id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
cord-339475-okw6la2b	nan	Chapter 11 Health effects	2005-12-31		.txt	text/plain	3091	173	44	However, none of the harmful components mentioned above exists in ambient particles at sufficiently high concentration levels to cause a specific disease. Ambient particles are harmful when their concentration exceeds a certain limit; epidemiological studies have indicated a strong association of increases in human morbidity and mortality rates with increased concentrations of ambient particles in a certain size fraction (Wilson and Spengler, 1996; Vedal, 1997) .	cache/cord-339475-okw6la2b.txt	txt/cord-339475-okw6la2b.txt
