New health warnings have been issued by the Waikato District Health Board for the Hamilton residents walking their pets as they have found higher levels of cyanobacterial cells, also known as blue green algae scum along the northern shore of Lake Rotoroa and other four lakes outside Hamilton including in the list Ngaroto, Whangape, Hakanoa and Waikare lakes.

The health board has informed that Lake Rotoroa (Hamilton's largest lake) had become a more significant health risk factor since a health warning was issued in mid-February and probabilities are higher that the blue-green algae has since formed scum due to the wind, particularly around the northern shores of the lake.

Further the health board has marked some tips: even a mere contact with the scum around the lake is hazardous, especially to children and pets. Thus, it’s important that their skin must be rinsed thoroughly and clothing should also be changed as soon as possible if anyone came into contact with it. All the activities in the lake should be barred during the blooms especially and also swallowing water from lakes should also be avoided.

Some of the informed risks from the blue-green algae are rash, skin and eye irritation, allergy symptoms such as hayfever and asthma and possibly diarrhoea and vomiting.