Indoor Air Pollution from Residential Stoves: Examining the Flooding of Particulate Matter into Homes during Real-World Use

• Main Authors: Rohit Chakraborty, James Heydon, Martin Mayfield, Lyudmila Mihaylova
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Atmosphere
• Subjects: air pollution; wood burning stoves; particulate matter; particle number concentration; indoor air quality; low-cost sensors
• Online Access: https://www.mdpi.com/2073-4433/11/12/1326

This study concerns the levels of particulate matter (<inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mrow><mn>2</mn><mo>.</mo><mn>5</mn></mrow></msub></semantics></math></inline-formula> and <inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mn>1</mn></msub></semantics></math></inline-formula>) released by residential stoves inside the home during ‘real world’ use. Focusing on stoves that were certified by the UK’s Department of Environment, Food, and Rural Affairs (DEFRA), PM sensors were placed in the vicinity of 20 different stoves over four weeks, recording 260 uses. The participants completed a research diary in order to provide information on time lit, amount and type of fuel used, and duration of use, among other details. Multivariate statistical tools were used in order to analyse indoor PM concentrations, averages, intensities, and their relationship to aspects of stove management. The study has four core findings. First, the daily average indoor PM concentrations when a stove was used were higher for <inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mrow><mn>2</mn><mo>.</mo><mn>5</mn></mrow></msub></semantics></math></inline-formula> by 66.24% and <inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mn>1</mn></msub></semantics></math></inline-formula> by 69.49% than those of the non-use control group. Second, hourly peak averages are higher for <inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mrow><mn>2</mn><mo>.</mo><mn>5</mn></mrow></msub></semantics></math></inline-formula> by 55.34% and for <inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mn>1</mn></msub></semantics></math></inline-formula> by 57.09% than daily averages, showing that PM is ‘flooding’ into indoor areas through normal use. Third, the peaks that are derived from these ’flooding’ incidents are associated with the number of fuel pieces used and length of the burn period. This points to the opening of the stove door as a primary mechanism for introducing PM into the home. Finally, it demonstrates that the indoor air pollution being witnessed is not originating from outside the home. Taken together, the study demonstrates that people inside homes with a residential stove are at risk of exposure to high intensities of <inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mrow><mn>2</mn><mo>.</mo><mn>5</mn></mrow></msub></semantics></math></inline-formula> and <inline-formula><math display="inline"><semantics><msub><mi>PM</mi><mn>1</mn></msub></semantics></math></inline-formula> within a short period of time through normal use. It is recommended that this risk be reflected in the testing and regulation of residential stoves.