Department of Chemistry, Dr B.R. Ambedkar University, Agra, 282002, India.
Centre of Atmospheric Science, Indian Institute of Technology Delhi, New Delhi, 110016, India.
Chemosphere. 2020 Jun;249:126140. doi: 10.1016/j.chemosphere.2020.126140. Epub 2020 Feb 7.
Presented here are size-resolved aerosol measurements conducted using cascade impactor set at breathing zone in indoor-outdoor residential microenvironments. PM contributed about 64-80% of PM in which over 29% of mass was shared by PM Total PM concentration varied from 261 ± 22 μg/m (indoors) to 256 ± 64 μg/m (outdoors) annually; whilst summer and monsoon demonstrated 1.2- and 1.9- times lower concentration than winters. The measured metals ranged between 9% (in PM) to 18% (in PM) of aerosol concentration; whereby crustal elements dominated coarse fractions with relatively higher proportion of toxic elements (Ba, Cd, Co, Cr, Cu, Ni) in ultrafine range. Considering lognormal particle size distribution (PSD), accumulation mode represented the main surface area during entire monitoring period (Mass Median Aerodynamic Diameter (MMAD) < 1). PSD of metal species reflected their different emission sources with respect to season integrated samples. High air exchange conditions permitted the shift of indoor PSD pattern closer to that of outdoor air while low ventilation in winters reflected modal shift of metals (Pb, Mg. K) towards larger size particles. Relative surge towards smaller diameter size of soluble metal fraction relative to the total concentration of toxic elements was noted on an annual basis with high infiltration capacity of smaller size particulates (Finf =1.36 for ultrafine particles in summers) identified through indoor-outdoor regression analysis. Principal Component Analysis identified sources such as vehicular traffic, combustion, crustal emission with activities viz. smoking and those involving use of electric appliances.
这里呈现的是在室内-室外住宅微环境中使用在呼吸区设置的级联冲击器进行的按尺寸分辨的气溶胶测量。颗粒物占颗粒物总量的 64-80%，其中超过 29%的质量由总颗粒物分担。总颗粒物浓度每年变化范围为 261±22μg/m（室内）至 256±64μg/m（室外）；而夏季和季风季节的浓度比冬季低 1.2-1.9 倍。所测量的金属浓度在气溶胶浓度的 9%（在颗粒物中）到 18%（在细颗粒物中）之间；其中地壳元素在粗颗粒中占主导地位，而在超细颗粒中则含有相对较高比例的有毒元素（钡、镉、钴、铬、铜、镍）。考虑到对数正态颗粒尺寸分布（PSD），在整个监测期间，积聚模态代表了主要的表面积（质量中值空气动力学直径（MMAD）<1）。金属物种的 PSD 反映了它们在不同季节综合样本中的不同排放源。高空气交换条件允许室内 PSD 模式向室外空气模式靠拢，而冬季通风不良则反映出金属（铅、镁、钾）的模态向较大粒径颗粒的转移。在每年的基础上，可溶性金属部分相对于有毒元素的总浓度向更小粒径的相对跃升，这与较小粒径颗粒的高渗透能力有关（夏季超细颗粒的 Finf=1.36），这是通过室内-室外回归分析确定的。主成分分析确定了车辆交通、燃烧、地壳排放等来源，以及吸烟和使用电器等活动。
