Abstract. Measurements of temporal and spatial changes to indoor contaminant
concentrations are vital to understanding pollution characteristics. Whilst
scientific instruments provide high temporal resolution of indoor pollutants,
their cost and complexity make them unfeasible for large-scale projects.
Low-cost monitors offer an opportunity to collect high-density temporal and
spatial data in a broader range of households. This paper presents a user study to assess the precision, accuracy, and
usability of a low-cost indoor air quality monitor in a residential
environment to collect data about the indoor pollution. Temperature,
relative humidity, total volatile organic compounds (tVOC), carbon dioxide
(CO2) equivalents, and fine particulate matter (PM2.5) data were
measured with five low-cost (“Foobot”) monitors and were compared with data
from other monitors reported to be scientifically validated. The study found a significant agreement between the instruments with regard
to temperature, relative humidity, total volatile organic compounds, and
fine particulate matter data. Foobot CO2 equivalent was found to
provide misleading CO2 levels as indicators of ventilation. Calibration
equations were derived for tVOC, CO2, and PM2.5 to improve
sensors' accuracy. The data were analysed based on the percentage of time
pollutant levels that exceeded WHO thresholds. The performance of low-cost monitors to measure total volatile organic
compounds and particulate matter 2.5 µm has not been properly
addressed. The findings suggest that Foobot is sufficiently accurate for
identifying high pollutant exposures with potential health risks and for
providing data at high granularity and good potential for user or scientific
applications due to remote data retrieval. It may also be well suited to
remote and larger-scale studies in quantifying exposure to
pollutants.
The Temporal and Spatial Distribution of Volatile Organic Compounds(VOCs) in the Urban Residential Atmosphere of Seoul, Korea