Or contact a journalist.
Overseas media have now
started “fact-checking” in an attempt to assist in some debates.
Launched in May 2023, BBC Verify is “a new brand to address the growing threat of disinformation and build trust with audiences by transparently showing how BBC journalists know the information they are reporting”.
Mediabiasfactcheck.com operates internationally and in 2023 rated mainstream New Zealand media generally highly for facts, while noting “emotionally and value-laden words” in reporting.
In a competitive market, the laden words are used to attract attention, and debates amongst scientists, particularly when the environment or health are involved, are clickbait joy.
The recent controversy around nitrate in water, impact on health, and the role of dairy cows makes the point.
Fact-checking in this case didn’t involve going back to the actual research.
The Danish study suggesting that elevated nitrate levels in drinking water are causing colorectal cancer was not supported in a wider study published in 2019.
The Danish study could not control for individual-level information on lifestyle and diet, nor did it find a dose-related response to nitrate.
This did not stop research based on the Danish study, resulting in headlines such as “Up to 800,000 New Zealanders may have increased bowel cancer risk due to nitrates in water”.
Nitrate in the diet is digested from the stomach (and recycled) – it doesn’t reach the bowel, and so there is no plausible mechanism for dietary nitrate to cause bowel cancer.
Despite statements to the contrary, experts such as professor of colorectal surgery Frank Frizelle say that “the association is loose”.
Association is not causation.
Other health scares have linked nitrate to preterm babies (born before 37 weeks of gestation).
University of Auckland research shows the rate of preterm birth differs by ethnic groupings (Māori 9%, Indian people 8.8%, Pacific people 8.1%, and Pākehā 7.1%).
There are also differences by region.
Listen to Jamie Mackay interview Dr Jacqueline Rowarth on The Country below:
The Te Whatu Ora Report on Maternity web tool gives Manukau (9.6%), Taranaki (9.4%) and Hutt Valley (9%) at the higher end, Hawke’s Bay (8.2%), Waikato at 7.8% and Auckland at 7.7%.
Canterbury, South Canterbury and Southern all have lower preterm incidence than Auckland.
University of Otago research published in 2015 reported that smoking during pregnancy and domestic abuse were associated with preterm babies.
Nitrate was not mentioned.
Or is it blue-baby syndrome (methaemoglobinaemia) that is the real concern?
The World Health Organisation (WHO) has reported that the incidence of babies globally has been reducing since the 1950s and is largely secondary to other causes of ill-health.
The WHO states that water used for bottle-fed infants must be microbiologically safe when nitrate is present at concentrations near the guideline value.
Research in all these areas continues.
WHO is on constant alert for new research and implications.
So are scientists in NZ, as they examine environmental changes and health statistics.
As for the dairy cows, there is plenty of research (summarised in various Hot Topics) indicating their contribution to nitrate in dairy water is small in comparison with turnover of organic matter, gorse and septic tanks.
And that the original calculations on the contribution from a dairy cow urine patch was based on measurements from housed cows in America last century, rather than NZ’s pasture-based animals.
The data from Lincoln University this century make the differences clear – if the urine is half the concentration and the size of the patch is double, as scientists from Lincoln report, then the loading is reduced by four times.
Further research has shown that virtually all the nitrate arriving in urine is taken up by the plant, and that is why we can see darker green patches on pasture after grazing.
Given all of this background, it is disappointing that public money continues to be invested in surveys to protect the public from a problem that has not been shown to exist.
Scientists and academics rarely use absolute terms such as “never” or “complete certainty” because they know that elements interact and changes occur.
They have open minds about integrating new information and discussing alternative implications with peers.
This is how science advances.
For fact-checking, primary sources – the actual research indicating the facts, evidence and data - are always the place to start.
