Atmospheric bulk deposition of PAHs onto France: trends from urban to remote sites
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Atmospheric Environment 36 (2002) 53955403
Atmospheric bulk deposition of PAHs onto France: trendsfrom urban to remote sites
B. Garbana,*, H. Blanchouda, A. Motelay-Masseib, M. Chevreuila, D. Ollivona
aLaboratoire Hydrologie et Environnement, Ecole Pratique des Hautes Etudes, UMR Sisyphe 7619, Universit!e Pierre et Marie Curie,
4 place Jussieu, case 122, 75252 Paris cedex 05, FrancebLaboratoire de G!eologie Appliqu!ee, UMR Sisyphe 7619, Universit!e Pierre et Marie Curie, 4 place Jussieu, 75252 Paris cedex 05, France
Received 15 March 2002; received in revised form 11 June 2002; accepted 19 June 2002
Fifty-eight weekly samples of atmospheric bulk deposition (dry and wet) were collected in France at six specic sites
over a year. Urban, semi-rural, rural and forested sites were chosen on a transverse from West to East at the Paris
latitude. Seasonal variations are described, with winter time concentrations 23 times higher than summer ones due to
an increase in fossil fuel consumption in winter. When temperature did not exceed 121C, mean PAH concentrationsvaried from 221 ng l1 in Paris to 25 ng l1 at a rural site. About 50 km far from Paris, PAH concentrations decreased
by two-thirds. Urban emissions have a local impact on the fallout contamination. Fluxes at the Paris site (from
1571294 ngm2 d1) were from 2.56 times higher than in the rural and forested sites. In the latter sites, mean daily
uxes (50 ngm2 d1) were close to those of high European mountains, considered as background levels. In rural sites,
without treatment plant sludge spreading, atmospheric deposition is the major source of PAH inputs to soils.
r 2002 Elsevier Science Ltd. All rights reserved.
Keywords: PAHs; Bulk deposition; Transport; Flux; Seasonal variation
Polycyclic aromatic hydrocarbons (PAHs) are ubiqui-
tous contaminants of great environmental concern, by-
products from the incomplete combustion of fossil fuels
and wood. Forest res and volcanoes contribute to the
PAH burden. However, residential heating, coke pro-
duction, incineration and internal combustion engine
are by far major sources of PAHs (Baek et al., 1991;
Sixteen unsubstituted PAHs, some of which are
considered as being possible or probable human
carcinogens, have been listed by the US Environmental
Protection Agency (EPA) as priority pollutants. Once
they enter the atmosphere, PAHs are redistributed
between gas and particle phases and are subject to
removal mechanisms such as oxidative and photolytic
reactions and wet and dry deposition. During precipita-
tion, PAHs both in gaseous and aerosol forms are
scavenged from the atmosphere by rainwater (Ligocki
et al., 1985a, b; Dickhut and Gustafson, 1995; Hillery
et al., 1998). When deposited, they may be remobilised
and transported by air masses and winds over long
distances to settle again on land and water surfaces.
Thus, PAHs have been found in samples collected in
remote high European mountains (Steinberg et al., 1989;
Carrera et al., 2001) and in Greenland polar ice (Jaffrezo
et al., 1994; Masclet et al., 1995, 2000) or Canadian
arctic (Barrie et al., 1992; Macdonald et al., 2000).
Therefore, atmospheric transport and deposition are
important pathways of PAHs to ecosystems far from
source areas (Barrie et al., 1992) and shown by long-
range transport modelling (Mackay and Wania, 1995;
Di Toro and Hellweger, 1999; Pekar et al., 1999; Beyer
et al., 2000; Halsall et al., 2001).*Corresponding author. Fax: +33-1-44-27-51-25.
E-mail address: Brigitte.Garban@ccr.jussieu.fr (B. Garban).
1352-2310/02/$ - see front matter r 2002 Elsevier Science Ltd. All rights reserved.
PII: S 1 3 5 2 - 2 3 1 0 ( 0 2 ) 0 0 4 1 4 - 4
There is a growing concern about pollution by
persistent organic pollutants (POPs) including PAHs.
In May 2001, a global treaty for the regulation of POPs
was signed: the Stockholm Convention which in-
cludes instruments for the total elimination of 12 POPs
on a global scale. Large-scale programs are conducted in
relation to the long-range transboundary atmospheric
pollution (EMEP) or their discharge into the sea
(OSPAR). To these 12 POPs, the United Nations-
European Community added the PAHs of which
benzo(a)pyrene (BaP) is the most toxic. The objective
is to control, reduce or eliminate discharges, emissions
and losses of POPs.
