems in geomedical analysis is the fact that statistical data are available only for administrative areas, which are not necessarily identical with ecological units. Rivers, hills, or streets are often depicted as ad­ ministrative boundaries, whereas from an ecologi­ cal point of view they are the central structures. It was nevertheless possible to use the original cen­ sus of 1981, since census blocks are very small. Most of the other data the author collected her­ self by way of household-interviews, inspection of all rooms and facilities in 300 households (1958 inhabitants), stool samples of children 3 12 years old, interviews with hospital in-patients, and mapping of such relevant factors as vegeta­ tion (Figure 1), run-off, soil, private water supply (Figure 2), public water supply quality of streets, public and private buildings (Figure 3), toilets (public and private and open land, sea-shore), (Figure 4), ethnic groups (Figure 5).

This book was originally written as a thesis which had been initiated 'by Professor U. Schweinfurth. Field work was carried out in Sri Lanka from Sep tember 1981to September 1982, and again in March 1983 The essence of the book is an approach to the spa tial distribution of health and disease. This geomedical approach consists in the description of areas within the town of Galle, homogeneous wjith respect to the ecological factors, which de termine the quality of life and the health of their inhabitants. The author names these areas "hygiochores" -in accordance with nosochores, areas of uniform prevalence of diseases. The hygiochores do not correspond with the admin istrative areas in Galle. One of the basic problems in geomedical analysis is the fact that statistical data are available only for administrative areas, which are not necessarily identical with ecological units. Rivers, hills, or streets are often depicted as ad ministrative boundaries, whereas from an ecologi cal point of view they are the central structures. It was nevertheless possible to use the original cen sus of 1981, since census blocks are very small. Most of the other data the author collected her self by way of household-interviews, inspection of all rooms and facilities in 300 households (1958 inhabitants), stool samples of children 3 -12 years old, interviews with hospital in-patients, and mapping of such relevant factors as vegeta tion (Figure 1), run-off, soil, private water supply (Figure 2), public water supply quality of streets, public and private buildings ( Part One gives an introduction to the physical geography of the town of Galle ( Figure 6). Two parallel hill ranges, running NE-SE and end ing on the peninsula, where the Fort was built in colonial times, are the most prominent features. They form the western rim of a geological depres sion, which has a sandy coastal plain -the north ern shore of a natural harbour -at its centre. This densely inhabited coastal plain with high water table is one of Galle's problem areas. But most of the health hazards prevail in the low-lying streches of the little rivers running parallel to the hills, especially of the Moragoda Ela at the centre of the depression.
The geographical introduction is followed by an account of Galle's history and by cultural regionalisation of the town. The densely inhab ited areas and the Central Business District (CBD) are oriented towards the harbour, whereas the outer parts of the town are determined by the ar terial roads, which follow orography (Figure 7). The upper class prefers the hill ranges as residen tial areas, the lowest class is displaced to the lowlying areas. It can be demonstrated that type of housing indicates the socio-economic status of the inhabitants.
Part One ends with a description of the main fac tors of urban landscape as far as they are relevant to the following geomedical analysis. Water sup ply and water disposal are outstanding problems in a tropical environment. While a dense network of pipes guarantees that water supply is sufficient, no sewage system exists except for a drainage system for storm water in the Fort. The water runs in open canals. The toilets are connected to pits or septic tanks. All sewage water whatever the means of its disposal, bears health risks as breed ing place of mosquitoes or distributor of wormdiseases.
The drainage system in the Fort (p. 224 ff) is of special historical interest. Due to lack of mainte nance it has today turned into a health hazard. Maintenance was prevented by a commonly held belief that the drainage system was washed by the tide. The author was able to defeat this disastrous assumption and to show that the canals are partly blocked, and inhabited by rats and insects.
Part Two relates the findings of the survey to regionalisation. Housing, education, age structure, income, and diseases are analysed in context with the environment. Filariasis and geohelminthic diseases are the two main topics of this chapter. Galle is situated within the "filarial belt" of Southern Sri Lanka (A. S. Dissanayake, 1965, 1984: U. Schweinfurth, 1983. By mapping all microfilaria-positive cases as reported by the Anti-Filariasis Control Unit of Galle, 1971-1979, the coastal plain was identified as the most heavily infested area. Two characteristics are prominent: high population density and low num ber of registered breeding places. Three factors are likely to be responsible for the high number of microfilaria positives: 1.
proximity of the Moragoda Ela: centre of the depression; high water table.
2. high population density: discarded recep tacles as breeding places for mosquito vec tor; high number of microfilaria positives as reservoir.
3. insufficent control measures, as discarded receptacles cannot be sprayed.
In Sri Lanka geohelminths are very common para sites in humans. Stools of428 children (3 -12 years) were investigated for Trichuris trichiura, Ascaris lumbricoides, and Hookworm. 206 (= 48%) con tained more than one species. Again the low-ly ing areas are the most affected ( Figure 9). Due to habitat conditions characterized by humid but well aerated soils, prevalence of hookworm is highest in the low-lying areas (Figure 10), espe cially when there are defaecation grounds in the open as a result of a lack of toilet facilities. Due to the high water table, pits cannot be built in these areas, and septic tanks are too expensive for the mostly poor families. Ascaris lumbricoides is con nected to high housing density, especially when more than 6 households share one toilet fFigure 11). Trichuris trichiura is found all over the town (73% of the children investigated). Only children of rich families with high education and high living stan dard are free of it, irrespective of the environment they live in. Figure 12 gives a synopsis of prevalence zones for worms:

