It is all around us, but unless there is a problem, we usually do not concern ourselves with what is in the air that we breathe. In both indoor and outdoor environments, poor air quality can greatly impact our health and well-being. Two important indicators for air pollution measurement are small particulate matters (PM) of 2.5 microns or less (PM2.5) and volatile organic compounds (VOCs). They are, for example, emitted in households by fireplaces and candles during combustion processes. Everyday objects such as cleaning supplies, furniture, or textiles can also emit VOCs.
Personal PM2.5 monitoring
We know that exposure to particulate matter can cause serious health problems, and the World Health Organization (WHO) says, "By reducing air pollution levels, countries can reduce the burden of disease from stroke, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma1."
While particulate matter comes in a vast range of particle sizes, the biggest impact to human health is from particulates in the PM2.5 range2, which are smaller than 2.5 µm (microns) in diameter. These minute PM2.5 particulates can easily enter deep into the lungs and cause serious health problems. Although research is still ongoing, there is evidence that PM2.5 exposure can be linked to sensitivity to viral diseases, including SARS-CoV-2, as discussed in a recent study by Harvard University3.
Official air quality monitoring stations provide only consolidated or averaged data for the outdoor environment without the corresponding indoor air data. They do not generate personalized information and only measure air quality in their immediate vicinity that is averaged-out over a time period, and thus lack real-time information for tracking the rapidly-changing environment around us and for monitoring the fluctuations in local PM levels.