A medical advisor says new research linking nitrates in New Zealand's water to an increased risk of bowel cancer is misleading.
The study, which was overseen by Victoria and Otago universities, found that 800,000 Kiwis may be exposed to levels of nitrates that may increase the risk of developing bowel cancer.
But Bowel Cancer New Zealand medical advisor Frank Frizelle tells Newshub Kiwis shouldn't be panicking just yet.
"I can be almost certain it won't be nitrates in the water," he says.
New Zealand has one of the highest rates of colorectal cancer in the world.
The new research found one in six Kiwis are drinking water with nitrates at a level that a Danish study of 2.7 million people linked to bowel cancer.
"We're just pointing out a correlation between nitrates and drinking water from a bunch of studies from around the world and that it's increasing in our waters and we worked out how many New Zealanders are getting this high level of nitrate," freshwater ecologist Mike Joy says.
The study is causing anxiety among some rural Canterbury residents who are now scrambling to test their water, but Frizelle believes the study is misleading.
"There's no reason to think having high levels of nitrates in our water is something we should tolerate in the community, but if you want to say that increased nitrates is causing bowel cancer I think it's very questionable."
Director-General of Health Dr Ashley Bloomfield says the Ministry of Health agrees.
"It's one to watch but it's very early and it's just an estimate based on overseas data."
Bowel Cancer New Zealand says reducing the risk may come down to more than just the water you drink.