The Ceylon Journal of Medical Science
I. The Fort is free of hookworm (tarred streets, sufficient toilets); Ascaris and Trichuris are rare. II. Densely built areas without trees (i.e. shadow): prevalence of the three worms is about average. HI. Coastal plain and low-lying areas: highest prevalence. TV. Sparely populated areas and hills: preva lence below average. i The hygiochores appear as a synopsis of the fac tors analysed. For purely practical reasons it is not possible to consider all ecological factors rel evant to health. The author therefore has to be content to describe the hygiochores according to the factors which she analysed during the sur vey: natural regions, vegetation, utilization in his tory, population density, public buildings and in dustries, house-types and socio-economic status, sanitary facilities, ethnicity, infrastructure, sup ply with goods of daily demand, access to medi cal facilities, selection of diseases.
Six types of hygiochores (A-F) have been identi fied ( Figure 13): 'A' indicates areas where qual ity of life is best and the incidence of diseases low est. 'F' indicates areas most unfavourable to health and quality of life. In the cultural regionalisation, zones are arranged in half-circles with the harbour in their centre. When the ecological setting and the values defining living and health conditions are taken into account, the half-circles become pen etrated by a more sectoral or striped pattern, shaped in accordance with the parallel cpnfiguartion of hill ranges and valleys (hygiochores A and F), i.e. with topography.
There are two problem areas in town: on the one hand the low-lying areas, where hehninthic dis eases are prevalent and where lack of infrastruc ture and temporary flooding cause inconvenience; on the other hand the slum areas in the inner ur ban core, with high density of housing, with a high rate of poverty and unclean conditions. In both cases, the inhabitants have a low educational standard and live in an unhealthy environment. On the upper end of the social ladder -and in glar ing contrast to the above-mentioned -the upper class and upper middle class live in the areas of best quality of life in Galle, designated with the hygiochore 'A'. They dwell in spacious villas with servants and sanitary facilities and enjoy the con veniences of a good infrastructure. Infectious dis eases and undernutrition are rare.
Despite such differences regarding education, standard of living, hygiene, and nutrition, differ ences in health status are distinct but not dramatic. The described hygiochores differ in this respect less than one should expect. To account for this, three characteristics of the town of Galle must be considered: 1. Favourable geographical conditions: high rainfall, i.e. sufficient water supply, proxim ity to the Indian Ocean, lateritic soil and hilly landscape in most parts of the town, remote ness from the flood endangered catchment area of the Gin Ganga river, and a climate enabling the inhabitants to stay in the open all-day.
2. Traditions: daily body-wash, boiling of all meat, fish and vegetable, the idea of preven tive measures in Ayurvedic medicine.
3. Since Galle is a place of out-migration, it is unaffected by the consequences of invasion by impoverished crowds from the rural ar eas. The few slum-areas in the town-centre are infinitely better than the slums in Co lombo, which are situated in the low-lying areas, i.e. the most difficult invironment. The low-lying areas of Galle are also inhabited by urban poor, but the term 'slum' would be inappropriate for the widely scattered huts located on grassy land beneath coconut-trees and built of traditional material, where they live.  On the basis of hygiene as a "science of maintaining health", areas of identical importance for health are termed "hygiochores".

Acknowledgements
The author thanks several persons for assistance given, first among them being Ms Sita Wijenayake who introduced her to local politicians which helped to smoothen her progress. She also thanks all administrators -State and District officials, the Census Department, the Geology Department, Survey Department, the Health Ministry and Ports Authority. A special word of thanks to the anti-filariasis and anti-malarial units of the Health Ministry. She remembers with gratitude the co operation extended to her by members of all the households visited and studied by her. She thanks the Dean, Faculty of Medicine, University of Ruhuna for advice, encouragement and support.