2.1.3. Sampling SiteDescriptions ofVarious Emission Sources at
Songkhla Province. Population of Songkhla Province is about
1.32 million occupying an area of approximately 7,394 km2.
Songkhla is located 950kmsouth of Bangkok, situated on the
eastern side of theMalayan Peninsula, bordering on Nakhon
Sri Thammarat and Phatthalung to the north; Yala, Pattani,
and States of Kedah (Sai Buri) and Perlis of Malaysia to
the south; the Gulf of Thailand to the east; and Satun and
Phatthalung to the west (Figure S4). Hat-Yai, a district of
Songkhla, is better known than the provincial capital itself
as an economic and tourism zone of Songkhla and thus
many industrial factories and stores are located in this area.
Sampling site descriptions are given in detail as follows.
Prince of Songkhla University (PSU). The site was situated at
about 3mabove ground level at the Faculty of Environmental
Management of Prince of Songkhla University and about The ScientificWorld Journal 3
550m away from the main traffic road that leads to the city
center of Hat-Yai. It is important to note that PSU1 and PSU2
represent the sampling period of June (28–30 June, 2007)
and October (24–26 October, 2007), respectively.This site is
considered as an urban residential zone.
Traffic Intersection (TI). The station was located at the traffic
intersection in front of the main gate of PSU. It is situated on
the eastern side and approximately 2.5km far away fromthe
Hat-Yai city center. This station is regarded as a traffic area
close tourbanresidential zone.The air sampleswere collected
on 5–7 July, 2007.