PMID- 19245015
OWN - NLM
STAT- MEDLINE
DCOM- 20090330
LR  - 20190715
IS  - 0013-936X (Print)
IS  - 0013-936X (Linking)
VI  - 43
IP  - 3
DP  - 2009 Feb 1
TI  - Measuring and modeling short-term variability of PCBs in air and characterization 
      of urban source strength in Zurich, Switzerland.
PG  - 769-76
AB  - Diel (24-h) variations of concentrations of polychlorinated biphenyls (PCBs) in 
      air are reported at two sites in Zurich, Switzerland, a city surrounded by hills. 
      One site was located in the valley near the city center and the other site was on 
      a hill called Uetliberg, 411 m higher and about 5 km distant from the city center 
      site. Air samples were collected simultaneously at both sites over 4-h time 
      periods for 3 consecutive days under stable meteorological conditions during a 
      high pressure system in August 2007. PCB concentrations at the city site were 
      markedly higher than those at Uetliberg, indicating that the city site is 
      influenced by urban sources of PCBs. Concentrations measured at both sites show a 
      clear diel cycle but have opposite phases: in the city concentrations were lower 
      during the day and higher at night, while at Uetliberg concentrations were higher 
      during the day and lower at night. These observations are explained and 
      interpreted using a multimedia mass balance model that includes a stable 
      night-time inversion layer that formed over the city but below the hilltop site. 
      At Uetliberg the concentration of PCBs is consistent with background levels and 
      the diel concentration pattern can be explained bytemperature-mediated 
      air-surface exchange and the influence of nearby woodland canopies. The diel 
      pattern and concentrations in the city are attributable to volatilization from 
      urban sources. We have developed a new method to estimate the strength of the 
      urban PCB source using the model scenarios for the two sampling sites. Emission 
      estimates derived from this method are in good agreement with earlier estimates 
      derived from PCB production, consumption, and usage estimates. This study 
      demonstrates the potential for estimating the strength of diffuse, regional 
      sources of persistent organic pollutants (POPs) using a combined measurement and 
      modeling approach. Such studies can provide important information to derive 
      regional and national POPs emission inventories as required under the Stockholm 
      Convention, and to quantify the effectiveness of actions to reduce POP emissions.
FAU - Gasic, Bojan
AU  - Gasic B
AD  - Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, 
      Switzerland.
FAU - Moeckel, Claudia
AU  - Moeckel C
FAU - MacLeod, Matthew
AU  - MacLeod M
FAU - Brunner, Jurg
AU  - Brunner J
FAU - Scheringer, Martin
AU  - Scheringer M
FAU - Jones, Kevin C
AU  - Jones KC
FAU - Hungerbuhler, Konrad
AU  - Hungerbuhler K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Environ Sci Technol
JT  - Environmental science & technology
JID - 0213155
RN  - 0 (Air Pollutants)
SB  - IM
MH  - Air Pollutants/*analysis
MH  - *Models, Theoretical
MH  - Quality Control
MH  - Switzerland
EDAT- 2009/02/28 09:00
MHDA- 2009/03/31 09:00
CRDT- 2009/02/28 09:00
PHST- 2009/02/28 09:00 [entrez]
PHST- 2009/02/28 09:00 [pubmed]
PHST- 2009/03/31 09:00 [medline]
AID - 10.1021/es8023435 [doi]
PST - ppublish
SO  - Environ Sci Technol. 2009 Feb 1;43(3):769-76. doi: 10.1021/es8023435.