12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Continuous Monitoring of PCDD/Fs in the UK Atmo...
View graph of relations

« Back

Continuous Monitoring of PCDD/Fs in the UK Atmosphere : 1991-2008.

Research output: Contribution to journalJournal article

Published

Journal publication date1/08/2010
JournalEnvironmental Science and Technology
Journal number15
Volume44
Number of pages6
Pages5735-5740
Original languageEnglish

Abstract

This study summarizes the key findings of a long-term (1991−2008) monitoring program to measure polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in urban and rural ambient air in the UK. Air concentrations are reported for 6 sites—3 urban (London, Manchester, and Middlesbrough) and 3 rural/semirural (Hazelrigg, High Muffles, and Stoke Ferry). Nearly 310 samples have been analyzed, each for a 3-month period. Annually averaged urban concentrations in the early 1990s were typically a few 100s fg (TEQ) m−3 and <50 fg m−3 in the mid-2000s. Applying first-order kinetics to the whole urban time series gave T1/2 (atmospheric half-lives) in London and Manchester of 3.2−5.9 and 4.1−5.9 years, respectively. Estimated national annual atmospheric emissions trends broadly correlated with the trends in urban ambient concentrations, suggesting that the inventory has captured the broad mixture of sources. However, rural air concentrations (in the low 10s fg m−3) show no discernible change since 1996, while recent urban concentrations are close to those in rural areas. Other UK trend data infer the declines in the 1990s followed previous declines in the 1980s from peak levels in the 1950−1970s, all before routine monitoring began. Winter concentrations are generally a factor of 2−3 higher than summer concentrations, implicating diffuse combustion sources (e.g., domestic space heating). These observations taken together suggest that most major readily controllable primary/point sources were reduced by the early/mid-1990s in the UK and that current ambient levels in both rural and urban areas may remain at broadly similar levels in the foreseeable future, unless there are major changes in energy requirements and generation options, fuel usage, and policy drivers.