Abstract

 Evidence linking micobe-laden sediments to health effects in humans is generally very difficult to find. Sediments are formed when particulates wash into lakes, oceans and rivers, settle and accumulate at the bottom of the water column. The source of the particulates can be domestic or industrial waste-waters, or rain water run-off from pastureland or forests. Many of these wastes or run-off materials contain fecal material, which may harbor pathogens that could pose a hazard to humans. The survival of microbes in sediments, especially when adsorbed to or encapsulated by particulates, is well documented. It is the re-suspension of these particulates in recreational waters or shellfish harvesting waters that are a cause for concern. This presentation will examine one of the more common exposures of humans to sediments that may contain microbial pathogens. Swimming in natural bathing waters provides an activity that may shed some light on the health effects that may be associated with sediments or particulates in the water column. Although it is impossible to separate natural re-suspension of sediments by wave action from re-suspension due to human activities, it is possible to examine microbes in particulates and determine if they are associated with health effects in swimmers. The results of a study of the relationship between particulates and swimming-associated gastroenteritis will be presented and the implications of the findings for other exposures will be examined.