Health warnings that were in place at two lakes in the MidCentral District Health Board region that previously had high levels of potentially toxic blue green algae (cyanobacteria), have been cleared for use again, after health warnings were lifted.
Tests carried out in late November by Horizons Regional Council showed very high levels of potentially toxic blue-green algae (cyanobacteria) at Lake Wiritoa, near Whanganui and Lake Dudding in Rangitikei.
Health warnings were in place at both lakes. People were advised not to use the water for recreational purposes until these warnings were removed.
Cyanobacteria (also known as blue-green algae) may produce toxins that are harmful to humans and animals if swallowed or through contact with skin, such as may occur when swimming, water skiing or kayaking.
Exposure to cyanobacterial toxins may cause symptoms such as skin rashes, nausea, tummy upset and tingling and numbness around the mouth or finger tips.
Horizons Regional Council monitors cyanobacteria in our recreational lakes during summer and the public will be advised of any changes in water quality that could be associated with health problems.
Not all cyanobacterial blooms are visible and toxins can persist after the bloom has disappeared. Cyanobacterial concentrations can change quickly with changing environmental conditions (e.g. wind). When a health warning is in place, people are advised to avoid contact with the water.
Public Health Centre, MidCentral Health, Whanganui Hospital, on 06 348 1775 or Public Health Services, MidCentral Health, on (06) 350 9110.