Author/Authors :
mohammed, mohammed o.a. university of khartoum - faculty of public and environmental health, Khartoum, Sudan , mohammed, mohammed o.a. harbin institute of technology - international joint research center for persistent toxic substances (ijrc-pts), school of municipal and environmental engineering - state key laboratory of urban water resource and environment, Harbin, China , song, wei-wei harbin institute of technology - international joint research center for persistent toxic substances (ijrc-pts), school of municipal and environmental engineering - state key laboratory of urban water resource and environment, Harbin, China , li, yi-fan harbin institute of technology - international joint research center for persistent toxic substances (ijrc-pts), school of municipal and environmental engineering - state key laboratory of urban water resource and environment, Harbin, China , elzaki, ahmed a. university of khartoum - faculty of public and environmental health, Khartoum, Sudan , ibrahim, mohammed a.e.m. university of khartoum - faculty of public and environmental health, Khartoum, Sudan , ahmed, alshebli a. university of khartoum - faculty of public and environmental health, Khartoum, Sudan , sabil, eithar e.e. university of khartoum - faculty of public and environmental health, Khartoum, Sudan
Abstract :
Investigation of indoor/outdoor (I/O) relations of PM2.5, is considered essential since people spend approximately 90% of their time indoors, with great segment of indoor pollution being originated outdoors. Using PM2.5 I/O ratios, and infiltration factors, the PM2.5 I/O relations are firstly estimated. Thereafter, analysis with Non-metric Multi Dimensional Scaling (NMDS) and Partial Least Square(PLS) regression was performed to pinpoint the consistency of results obtained by the different methods. PM2.5 mass levels showed spatial homogeneity across the sampling sites, which is attributed to absence of cooking, indoor smoking, and natural ventilation. For wintertime, while NMDS showed distinct clusters of source tracers, an advanced PLS regression revealed overlapping of coal combustion related species with traffic markers between indoor and outdoor. For summertime, NMDS showed that, coal related tracers were split up into sub clusters suggesting contribution from factories besides winter-heating, and that, the distances between the same markers for outdoors and indoors were closer than that for wintertime. It is also suggested that, SO4 ^2- and NO3^- were not influenced by the same factors/sources.
Keywords :
PM2.5 , Partial Least Square regressionSeed oil , indoor , outdoor relationships , Non , metric Multi Dimensional Scaling
