3.4. Annual trend and seasonality associated to source emitted aerosol OC and EC
Occurrence of significant higher concentrations and substantial variation in relative strengths of eight fractions of OC and EC in cultural/ritual-indoors compared to ambient-outdoors underscores the need to investigate seasonal variation pattern, indoor/outdoor contribution and comparison with pure residential-indoors. An extended longitudinal measurement campaign of total OC and total EC in PM fractions of existing cultural/ritual-indoors alongwith residential-indoors and ambient-outdoors has been conducted throughout the sampling year. The annual average concentration of carbonaceous aerosols in PM2.5 and PM10 are shown in Table S3 and Fig. 2. It is clearly evident from the results that annual average of PM2.5-OC in cultural/ritual-indoors is observed tobe 2.13e9.24 folds
and 2.86e12.42 folds higher compared to residential-indoors and ambient-outdoors, respectively. Similar trend occur in case of PM10-OC with 2.17e9.16 folds and 2.91e12.28 folds higher than residential-indoors and ambient-outdoors. EC is also found higher in both PM fractions measured in cultural/ritual-indoors compared to residential-indoors and ambient-outdoors. PM2.5-EC was found 2.58e5.44 and 3.98e8.40 folds higher and PM10-EC was 2.62e5.25 and 4.0e8.0 folds higher on comparing with those found in residential-indoors and ambient-outdoors, respectively. The findings of OC/EC annual averages are much higher than other those reported for other residential measurements [49]. The relative order of selected sites for the occurrence of OC is MHS > MP > BT > HT and for EC is MP > BT > MHS > HT. MHS-indoors have shown 1.33e4.23 times higher OC concentration than other cultural/ritual indoors and 9.25 times higher than residential-indoors. The highest emission factor (EF) of OC has justified the higher concentration of OC in MHS-indoors than other cultural/ritual indoors [45]. Level of
OC associated with PM2.5/PM10 in cultural/ritual indoors was approximately 2e6 times higher than the indoor temples during non peak periods and EC concentration associated with PM2.5/PM10 in cultural/ritual indoors was 1.5e4 times higher compared to temples during peak and non peak period [23].