Are reductions in environmental burdens of industrial organic contaminants in rich countries achieved partly by export of toxic waste?

The key hypothesis behind this project is a potential global scale transition of major source regions of industrial organic contaminants associated with electrical and electronic products; From former regions of production and use, towards regions implicated as recipients of obsolete products and wastes, such as Southeast Asia and West Africa. The project has facilitated extensive internal collaboration with researchers from China, Bangladesh, India, Pakistan, Nepal, Canada, UK and some West African countries. Measurements of selected industrial organic contaminants in the atmosphere at Cape Verde, combining targeted sampling and model analysis, have been carried out to monitor the possible outflow from the West African continent. A general finding is that concentrations in air at Cape Verde are in the lower range, compared to other areas. Collaborative research efforts with scientists in West Africa and UK have also been undertaken to measure industrial organic contaminants at a major informal e-waste recycling site in Ghana (Agbogbloshie) and a dump site outside Kington, Sierra Leone. A general finding is that concentrations in soils were high with frequent exceedances of guideline values, which may represent a possible risk. Ship graveyards are hypothesized as being another potential source of industrial organic contaminants in developing regions. One of the larger ship graveyards is found in Chittagong, Bangladesh. The project has carried out a sampling campaign using passive air samplers around this ship breaking area, along with additional sites in the city. Estimated toxic equivalent quotients indicate elevated human health risks caused by inhalation of PAHs at most sites, and chemical fingerprinting techniques point towards combustion processes in the vicinity of ship breaking activities as a major source. Facilitated by our contacts at Lancaster University and the Chinese Academy of Sciences (CAS), we have been introduced to scientists from China, Pakistan, India and Nepal for whom the project has collaborated afterwards. As a direct outcome of discussions after an invited guest lecture held at CAS in 2014, we have published a joint review article discussing the status and knowledge concerning e-waste in Pakistan in 2015. This study has been followed by several field studies at both informal e-waste areas in Karachi and other cities within Pakistan, as well as urban areas of Nepal. We have also expanded on the collaboration with scientists in India. Their main interest is on tracking major sources and source regions of PCBs, which are toxic legacy contaminants mainly used in electrical equipment. E-waste, ship-breaking activities and dumped solid waste were implicated as likely sources of PCBs on the basis of air measurements, and a follow-up study discusses their occurrence in soils across India. The project has also addressed, and quantified, global flows of e-waste from OECD countries towards developing regions. A follow-up study discusses potential implications of such flows for emissions, environmental transport, distribution and trends of industrial organic contaminants at a global scale. Towards the end of the project, a specific focus has been on global mass flows of selected brominated flame retardants (PBDEs) along with potential consequences for global emissions, occurrence and regulations of such substances. We have also carried out studies to better understand and predict human exposure to industrial organic contaminants in the context of spatially and temporally variable emissions. A general finding is that such emission trends largely dictate underlying trends in human exposures. In collaboration with Chinese and UK scientists, we have studied how temporally variable emissions of PCBs in China may influence human exposure. These results suggest not only production, use and recycling/disposal of associated products dictates human exposures as a function of time, but are additionally influenced by temporal changes in the Chinese diet. In conclusion, our studies show that industrial organic contaminants are not only transported on a global scale by environmental long-range transport, but also embedded in products and wastes - and as contaminants in food. A better understanding of contaminant cycles across societies and ecosystems is relevant for more holistic chemical management strategies, aiming to protect and minimize further environmental and human exposures from harmful substances.

-

Rich, industrialized countries have been perceived as the major source regions of toxic industrial organic contaminants, such as polychlorinated biphenyls (PCBs) and various halogenated flame retardants (HFRs). Only these countries were in the position to produce and benefit from extensive use of these chemicals for various applications and consumer goods until regulated, following increasing recognition of their environmental and human health risks. While significant reductions in environmental burdens are now typically observed in Europe and North America, a number of recent studies document that surprisingly high levels of these industrial chemicals still persist outside industrialized use regions, such as parts of Africa and Asia. These are regions which are typically implicated as recipients of various obsolete products and wastes containing these toxic chemicals. This led us to raise the question whether reductions in environmental burdens in rich countries are achieved partly by uncontrolled export of toxic wastes, rather than environmental stewardship through regular emission reductions? In this project, we propose to carry out case studies in West Africa and Asia where particularly high air concentrations have been reported, yet where the key sources of these toxic chemicals remains to be identified. Using a combination of environmental measurements and modeling, we aim to track and identify the major sources and source regions of PCBs and selected HFRs in these areas. In parallel, the global scale implications of emissions associated with trans-boundary movements of wastes will be studied, using PCBs and selected HFRs as examples. As the potential for detrimental effects on the environment and human health due to long-range transport by air, water, or wastes probably should be of equal concern when managing and regulating industrial organic contaminants, the key implications for regional and global control strategies will be analyzed and discussed and main results communicated.