Singapore’s online newspaper TODAY, produced by MediaCorp, carries an article today (14 September) that seeks to clarify confusion over which air quality index we should refer to when deciding whether to venture outside now that the haze is back. You can read the article here. I am not sure that I am any less confused having read the article.
I prefer to use a scale that matches air quality (and in particular the concentrations of small particles, or PM2.5) to the equivalent numbers of passively smoked cigarettes, published by van der Zee et al in 2016 in the journal Environmental Pollution. This scale assumes that there is no safe level of PM2.5.
Van der Zee is based in the Public Health Service of Amsterdam, Netherlands. He and co-workers determined that every 10 ug/m3 increment in PM2.5 corresponded to on average between about four to seven, passively smoked cigarettes per day. With PM2.5 concentrations in Singapore approaching 100 ug/m3 that equates to at least 40 passively smoked cigarettes. Let’s not forget that smoking in public places was banned because of the health risks of passive smoking.
To be honest, many people in the environment get sick because they become passive smokers, for some reason people still do bad things to the people closest to them.