Koster Health

by Professor Guy Heyden, UNESCO - Cousteau Ecotechnie Chairholder, GOTEBORG UNIVERSITY

The Koster Islands are the westernmost inhabited islands of Sweden, located in the Skagerrak, close to the Norwegian border, some 10 km west of the mainland town of Stromstad. The islands have had a permanent population since the fourteenth century. By tradition, the islanders demonstrate very little geographic mobility, which makes it possible to study several generations of the same family from Koster. No specific genetic disorders exist. Population growth is positive and young people prefer to go on living on the islands. The main industries are fishing and the tourist trade.

There are very few cars on Koster, the commonest means of transportation being motorbike and bicycle. This makes for very little motor traffic. Moreover, the area has no polluting industries. Thus, the Koster islands provide a unique possibility for studying changes in the background environment of western Sweden. The islands are also ideal for detailed follow-up of what impact a local population can have on the immediate environment and what impact environmental changes may have on the well being of the human individuals

The population living year-round on the islands of North and South Koster totals 350. The summer population may exceed 4000. Tourism is greatest when there is least rain. This places a tremendous strain on the water and waste water system on the islands which, in turn, poses a threat to drinking water, the most important human foodstuff. The islanders have been aware of these problems for many years.


This project was initiated in 1987 as a follow-up study of the human living conditions and ageing in a changing environment. However, during the first year of the study it was evident that the islanders were more concerned about changes in their immediate environment than about their physical health. This concern motivated a broadening of the scientific approach to include also detailed monitoring of environmental changes - from the ozone layer to the ground water (“vertical dimension”) and from the social network into the oral health (“horizontal dimension”).

Since 1989, more than 15 research areas at Goteborg University are represented in the project, along with scientists from Chalmers University of Technology. The aim of the project is to study the nature of “islandness”, the living conditions and the well being of roughly 180 adult Koster inhabitants and to develop and evaluate methods to assist each participating islander in taking greater self-responsibility for his or her local environment and health, if they so choose.

The impact of environmental changes on human quality of life is followed up by means of annual in-depth interviews concerning personal social psychological, nutritional, general medical, oral medical, and neighbouring environmental conditions, supplemented by simple health investigations. From 1996, an international health survey was included in the project with a focus on human quality of life. Each participating islander is his or her own control through the years. Thus, the scientific design of the project has a “bottom-up” approach with a focus on intra-individual comparisons.

Ongoing variations in the “health” of the neighbouring environment on Koster are documented by longitudinal recordings of meteorological parameters, solar (including UVB) radiation, air and rain pollution, water quality changes, and plant life alterations.

In conclusion, the Koster Health project has been developed into an educational model with a comprehensive view of the human condition and with a focus on human quality of life in a changing environment.


By way of introduction it should be stressed that the problems described below are not worse on Koster than in any other place. They are, on the contrary, less dramatic there than in many other areas subjected to environmental threats. The islands have a favourable geographical location and an ecologically alert and engaged population striving to preserve the natural and cultural resources for coming generations. Therefore, Koster remains as representative of some of the most “virgin” islands of Sweden and an attractive resort area, especially for people interested in folklore and natural beauty.

The investigations performed in the Koster Health project are comprehensive and detailed. The closer the examinations - the more threats against human well being may be detected. The results may therefore give the uncritical observer a false negative impression of the island condition. However, the studies may favour comparatively early “health” - promoting interventions. By avoiding sweeping the existing problems under the carpet and keeping islanders and visitors well informed about the environmental threats and possibilities of protective measures the islands may be regarded as “safe” and especially attractive.

Here follow some results in summary:

  • Koster is exposed to pollution from both industries and motor traffic - despite the fact that there are no such local sources of pollution on the islands. The islands are subjected to industrial effluents from elsewhere in Europe and to environmental threats from the open sea, including vessel traffic and oil rigs in the North Sea. Slowly, but clearly, pollution is having an impact on the flora and fauna of the islands. Acid rain in combination with airborne sea salts (an effect of climate change?) is impoverishing the soil and threatening the unique flora of Koster. The plant life is adapting itself to the environmental changes.

