Environmental Engineering Reference
In-Depth Information
Sampling and Methods
Five PM
2.5
(particulate matter £2.5 mm) sampling sites were positioned along a
transect from NW to SE through the city of Beijing (Fig.
1
). Sampling was carried
out with mini-volume-samplers at a flow rate of 200 L/h separately for day and night
on a weekly basis. Day-time samples were taken from 7 a.m. to 7 p.m. and night-
time samples from 7 p.m. to 7 a.m., respectively. Site 1, 4 and 5 were installed at 1.5 m
above ground - a height especially relevant for the exposure to humans. Site 2 and
3 were set up on building roofs at heights of about 20 and 7 m, respectively.
At site 4 TSP samples (total suspended particles £100 mm) were taken additionally
with a TSP-Sampler at a flow rate of 1 m
3
/h. TSP samples were also collected weekly,
but without distinction between day and night. All samples were collected on quartz
fiber filters (MN QF 10, Macherey-Nagel, d = 50 mm). The sampling period
presented within this paper comprises 1 year, from January to December 2006.
Fig. 1
City map of Beijing with the locations of the five sampling sites (from beijing2008.
go2map.com)
