The annual mass concentrations of fine particulate fractions(PM2.5 and PM10) for four types of cultural/ritual and pureresidential indoors are listed in Table S2 and Fig. 2. During the study period, the range of annual average PM10 concentrations was 591.09e1816.07 mg m3 and those for PM2.5 was 436.14e1422.68 mg m3 in selected cultural/ritual-indoors; higher (2e7 fold PM10 and 2e8 fold PM2.5) compared to those measured in pure-residential indoors and associated ambient-outdoors and multifold higher compared to WHO standards for PM2.5 and PM10[39]. Occurrences of higher annual averaged values of aerosol fraction along with slightly higher PM2.5/PM10 ratios in ritual/cultural-indoors compared to residential-indoors and ambientoutdoors attributed to significant impact of emissions resulting from indoor combustion sources [11]. Cultural/ritual indoor PM concentrations were also comparatively higher than temples in Hong Kong during peak and non peak periods [23].