id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
cet-15611		cet-15611		6	.pdf	application/pdf	3541	169	50	Indoor PM 2.5 levels may derive from emissions of indoor PM 2.5 sources and emissions from outdoor PM 2.5 sources. This observation is also demonstrated by Gupta and Elumalai (2019), where PM levels can be 1.8 to 6.7 times higher near roadways during peak traffic compared to outdoor levels.	cache/cet-15611.pdf	txt/cet-15611.txt