Pontificia Universidad Católica de Chile Pontificia Universidad Católica de Chile
Jorquera H., Barraza F., Heyer J., Valdivia G., Schiappacasse L.N. and Montoya L.D. (2018)

Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, Chile

Revista : Environmental Pollution
Volumen : 236
Páginas : 477-487
Tipo de publicación : ISI Ir a publicación


Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; however,little is known about the indoor air quality in this region. A field measurement campaign at 63 householdsin the Temuco urban area was conducted in winter 2014 and is reported here. In this study, indoorand outdoor (24-hr) PM2.5 and its elemental composition were measured and compared. Infiltrationparameters and outdoor/indoor contributions to indoor PM2.5 were also determined. A statistical evaluationof how various air quality interventions and household features influence indoor PM2.5 was alsoperformed.This study determined median indoor and outdoor PM2.5 concentrations of 44.4 and 41.8 mg/m3,respectively. An average infiltration factor (0.62 ± 0.06) was estimated using sulfur as a tracer species.Using a simple mass balance approach, median indoor and outdoor contributions to indoor PM2.5 concentrationswere then estimated as 12.5 and 26.5 mg/m3, respectively; therefore, 68% of indoor PM2.5comes from outdoor infiltration. This high percentage is due to high outdoor pollution and relatively highhousehold air exchange rates (median: 1.06 h1).This study found that S, Br and Rb were dominated by outdoor contributions, while Si, Ca, Ti, Fe and Asoriginated from indoor sources. Using continuous indoor and outdoor PM2.5 measurements, a medianindoor source strength of 75 mg PM2.5/min was estimated for the diurnal period, similar to literatureresults. For the evening period, the median estimate rose to 135 mg PM2.5/min, reflecting a more intensewood burning associated to cooking and space heating at night.Statistical test results (at the 90% confidence level) support the ongoing woodstove replacementprogram (reducing emissions) and household weatherization subsidies (reducing heating demand) forimproving indoor air quality in southern Chile, and suggest that a cookstove improvement programmight be helpful as well.