Water-Associated Human Illness in Northeast Pennsylvania and its Suspected Association with Blue-Green Algae Blooms

Abstract

On August 8, 1979 the Bureau of Community Environmental Control, Department of Environmental Resources, in collaboration with the Pennsylvania Department of Health, undertook the investigation of an outbreak involving 12 children and one adult at a lake-shore community located in northern Monroe County.

Within the next two weeks, three additional outbreaks occurred at another lake heavily used for recreational purposes in Pike County, approximately 20 miles away from the first site.

Though symptoms, referred to by local doctors as summer flu, varied widely, contact with the lake waters was found to be a common factor at both lakes. Symptoms which ranged from gastrointestinal involvement to hayfever-like symptoms came upon the affected individuals either during a period of water contact or within several hours thereafter.

Testing for standard bacterial contaminants in both the lake waters and consideration of possible viral contaminants provided no clues to the causitive agent or agents involved.

Investigation was then conducted of comments made by several of the individuals interviewed that the lakes were considerably dirtier this summer and that the larger lake was taking on a decidedly green color. This led to the discovery of very large numbers of the blue-green algae genus Anabaena in the waters of the larger of the two lakes.

As very little information was available through official channels on any ties between blue-green algae and human sickness, much time was lost in attempting to determine if the algae could be the causitive agent. Although a search of the available literature eventually showed that at least three of these outbreaks had a high probability of being caused by the blue-green algae genus Anabaena, a more critical study is obviously needed. Recommendations have been submitted that an in-depth study be conducted with the intent of developing maximum allowable levels for toxin-producing algae or the actual toxic substances produced for beaches and other water-associated recreation sites.