In this context, knowledge on the pollution level and
its dispersion on regional and national scale is essential.
In France, PAH deposition data have been collected in
the Paris area (Ollivon et al., 1999, 2002), but no data
are available for other sites.
This study was part of the PIREN-Seine program
concerning atmospheric loading of POPs on the river
Seine catchment and their comparison with remote sites
(Brittany and Vosges forest). Our purpose was to carry
out measurements in bulk deposition (including wet and
dry deposition) in urban, rural and forested regions in
France and study the progression of the contamination
by PAHs over a WestEast transverse, then to assess
daily and annual PAH atmospheric loading.
2.1. Study area
According to the main wind directions (2202751)over France, sampling sites were set up on a transverse
from West to East and close to meteorological stations,
at Ouessant (481280N51030W), Pleumeur-Bodou(481460N31310W), Paris (481490N21290E), Coulom-miers (481500N31000E), Eclaron (481320N41450E),Abreschviller (481370N71O50E) (Fig. 1). Ouessant is asmall island (932 inhabitants) located at a few miles
from the Western point of Brittany. The rain sampler
managed by the Navy was located on the west coast in a
wild moor. The Pleumeur-Bodou rain sampler was
located in a rural area. The nearest city (18 000
inhabitants) is 6 km away. The Paris rain sampler was
located on the roof of a Paris university (Universit!e
Pierre et Marie Curie), 25m above street level (Paris and
suburbs population adds up to 11 millions inhabitants).
The Coulommiers rain sampler was located in a
suburban agricultural (rurban) village close to Cou-
lommiers (14 000 inhabitants), 10 km away. The
Eclaron rain sampler was situated in a rural region;
the nearest city (33 500 inhabitants) is 40 km away to the
Northeast. The collection site in Abreschviller (1300
inhabitants) was in the Donon Massif (Vosges forest).
All the sites were located in open areas, out of vegetation
Samples were collected weekly from 17 October 1999
to 26 December 1999, and from 20 March 2000 to 10
October 2000 for all sites, except at Eclaron where
sampling began in March 2000. No snowfall occurred
during the overall sampling periods. The bulk atmo-
spheric deposition (wet and dry) were collected using
open pyramidal stainless steel funnels with a 0.36m2
collection area, collecting up to 70mm of rain without
overow in a 25 l aluminium tank. The collectors receive
both wet and dry deposition. All apparatus and
containers were previously washed with Milli-Q water,
then with HPLC quality grade acetone and hexane.
Samples were mailed by express package within 2 days
to the laboratory. Once in the laboratory, samples are
stored at 41C in darkness and extracted within 48 h, thenthe extract was stored at 41C until analysis.
2.2. Meteorological conditions
Precipitation amounts, wind direction, and tempera-
ture were obtained from Meteo France. At Paris, there
were 175 rainy days during the study corresponding to a
precipitation height of 825mm. At Abreschviller, annual
precipitation height from 17 October 1999 to 08 October
2000 was 1590mm (about twice higher than elsewhere:
Ouessant 907mm; Pleumeur-Bodou 979mm; Coulom-
miers 828mm). Considering only the sampling weeks,
mean daily local temperatures ranged from 7.41C to12.81C at Ouessant, 7.113.41C at Pleumeur-Bodou,8.219.71C at Paris, 6.4171C at Coulommiers, 7.418.91C at Eclaron and 2.216.61C at Abreschviller. Theprevailing winds were westerly and southwesterly as
shown in Fig. 1 where annual wind roses are displayed
for three sites.
2.3. Analytical procedure
Raw samples including wet and dry deposition were
extracted using a liquidliquid technique. Samples were
shaken 3 times for 20min in a glass bottle, using 100ml
of a hexane/methylene chloride mixture (v/v 85/15) for
each litre of sample (Ollivon et al., 1999). Extracts were
combined and reduced to 3ml on a rotary evaporator;
after removal of sulphides by adding mercury, no
further purication was performed. As the elution
solvent for HPLC is acetonitrile/water, hexane had to
be exchanged to acetonitrile. For doing so, methylene
chloride and acetonitrile were added to the reduced
extract in a 3/1/1 proportion for hexane/methylene
chloride/acetonitrile, respectively. Then the mixture was
concentrated to about 0.5ml and subjected to liquid
The identity of each PAH was conrmed by the use of
a standard mixture (PAH-Mix 9 in acetonitrile from
B. Garban et al. / Atmospheric Environment 36 (2002) 539554035396
Dr Ehrenstorfer GmbH, Augsburg, Germany) contain-
ing the 16 PAHs recommended by the EPA method No.
610: naphthalene (NAP), acenap