AMBIENT AIR POLLUTION AND THE NEED TO IMPROVE INDOOR AIR QUALITY IN OUR EVERYDAY SPACES
COVID-19 has rapidly accelerated our understanding of the impact of ambient air on health and, in response, so too should our approach to how we operate buildings.
Literature reviews by agencies such as the World Health Organisation (WHO) and others have shown that long-term exposure to ambient air pollution increases mortality and morbidity from cardiovascular, respiratory disease and lung cancer, all of which shortens life expectancy.
As a result, the challenges for future reductions in the burden of disease attributable to air pollution are substantial. International experience has shown that exposure to ambient air pollution and its associated burden of disease can be lowered for entire populations via policy action at the national and subnational levels via aggressive air quality management programmes, focused on major sources of air pollution.
Particulate Matter (PM) is the collective name for fine solid or liquid particles added to the atmosphere by processes at the earth’s surface, and includes dust, smoke, soot, pollen and soil particles.
Air pollution is a complex mixture of gases and particles whose sources and composition vary spatially and temporarily. Population-weighted annual mean concentrations of particle mass with aerodynamic diameter less than 2·5 µm (PM2·5) is one indicator used to quantify exposure to air pollution. PM2·5 is the most consistent and robust predictor of mortality in studies of long-term exposure.
It is widely accepted that PM2.5 is hazardous to our health, as it can penetrate the lung barrier and enter the blood system.
Ambient outdoor air quality contributes directly to Indoor Air Quality (IAQ) because the introduction of fresh air (ventilation) into an air-conditioned building largely determines the quality of the IAQ. Higher ventilation rates are deemed to improve IAQ, and CO₂ is often a proxy for IAQ.
Consider the fact that your building may be pulling in a poor quality of fresh air, combined with other factors internally, such as off gassing of VOCs, photocopier dust as well as airborne pathogens from human occupants. You may not be aware of it, but the sealed building in which you may spend 90% of your time, may adversely affect your life – or improve it considerably.
Data-based insights hold the answer
With the advancement in sensor technology using Internet of Things (IoT) it is now possible to have a web-based dashboard providing real time IAQ measurements indicating a range of data from temperature to VOCs, PM levels as well as CO₂. Once you have the data, you can also consider various measures to improve IAQ beyond ventilation rates and filtration, that include various forms of air purification products. Much of the product development pre-dates COVID-19, where countries have already put in place guidelines and regulations around improving indoor air quality after early outbreaks of the SARS virus.
While some of the most advanced free-standing units focus on what is called the breathing zone, other technologies such as UVCGI and Photo Catalytic Oxidation (PCO) can be installed within the ducted systems of the air-conditioning plant operating as one integrated system. Schools, offices, hospitals and call centres have all gained significant benefit by installing monitoring systems as well as IAQ technologies.
Until now, the green building movement has largely targeted energy and water use because it was easy to measure with a few sensors and analysis of energy bills, with the return on the investment easily quantified. The shift to IAQ is more complex, however, and the investment provides a return based on the improved health of the occupants, which is hard to quantify on a balance sheet.