Blue Flag Beaches-Bathers at Risk for Thalassogenic Diseases

Abstract

If beaches and water are polluted by wastewater, bathers are at risk for thalassogenic diseases such as diarrhea, skin infection, respiratory tract infection and hepatitis. The coastal water around the Cape Peninsula in South Africa is affected by polluted rivers that flow into the ocean, major shipping routes and wastewater outlets of human settlements. With high tide the water from offshore is brought onto the beach area and towards the coastline.
Results: Sea water was collected from the eco-labeled Blue Flag beach, Clifton, Cape Town, during peak season in February and March 2013 at high tide to culture E. coli. The tested water quality was between 104 and 106, indicating that Clifton Blue Flag beach is affected by waste water. Foam and yellowish coloring of sand was associated with elevated E. coli counts. Data of water analysis are only displayed at Blue Flag beaches with a delay of two to three weeks.
Conclusions: Swimming on a Blue Flag beach does not exclude time limited waste water pollution. Regular external and independent quality surveillance of Blue Flag beaches is mandatory, besides more rapid measurement and timely display of water analysis. Especially infants and people with HIV and/or Tb infections are at risk for health hazards as they are immune compromised. Swimmers should be aware of the risk they are taking when bathing in polluted water and know the signs of waste water pollution. Due to the high burden of HIV and Tb infection, further large scale studies are needed to evaluate the health effects for bathers besides the economic impact of improved wastewater treatment in South Africa.