Environ. Sci. Technol. 2004, 38, 699-706
PBDEs in the Atmosphere of Three Locations in Western Europe ROBERT G. M. LEE,* GARETH O. THOMAS, AND KEVIN C. JONES Department of Environmental Science, Institute of Environmental and Natural Sciences, Lancaster University, Lancaster, LA1 4YQ, UK
Atmospheric concentrations of PBDEs (108 samples in total) were measured at 2 rural/semirural sites in England and 1 remote site on the west coast of Ireland in the years 2001 and 2000, respectively. Detailed analysis of the factors affecting concentrations is performed. The United Kingdom (UK) has been a major producer and user of PBDEs. Concentrations of ΣPBDEs at Mace Head (MH), Ireland ranged between 0.22 and 5.0 pg m-3 with a mean of 2.6 pg m-3 and were controlled primarily by advection. ΣPBDEs concentrations at Hazelrigg (HR), northwest England, ranged between 2.8 and 37 pg m-3 with a mean of 12 pg m-3 and at Chilton (CH), southwest England between 3.4 and 33 pg m-3 with a mean of 11 pg m-3. The average mixture of PBDEs in air was similar to that of commercial penta-BDE products. Movement of air over local/regional sources influenced concentrations of PBDEs at all sites, particularly at MH. At the two English sites during the summer, concentrations of PBDEs were strongly influenced by temperature, indicating that airsurface exchange processes play an important role. Advection became more influential during winter, particularly at CH, where a different congener profile was observed in some samples as ambient air temperatures decreased and PBDE concentrations increased. It is hypothesized that this was due to increased emissions from diffuse combustion sources.
Introduction Polybrominated diphenyl ethers (PBDEs) are a group of flame retardants that are recognized as ubiquitous environmental pollutants (1, 2). They have been identified in a range of environmental media from around the world (3-7), in human tissues (8, 9), and may induce certain toxicological effects (1). PBDEs have physicochemical properties similar to a number of other persistent organic pollutants (POPs), which are known to persist and bioaccumulate in the environment. Three PBDE technical mixtures (penta-BDE, octa-BDE, and deca-BDE) have been or are used in a range of different applications and commercial products. Worldwide demand for PBDEs in 1999 was approximately 70 000 tonnes, with deca-BDE accounting for ∼56 000 and penta-BDE ∼8500 tonnes. Penta-, octa-, and deca-BDE usage in Europe was estimated to be 150, 400, and 7000 tonnes, respectively, at this time (1). There has been a growing concern over the persistence and presence of PBDEs in biota, leading to industry voluntarily replacing the lower brominated products * Corresponding author phone: (+44 1524) 592578; fax: (+44 1524) 593985; e-mail:
[email protected]. 10.1021/es035042c CCC: $27.50 Published on Web 12/30/2003
2004 American Chemical Society
with other flame retardants in some countries. The pentaBDE is in the process of being banned in the UK and Europe, although there are no voluntary or regulatory restrictions on the use of octa- and deca-BDEs in Europe at present. The UK is one of a few countries where fire regulations specify the use of flame-retardants in a range of domestic consumer products. PBDEs and other flame-retardants are therefore present in a wide range of domestic and office furniture/appliances. Degassing of PBDEs from domestic/ office products and their eventual mode of disposal can create a number of routes through which PBDEs can enter the general environment and lead to human exposure. PBDEs, like other semivolatile organic compounds, partition between the vapor and particulate phases in air, and are likely to undergo air-surface exchange and long-range atmospheric transport (LRAT) (10, 11). The atmosphere is therefore a potentially important means of exposure to and movement of PBDEs and other flame-retardants. However there is still a paucity of atmospheric concentration data for PBDEs. This study was therefore conducted, with the aim of establishing the following: background concentrations of PBDEs in the British Isles; concentrations in the atmosphere of a potential source country (UK); the spatial variations in concentrations; and some of the factors that control ambient PBDE concentrations. This builds on a number of similar studies which have been carried out on other POPs in the UK atmosphere (12-16).
Methods Sampling Sites. Mace Head (MH) is an atmospheric research station on the west coast of Ireland (53°20′ N, 9°54′ W) operated by the Department of Physics at the National University of Ireland, Galway. It is a European background/ remote site, ca. 50 m from the Atlantic Ocean. To the north, south, and east, the countryside is mostly rural. The nearest major town is Galway, about 55 km away. The majority of the air systems that affect the site approach from the west and are influenced by the maritime environment. Occasionally air masses approach from the east, which have travelled over eastern Ireland, the UK, and/or mainland Europe. Hazelrigg (HR) is a field station belonging to Lancaster University (54°2′ N, 2°45′ W), situated on the northwest coast of England in a semirural area outside Lancaster, a town of ca. 70 000 inhabitants. The site is approximately 5 km from the Irish Sea. Much of the land within 50 km of the site is rural, the Lake District and Yorkshire Dales National Parks, and Pennines. However, a number of towns and cities are also within the area. The weather at the site is dominated by low pressure systems from the west, which typically approach from 180° to 360° (S, SW, W, N); often these systems have had little contact with land. Occasionally high pressure systems remain over the UK and provide periods of relatively stable atmospheric conditions when air systems may approach from 0° to 180° (N, E, SE, S); these weather systems will have passed over inland areas of the UK and on some occasions parts of Europe. Chilton (CH) (51°40′ N, 1°20′ W) is situated ∼20 km south of Oxford and ∼70 km west of London. The site is ∼120 km inland, with numerous villages, towns, and urban areas, within a 100 km radius. The site is affected more by weather systems approaching from the SW, with more southerly origins than at MH and HR. Air masses that affect CH have moved over at least 100 km of land, in some of the most populated (southern and central) parts of England. CH can therefore be influenced by urban and industrial inland areas of the UK and can be classed as a semirural inland site. VOL. 38, NO. 3, 2004 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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TABLE 1. Concentrations of PBDEs at Hazelrigg, Chilton, and Mace Head (pg m-3)a Hazelrigg
Chilton
Mace Head
PBDE
mean
max.
min.
mean
max.
min.
mean
max.
min.
17 28 32 35 37 47 49 66 71 75 77 85 99 100 119 138 153 154 166 181 190 ΣPBDE
0.20 0.49 0.21 0.29 1.0 5.2 0.41 0.30 0.37
