This study aims to assess the spatial and temporal variations of size-segregated particulate matter (PM) concentration in indoor and outdoor environments located in Vellore city, India. Size-segregated PM was measured using an eight-stage cascade impactor in traffic and residential sites during monsoon, winter, and summer seasons. Results showed that bimodal and trimodal distribution were common in indoor and outdoor environments of residential and traffic sites. Average outdoor (indoor) size-segregated mass concentration in all stages varied from 5 to 38 (7 to 42) and 4 to 32 (2 to 37) μg m⁻³ in traffic and residential sites, respectively. The maximum and minimum contribution to total PM mass was observed in 9 to 10 and < 0.4 μm fractions, respectively. Indoor concentration in traffic and residential sites was highest during summer and monsoon seasons. However, outdoor concentration was observed to be maximum during summer in both sampling sites. Correlation analysis of size-segregated PM mass with wind speed and wind direction indicated the non-regional source for coarse fraction concentrations and local source for fine fraction concentrations. Further, study results showed the dominance of coarse size fractions across all seasons in both sites.

本研究旨在评估位于印度韦洛尔市的室内和室外环境中尺寸分离的颗粒物 (PM) 浓度的时空变化。在季风、冬季和夏季，在交通和住宅区使用八级级联撞击器测量了尺寸分离的 PM。结果表明，双峰和三峰分布在住宅和交通站点的室内和室外环境中很常见。所有阶段的平均室外（室内）尺寸分离质量浓度从 5 到 38（7 到 42）和 4 到 32（2 到 37）μg m ^{-3 不等}分别在交通和住宅用地。分别在 9 到 10 和 < 0.4 μm 的部分中观察到对总 PM 质量的最大和最小贡献。夏季和季风季节，交通和住宅用地的室内浓度最高。然而，观察到两个采样点的室外浓度在夏季最高。粒度分离的PM质量与风速和风向的相关性分析表明粗颗粒浓度的非区域来源和细颗粒浓度的局部来源。此外，研究结果表明，在两个地点的所有季节中，粗粒度部分都占主导地位。