A public health specialist says the maximum allowable level of nitrate in drinking water should be 11 times lower than current rules allow.
Otago University's Dr Tim Chambers is part of a Ministry of Health appointed research group investigating links between nitrate and colorectal cancer.
He says the allowed rate of 11.3 mg/L should be slashed to 1mg/L.
RNZ today revealed dairy factory wastewater has contaminated the private water bores of people living close to where it's spread.
Our reporter Farah Hancock spoke to Dr Chambers and asked if international research linking nitrates with colorectal cancer is robust.
