Beach waters may at times pose a health risk to bathers due to pollution or contamination. Alameda County Department of Environmental Health provides the public with information
regarding such occurrences. Please see the Archive to review the history of beach advisories.
Swimmer's Itch
Swimmer's itch, also called cercarial dermatitis, appears as a skin rash caused by an allergic reaction to certain parasites that infect some birds and mammals. These microscopic parasites are released from infected snails into fresh and salt water (such as lakes, ponds, and oceans). While the parasite's preferred host is the specific bird or mammal, if the parasite comes into contact with a swimmer, it burrows into the skin causing an allergic reaction and rash. Swimmer's itch is found throughout the world and is more frequent during summer months.
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Tarballs: What are they, and how are they formed Tarball (370Kb)*
