Variation of indoor and outdoor carbonaceous aerosols in rural homes with strong internal solid fuel combustion sources

Organic carbon (OC) and elemental carbon (EC) are important components of particulate matter and contribute significantly to the health and climate impacts of aerosols. In this study, we evaluated indoor and outdoor OC and EC concentrations in the total suspended particle (TSP) contents and their seasonal variations in rural households with strong indoor solid fuel combustion sources. The 24-h average indoor TSP, EC and OC concentrations were 470 ± 256, 7.9 ± 10.9, and 75 ± 114 μg/m3 during the non-heating period and increased to 691 ± 287, 19 ± 9, and 192 ± 97 μg/m3 during the heating period, respectively. The seasonal differences were statistically significant (p < 0.05). The increments in OC and EC concentrations were larger in outdoor air than in indoor air. OC and EC were correlated, with more significant correlations in indoor air compared to outdoor air and stronger correlations during the heating period compared to the non-heating period. In winter, the total carbon (TC=EC+OC) mass fractions in TSP increased obviously, primarily because of coal burning for indoor environments.