TPS 723: Low and middle income countries: sanitation infections and other health effects, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: Due to inefficient designs and use, traditional biomass stoves emit fine particulates, and other toxics causing additional burden of diseases for a major population in developing countries. Keeping this fact in mind, this study was conducted in a few villages of Andhra Pradesh, India providing with a cost effective intervention. PM2.5 was adopted as the surrogate exposure burden and compared it's concentration with pre- and post-intervention measurements. Methods: This study was a cluster-randomized with 2 groups of 24 households each and was randomized to a traditional wood stove (control) and an efficient wood burning stove (intervention). However, the present study represents PM2.5 concentration in 24 intervention households between pre- and post-intervention periods. Area and personal measurements were done using standard protocols. Area samplings were conducted during dinner and breakfast cooking (3 hrs; N=24), non-cooking (6 hrs. after dinner and breakfast cooking; N=12) and kitchen-living room (24 hrs; N=6), whereas personal sampling with 6 participants for 3 hours during dinner cooking. Results: Pre- and post- PM2.5 concentrations (Mean ± SD) during dinner cooking periods were 376.07± 366.50 and 152.64± 106.86 µg/m3, whereas, for breakfast were 725.40±980.64 µg/m3 & 335.84±404.48 µg/m3, respectively. However, for post dinner and post breakfast non-cooking periods, concentrations were 86.54±38.71 & 55.42±37.60 µg/m3 and 116.44±68.70 & 119.30±194.76 µg/m3, respectively. Mothers and Children personal PM2.5 concentrations were 350.18±282.89 & 142.52±123.82 µg/m3 and 476.98±811.43 & 426.13±741.59 µg/m3, respectively. For 24-hours pre- & post- kitchen and living area, values were 397.71±671.04 & 114.39±134.07 µg/m3 and 157.04±235.49 & 47.35±39.91 µg/m3, respectively. Conclusion: The study showed clear reduction of PM2.5 exposure concentration in intervention period might be due to comparatively lesser amount of fuel use and higher efficiency of the improved stoves. As per users' perception, they could save some cooking time and felt better cooking environment in intervention period.