Fact or fiction: Winston Peters says masks 'worthless' after going maskless at protest

Former Deputy Prime Minister Winston Peters has defended his decision to wear no mask among a throng of protesters outside Parliament at the peak of the Covid-19 outbreak.

Speaking at the time and in subsequent interviews, Peters said masks were "worthless" unless they were medical-grade. He also said journalists were not up with the latest medical science on the issue.

The Herald spoke to an expert to fact-check his claims.

Winston Peters: Unless masks are "highly surgical of a certain scientific and medical content" they are a "waste of time".

The facts: Peters is right that some masks are more effective than others. But that is not a reason to go without, said University of Auckland aerosol scientist Dr Joel Rindelaub. And even surgical masks worn properly can be highly effective.

"Any mask is better than no mask," Rindelaub said.

"With case numbers skyrocketing right now, if you are interacting with people without wearing a mask, you are not helping.

"There are certainly masks that work better than others, specifically the N95 or P2 varieties, which would be the best to use in our current situation.

"But regular surgical masks are also effective and readily available, and there are ways that you can modify them to help them work harder for you."

American expert panel ACGIH pandemic task force found that if two people were wearing a surgical mask, it would take an hour for a person to become infected with Covid-19. With two people wearing N95s, the timeframe rises to 25 hours.

Infection is much less likely to occur outdoors, and Peters met with protesters outside Parliament.

"But lower risk does not mean no risk," Rindelaub said. "And we have seen instances where transmission has happened in outdoor environments, especially in crowded areas."

"Any time you are talking or raising your voice you are going to be expelling significantly more aerosol particles, and if there's Covid in there that's going to be a big issue."

Winston Peters: "It would be wise for you to get up with the medical science on this matter."

The facts: "The medical research on mask use has actually pointed to their importance even more since early in the pandemic, and we have better data that shows they actually are effective," Rindelaub said.

He pointed to a study in Bangladesh of nearly 350,000 people, split into a mask-wearing group and a control group, which found that surgical mask use led to lower incidence of symptomatic Covid infection. The gold-standard research backed up hundreds of previous laboratory and observational studies.

The reduction in infection was much higher among higher-risk people, including older people. Peters is 76.

The type of mask was important. The Bangladesh study showed an 11 per cent drop in risk for people wearing a surgical mask, and just a 5 per cent drop in risk for cloth masks.

The science is not the only thing evolving when it comes to masks. It appears Peters' own views have changed over time.

"Put your masks on, be smart," Peters said in June 2020, referring to the large number of people flying maskless on Air New Zealand.

"I get on the plane and I say, 'Where's the masks?' They say, 'We're not doing that anymore,' and my question is, 'Why not?", Newshub reported.

Under red light settings, the Ministry of Health recommends that people wear a mask when it is difficult to physically distance from anyone you do not know, or at a gathering.

It also says you should wear one at your place of work. On this point, Peters is off the hook. He has not worked at Parliament since 2020.