An upper bound on one-to-one exposure to infectious human respiratory particles | PNAS
Masks just work:
Our results show that face masks significantly reduce the risk of SARS-CoV-2 infection compared to social distancing. We find a very low risk of infection when everyone wears a face mask, even if it doesn’t fit perfectly on the face.
(tags: masks covid-19 papers face-masks infection)
Ikea Vindriktning Air Quality Sensor Review and Accuracy
‘Ikea recently came out with a range of air purifiers and also an air quality sensor. The Vindriktning does not have a display but shows the air quality data in the form of a traffic light with red, yellow and green LEDs. One of the most striking features is actually the price as it costs only around EUR 10 depending where you live. It looks very nice and the build quality is quite good but this article will look beyond the looks and see how good it is at actually measuring the air quality.’ The results are mixed: ‘I really want to like the Vindriktning! It has a great built quality and price and is very simple to use. The addition of a small fan to improve the air flow through the sensor is a good upgrade and shows that Ikea wants to provide accurate measurements — even with a cheap sensor. However, the defined cut off values for the air quality and its description as “Good”, “OK”, and “Not Good” are not based on science or international recommendations and create the false understanding that the air is good, when in fact it is not good at all. I do hope that in one of the next upgrades of the Vindriktning, Ikea will bring its traffic light indicators more in line with WHO recommendations on healthy air quality.’ Personally, this sounds useful — as long as one remembers that the “OK” air quality level is in fact well into the “unhealthy” zone. Bit mysterious as to why IKEA made this choice though…
(tags: ikea air-quality pm2.5 pm10 particulates home devices gadgets)