Lancaster University, UK

Prof Kevin Jones is Distinguished Professor at Lancaster University, UK and former Director of the Lancaster Environment Centre (LCE). LEC is a multi-disciplinary centre, with over 500 environmental professionals on site,...

an amalgamation of academics, government scientists, businesses and regulators. The Centre, one of the largest in the world, has nearly 1000 undergraduates and 300 postgraduates. Kevin's research interests focus on the environmental sources, fate, behavior and effects of persistent organic pollutants (POPs). He collaborates with many groups internationally, particularly in China, other parts of Asia and Africa. He works closely with academics, industry and government. He has published over 600 papers and enjoyed supervising nearly 100 PhD students.

 

Abstract


POPs – A STORY OF GLOBAL SCALE POLLUTANTS

Kevin C Jones1, *

1 Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK

In this presentation, we will look at the global scale sources, fate, behaviour and processes governing persistent organic pollutants (POPs). I will set the context by reviewing some of the historical background to how and why we became interested in POPs at the regional and global scale, and why it is important in an international context. I will discuss some of the key scientific concepts and their significance, such as long-range transport, cold condensation, and global fractionation, together with global mass balances, primary and secondary sources, and the scientific challenges of investigating them. I will advocate a ‘whole system’ approach to studying POPs, and the benefits of combining source estimation, lab studies, field measurement campaigns and modelling. This journey will take us from some of the early studies on POPs in the 1960s and 1970s, up to present day questions and priorities.

A main driver here was that long-range atmospheric transport could lead to accumulation and effects of POPs far from sources. This requires an ‘holistic approach’ to quantifying source-pathway-receptor processes which then became scaled-up to examine the local, regional and global scale distribution of POPs, and to look for field evidence of global fractionation and cold condensation. This relied on the ability to look for POPs ‘wherever they go’ – in air, soils, vegetation, freshwater and marine systems. This needed dedicated clean room and ultra-trace analysis tools, together with passive air and water sampling techniques, that made it possible to sample across large regions of the world at several sites simultaneously. The Stockholm Convention requires countries to conduct source inventories and to obtain spatial and temporal trend data; the timely work with passive sampling made it possible to start to assemble regional and global scale databases, and to assemble global, regional and national source and emission inventory data, together with time trend data, and to scrutinise this with multi-media fate models. This approach – global chemical mass balances and accounting – is now fundamental to underpinning chemicals regulations. A key scientific issue to emerge from this early work was whether ambient levels and exposures to POPs which had been or were about to be regulated were controlled by primary (ongoing, ‘fresh’) sources or secondary (previously emitted compound re-cycling through the environment). This required the search for evidence, via trend analysis, short-term flux measurements, the use of chiral compounds and so on, to quantify the relative importance of sources and processes. This was key to inform decision-makers, who were being challenged – ‘is there more we can do to control these compounds?; is the Stockholm Convention working?’ An approach utilised here was to study archived samples, to look back in time, at pre-industrial and pre-regulation levels.

An early ‘missing piece’ in the early understanding of POPs transfers and exposures was the role of plants (grasslands; forested systems; marine phytoplankton), in facilitating air-surface exchange, and ‘draw-down’ into soils and marine systems. There has been important work to quantify these processes and shed light on their role in transferring, assimilating and degrading such compounds. Diverse systems in the tropics, temperate and polar systems have now all been studied. This research has highlighted the dynamic controls and buffering capacities of natural systems for pollutants.

Finally, China, India and some developing countries now provide some of the most important challenges for environmental monitoring and chemicals management, with issues such as e-waste export and disposal, excessive use of pesticides and antibiotics, and where water, air and soils quality are now a critical focus.