Epidemiological Studies Related to the Use of Sewage Sludge in Agriculture

Summary

The present knowledge and future research needs for epidemiological studies related to the use of sewage sludge in agriculture were discussed in a Workshop, organized by COST 681 Working Party 3, in Metz (F) from May 21–23, 1985. The discussions considered four separate themes: bacteria, parasites, viruses and occupational hazards. One conclusion, common to all themes, was that there exists a need for better surveillance of sludge exposed (human or animal) populations and adequate reporting of surveillance data. These data would give a continuous flow of information, and could indicate the need for more detailed epidemiological studies in particular cases or areas.

Such studies were at present considered necessary only with regard to parasites, because it was concluded that the guidelines proposed in the draft EEC directive were not always sufficient to prevent parasitic infections.

Sufficient knowledge was present with regard to risk assessment and prevention of bacterial infections. Little was known about viral infections or occupational hazards related to land use of sludge, but epidemiological studies were not recommended because of the complexity of the design and the small chance to obtain conclusive results.

It was again stressed that adequate prevention of sludge transmitted infections requires measures that depend on local situations with regard to such factors as prevalent infections, type of animal husbandry, availability of land, climate, etc. Guidelines, in particular those from supranational bodies such as EEC, should take this into account and local authorities should, where necessary, require further steps to be taken.