Persistent organic pollutants workshop

The aims of this workshop were to review current scientific knowledge about POPs and, within the context of society’s perception of the risk and the value judgements involved, to identify the research priorities and appropriate management tools for guiding policy-makers.

A workshop entitled Controlling Persistent Organic Pollutants – What next? was organised by SEI and ETAF (European Training and Assessment Foundation) in York, (U.K.), 5th - 8th May, 1998 and funded by ETAF.

The workshop working paper was prepared by Harry Vallack (Stockholm Environment Institute) who subsequently incorporated the agreed changes, including additional material presented at the workshop, into the final version of the paper which has now been published as an assessment report in Environmental Toxicology and Pharmacology, Vol. 6 (1998) 143-175.

Global POP Migration processes
Figure 1. Global Pop Migration Processes

Persistent organic pollutants (POPs) form a class of persistent, bioaccumulative chemical substances which can result in adverse effects to human health and the environment at locations both near and far from their sources.

In addition to the adverse acute effects that can result from accidental exposure or ingestion, there are also various chronic effects that can result from long-term, low -level exposure.

These chronic effects include the promotion of cancers, damage to the central and peripheral nervous systems, reproductive disorders, disruption of the immune system and interference with normal infant and child development. Some are also thought to be endocrine disrupters which, by altering the hormone system, can damage reproductive and immune systems of both exposed individuals and their offspring.

Figure 2. Prop. general chemical risk assessment scheme

Because they tend to be highly mobile in the environment as well as being resistant to degradation processes, POPs are prone to long-range transport and can accumulate in remote regions where they have never been used.

It is now widely accepted that the use of such substances cannot be considered a sustainable practice and that concerted action needs to be taken to protect future generations.

To this end, under the auspices of the UN-ECE Convention on Long Range Transboundary Air Pollution (CLRTAP), which encompasses Europe and North America, a POPs protocol has been agreed and is due to be ratified in 1999.

Also, because of the global nature of the risk, UNEP have initiated negotiations on an international legally-binding instrument for implementing international action on POPs. Under this global process, the twelve POPs being considered initially are PCBs, dioxins, furans, aldrin, dieldrin, DDT, endrin, chlordane, hexachlorobenzene, mirex, toxaphene and heptachlor.

Vallack, H.W., Bakker, D.J., Brandt, I, Broström-Lundén, E., Brouwer A., Bull, K.R., Gough, C., Guardans, R., Holoubek, I., Jansson, B., Koch, K., Kuylenstierna, J., Lecloux, A., Mackay, D., McCutcheon, P., Mocarelli, P., Scheidegger, N.M.I., Sunden-Bylehn, A. and Taalman, R.D.F. (1998) Controlling persistent organic pollutants - What next? Environmental Toxicology and Pharmacology 6, 143-175.