Abstract
BACKGROUND: Cooking and heating in households contribute importantly to air pollution exposure worldwide. However, there is insufficient investigation of measured fine particulate matter (PM(2.5)) exposure levels, variability, seasonality, and inter-spatial dynamics associated with these behaviours. METHODS: We undertook parallel measurements of personal, household (kitchen and living room), and community PM(2.5) in summer (May-September 2017) and winter (November 2017-Janauary 2018) in 477 participants from one urban and two rural communities in China. After stringent data cleaning, there were 67,326-80,980 person-hours (n(total) = 441; n(summer) = 384; n(winter) = 364; 307 had repeated PM(2.5) data in both seasons) of processed data per microenvironment. Age- and sex-adjusted geometric means of PM(2.5) were calculated by key participant characteristics, overall and by season. Spearman correlation coefficients between PM(2.5) levels across different microenvironments were computed. FINDINGS: Overall, 26.4 % reported use of solid fuel for both cooking and heating. Solid fuel users had 92 % higher personal and kitchen 24-h average PM(2.5) exposure than clean fuel users. Similarly, they also had a greater increase (83 % vs 26 %) in personal and household PM(2.5) from summer to winter, whereas community levels of PM(2.5) were 2-4 times higher in winter across different fuel categories. Compared with clean fuel users, solid fuel users had markedly higher weighted annual average PM(2.5) exposure at personal (78.2 [95 % CI 71.6-85.3] μg/m(3) vs 41.6 [37.3-46.5] μg/m(3)), kitchen (102.4 [90.4-116.0] μg/m(3) vs 52.3 [44.8-61.2] μg/m(3)) and living room (62.1 [57.3-67.3] μg/m(3) vs 41.0 [37.1-45.3] μg/m(3)) microenvironments. There was a remarkable diurnal variability in PM(2.5) exposure among the participants, with 5-min moving average from 10 μg/m(3) to 700-1200 μg/m(3) across different microenvironments. Personal PM(2.5) was moderately correlated with living room (Spearman r: 0.64-0.66) and kitchen (0.52-0.59) levels, but only weakly correlated with community levels, especially in summer (0.15-0.34) and among solid fuel users (0.11-0.31). CONCLUSION: Solid fuel use for cooking and heating was associated with substantially higher personal and household PM(2.5) exposure than clean fuel users. Household PM(2.5) appeared a better proxy of personal exposure than community PM(2.5).