A local study first of its kind conducted by Dr Noel Aquilina and Dr Sara Camilleri from the Department of Chemistry and from the Faculty of Science respectively at the University of Malta, has just been internationally published in the journal Building and Environment on ScienceDirect. The study is entitled “Impact of daily household activities on indoor PM2.5 and Black Carbon concentrations in Malta”
Why study the local
Research in the last decade has shown when people spend about 90% of their time indoors, the overall exposure to particulate matter (PM) and other pollutants is often greater indoors than outdoors. The chemistry occurring in indoor environments is different and largely unknown because of unique sources and complex factors that are not present in the outdoor environment such as interactions of pollutants between building and furnishing materials, ventilation conditions, light, temperature and humidity. Various activities in the indoor environment also determine and effect the indoor pollutant levels.
Why particulate matter (PM) and Black Carbon, also known also as soot?
The latest WHO Air Quality Guidelines (AQGs) of 2021, have been updated and are more stringent. A PM2.5 daily limit value of 15 μg m-3 instead of the older 25 μg m-3 is advocated. No AQGs are established for soot, so no comparisons can be made for this pollutant. The daily PM2.5 limit of 25 μg m-3 was exceeded on 6 and 3 days out of the 90 days of measurements in our outdoor and indoor measurements, respectively. If a 15 μg m-3 daily limit is implemented, we find 17 and 10 days with higher daily outdoor and indoor PM2.5 concentrations, respectively. The change in the AQGs already indicates that it is going to be a challenging feat to continue reducing further the PM levels in both indoor and outdoor environments.