Sadly from 2019 (mid to end) into 2020 Australia has been the midst of a Bushfire Crisis, with a significant amount of land which has been burnt by fire. Estimates have placed the size of the fire at around 10 million hectares (or 15.6 million acres) as of around Mid January 2020. These fires have also claimed the lives of up to 28 people including four firefighters.
The fires have primarily been spread across New South Wales, Victoria and South Australia (Primarily Kangaroo Island) . The smoke as a result of the fires has been significant leaving many Australian states shrouded in smoke, and in some cases (due to winds) spreading as far as New Zealand and as far out as Central Chile (https://www.theguardian.com/australia-news/2020/jan/07/australian-bushfire-smoke-drifts-to-south-america-un-reports).
Bushfire smoke is complex and contains a range of pollutants, it contains different sized particles, water vapour and gasses which include carbon monoxide, carbon dioxide and nitrogen oxides. (https://www.health.qld.gov.au/news-events/health-alerts/bushfire-smoke-health-alert). The particles vary in size and composition which can affect their toxicology, larger particles tend to get caught up by the bodies filtering systems whilst the smaller particles (e.g. PM2.5) are more likely to get further into the lungs and aggravate existing lung and heart conditions. In addition irrespective of the size, the particles can irritate the eyes, nose and throat.
A number of countries worldwide have what is known as an Air Quality Index (AQI), this rates the air quality from Very Good (0 – 66) through to Hazardous (>200) and gives recommendations for healthy adults and higher risk populations (e.g. When Hazardous Healthy Adults should “Significantly cut back on outdoor physical activities”, whilst higher risk populations should “Avoid all outdoor physical activities”) (https://www.health.nsw.gov.au/environment/air/Pages/faqs.aspx).
There are a number of data aggregation sites which can provide the AQI for major capital cities and other areas, one of which is known as AQICN (https://aqicn.org). Typically bushfires result in poor AQI due to the PM2.5 and/or PM10 concentrations. In January 2020, within Melbourne alone there were two days where the AQI (PM2.5) was between 200 – 300, Sydney had one day where the AQI (PM2.5) was between 125 – 150.
Meanwhile Canberra had 2 days where the AQI (PM2.5) was greater than 400, 1 day where it was between 300 – 400 and 2 days where it was between 200 – 300. For a short period of time on around the 2nd or 3rd of January 2020, Canberra had the worst air quality in the world (https://www.theguardian.com/australia-news/2020/jan/03/canberra-chokes-on-worlds-worst-air-quality-as-city-all-but-shut-down).
Sadly bushfires are not uncommon within Australia, this has not been our first bushfire nor will it be our last however the intensity and ferocity of the fires has taken most by surprise. Generally speaking bushfires affected those communities who were impacted by the fires but less so other area(s) however, due to the widespread smoke it has had a significant impact on a much larger population (e.g. capital cities) who have been out buying P2 / N95 masks like crazy (Fitting Guide: https://www.health.nsw.gov.au/Infectious/factsheets/Pages/q-fever-p2-mask.aspx, side note P2 masks are not designed for children and those under around 12).
This won't be our last bushfire (sadly), but it has highlighted the importance as a country for us to plan our climate change responses (and adapt in the case of new information). It has also in my mind (working in indoor air quality) highlighted just how much further we have to go to help people understand the importance of good air quality, the fact that there are not defined standards for acceptable indoor air quality in Australia in early 2020 boggles the mind…