We propose a low-cost passive method for monitoring long-term average levels of light-absorbing carbon air pollution in polluted indoor environments. Building on prior work, the method here estimates the change in reflectance of a passively exposed surface through analysis of digital images. To determine reproducibility and limits of detection, we tested low-cost passive samplers with exposure to kerosene smoke in the laboratory and to environmental pollution in 20 indoor locations. Preliminary results suggest robust reproducibility (r = 0.99) and limits of detection appropriate for longer-term (~1-3 months) monitoring in households that use solid fuels. The results here suggest high precision; further testing involving “gold standard” measurements is needed to investigate accuracy.
Authors: Lara P Clark, V Sreekanth, Bukin Bekbulant, Michael Baum, Songlin Yang, Pao Baylon, Timothy R Gould, Timothy V Larson, Edmund Y W Seto, Chris D Space, Julian D Marshall
; Full Source: Sensors (Basel, Switzerland). 2020 Jun 17;20(12):E3417. doi: 10.3390/s20123417.