  • The chloride level in the Koster drinking water is continuously on the rise. An increased salinity and acidity in well water is favouring corrosion of the household water supply pipes and release of metals in the drinking water. Such changes may contribute to, among others, stomach disorders in sensitive individuals and people with generally poor health. Long-term exposure to even low levels of pollution (below the recommended biomedical limits) may induce such health problems. They may be avoided if the households regularly analyse the quality of tap water and perform comparatively simple technical and hygenic interventions. A water laboratory has been established at Kilesandsgarden and an islander, specialized in water analyses, has been appointed head of this laboratory.

  • The brooks on Koster usually contain groundwater that may be mixed with domestic waste water. Well water communicates locally with the water in the watercourses. The more water that is taken from such wells, the greater the risk of pollution from domestic waste water systems leaking in. When a great deal of water is consumed, as during the tourist season, the groundwater level may fall and salt water from the sea will infiltrate the water supply. These threats may be reduced by keeping the island population watchful and by encouraging the summer residents and temporary visitors to save water and to protect the limited water resources on Koster.

  • Living near, on and from a sea constantly threatened by environmental change, a sea which provides less and less yield, may be a psychological strain. Anxiety, stress and depression are common symptoms in individuals who feel helpless in the face of different kinds of environmental threats to their health and economy. Such human reactions may induce the use of different forms of “doping”, such as greater alcohol consumption and tobacco use. The adoption of such negative life styles usually means further threats to the health of the human individual. The physical effects and psychological environmental changes as well as different kinds of abuses may amplify each other in the human body. The quantity of saliva may be reduced and its chemical composition may be altered. In this way the body’s natural protection of oral mucous membranes and the teeth may be diminished. Consequently, the underemployment induced by the environmental changes are serious threats - not only to the traditional cultural and social life of the islanders but also to their physical and mental health.

  • Close-up colour photographs of existing variations in human oral health status have demonstrated that the oral soft tissues may serve as a mirror of general health. Every individual has a unique pattern of reactions (oral “biological finger prints”). The close-up photographs have also come to serve as valuable tools of communication in informing individuals of threats to human health posed, for example, by tobacco consumption, and providing arguments and support for health-promoting measures.

  • During the last few years new environmental threats against human health have been identified on Koster. Changes in the cultural landscape, with increased growth of brushwood because of reduced farming on the islands, have indirectly increased the risks of tick-borne infections, such as borreliosis, ehrlichiosis and encephalitis. Furthermore, the solar UVB radiation has been found to be temporarily very strong on the sunny islands. The comparatively clear air in the region may favour high solar radiation. Therefore, the Koster Health project is providing the islands and the summer visitors with continuous information on how to avoid tick-borne infections and UVB induced disorders and, especially, how to protect the children against such hazards.

  • During the course of the project, each islander’s experience and knowledge concerning the impact of neighbouring environmental changes on human quality of life have been documented and stored in a database. A two-way communication process has been established. Thus, the islanders provide the academic staff of the project with valuable information and this new knowledge is systematized and analysed by the staff and returned to the population in the form of proposals for plans of action. Also other actors in the society are informed about the Koster Health experiences and interdisciplinary educational undergraduate, postgraduate, and adult educational programmes concerning the human condition in a changing environment are being developed. The aim of the programmes is to spread knowledge about the possibilities for the human individual to take an increased self-responsibility for his or her neighbouring environment and health - in accordance with the essence of Agenda 21.


Since 1995, the Koster Health project represents a new university unit at the Department for Interdisciplinary Studies of the Human Condition, Faculty of Thematic Studies, Goteborg University. It is entitled the “Section for Environment & Health - Koster Health”. Its scientific staff includes two professorships: one Professor in International Archipelago Research ( in collaboration with Abo Academy University, Finland) and one UNESCO-Cousteau Ecotechnie Chair in Human Response to Environmental Stress (in collaboration with UNESCO, Division of Higher Education, Paris, France).

For further information contact:
Professor Guy Heyden
UNESCO - Cousteau Ecotechnie Chairholder
Faculty of Thematic Studies - ORAL PATHOLOGY
Medicinaregatan 12,
S-413 90 Goteborg
Tel: +46 31 773 32 24 Fax: +46 31 82 68 05
E-mail: heyden@odontologi.gu.se