International Standards for Drinking-Water [antikvár]

PREFACE The World Health Organization has long appreciated the need for some form of international agreement and co-operation on the requirements for safe and potable water supplies. This problem becomes particularly pertinent with the great increase in travel, especially air travel, where common carriers must be watered at many points in the world, and the traveller must be furnished with acceptable drinking-water that will not produce unfavourable effects on his health. The status of water treatment and quality in the Member States of the World Health Organization was the subject of a questionnaire circulated in 1953. The replies clearly indicated the magnitude of the problem and the need for attention by the World Health Organization. As a result, groups of experts in sanitation and water treatment were convened in several of the regions of WHO to consider all problems related to standards of water quality. Since standards of quality are dependent upon the techniques used in the laboratory, the recommendations as to the specific methods to be used were an integral part of these discussions. The reports of the regional groups proved a valuable basis for the deliberations of a further study group, composed of experts from these regions and from elsewhere, which met in Geneva in 1956. The standards proposed by that group make up the present publication. In considering their assignments, the study group felt that the term " standards " should be applied to the suggested criteria of water quality, even though these are considered to be tentative and subject to modification after experience in their application. With laboratory methods, on the other hand, it was believed that these should not be designated as " standard methods ", since it is certain that with further use and study these may well be changed in major as well as minor details. Thus the laboratory methods prepared are proposed as "approved methods". In the preparation of the material for this publication, particularly in the sections devoted to laboratory techniques, full use was made of many sources, chiefly The Bacteriological Examination of Water Supplies of the Ministry of Health and the Ministry of Housing and Local Government for England and Wales, and Standard Methods for the Examination of Water, Sewage, and Industrial Wastes, 10th edition, of the American Public Health Association. _ 7 _