What began as a movement in the UK has been brought here and supported by NZ doctors who are active in the community.
Why Suppress Airborne Virus Transmission
The evidence base below, based on research by scientists and engineers, outlines the case for action. The Covid-19 Safety Pledge NZ provides scientific evidence and references throughout, including early signals from pre-print findings where relevant to our rapidly improving understanding of the virus.
Specific medical conditions increase in frequency following infection and become more likely with each infection (chart below).
COVID-19 transmission has now become widespread within New Zealand, with more than 3 million people estimated to have had the virus. However this only makes it more important that we continue to take action against the virus.
However clean air actions are needed because vaccination cannot entirely prevent infection or transmission. At 20 weeks following vaccination nearly all will be able to catch and transmit Omicron (Page5, Figure1).
Clean air dilutes and takes away contaminated air. Clean indoor air works on any variant and any airborne disease. Increasing and enhancing ventilation with clean air makes indoor places more like the outdoors, significantly reducing the risk of COVID-19 transmission and it doesn’t take away anyone’s freedom. The closer indoor CO2 levels are to outdoor CO2 levels of 420ppm the lower the risk.
Minister of Health, Dr Ayesha Verrall (14 July 2022).
How effective is clean air ?
In addition to improved productivity and reduced short-term illness, studies show that clean air ventilation at 20L/sec/person can reduce COVID-19 risk by 80% (approx = 5-6 air changes per hour with 1.25m distancing).
When air was replaced 2.4 times an hour by the ventilation system, infections were lowered by 40 per cent
When air was replaced four times an hour, infections were lowered by 66.8 per cent
When air was replaced six times an hour, infections were lowered by 82.5 per cent
For building owners and managers ventilation is your first priority.
Masking offers triple protection. It protects the wearer, people nearby as well as others indoors in the same area. Masks work on any variant.
The cost of masks
N95 masks can theoretically be used 200 days in total and are approximately NZ$1.80 each. They can be used for a standard working week (up to 40 hours ,5 x 8hr ) then re-used after resting for 3 days (provided the mask still fits well). This means the average cost is 9 cents/day.