id	keyword
ap-4179	pahs
ap-4179	concentration
ap-4179	height
ap-4179	filters
ap-4179	sampling
ap-4179	loq
ap-4179	period
ap-4179	air
ap-4179	monitoring
ap-4179	ozone
ap-4179	hydrocarbons
ap-4179	tower
ap-4179	polycyclic
ap-4179	figure
ap-4179	atmospheric
ap-4179	analyser
ap-4179	doi:10.1016
ap-4179	urban