Professor David C Wilson was involved in 2004 as an advisor to the UK Delegation to the Basel Convention, and as the UK member of the expert group working on persistent organic pollutants (POPs) in wastes. More recently, he was part of the team developing guidlines on disposal for the Africa Stockpiles Programme, which aims to rid the continent of its unwanted legacy of obsolete pesticides.
The Basel expert working group was tasked with recommending both ‘low POPs contents’, above which destruction or irreversible transformation of stockpiles of the 12 POPs chemicals would be required under the Stockholm Convention, and also the levels of destruction or irreversible transformation which would need to be met. The agreed levels were adopted by the Basel Conference of Parties Conference of Parties (COP7) in October 2004 and by COP1 of Stockholm in May 2005. They also form the basis of the levels adopted in the EU’s POPs regulations.
The Africa Stockpiles Programme (ASP) is a 15 year, $250 million project to help African countries rid themselves of more than 500,000 tonnes of obsolete pesticides. The new diposal techology guidelines published in 2008 provide advice to national decision makers on how to select the most appropriate disposal technology options for their country. The guidelines were prepared for WWF by an international team led by Patrick Dyke; Professor David C Wilson provided technical review within the team. More details are provided elsewhere on this site.
DCW’s involvement in this work on POPs in wastes and on the ASP built not only on his long experience working on hazardous wastes in both developed and developing countries, but also on some more specific experience much earlier in his career (1977-1982). He was technical advisor to the Department of the Environment working group preparing guidance on pesticide wastes, including DDT and the other pesticide POPs. He was a technical advisor to the European Commission for the preparation of the so-called ‘post-Seveso’ directive to control major hazards in the chemical and other industries. He also advised directly on the decontamination of the chemical reactor at Seveso, which was responsible for dispersing the highly toxic chemical TCDD (‘dioxin’ – now defined as an unintentional POP) over the northern Italian town in an infamous industrial accident in 1996. He published several papers relating to the latter work, including one in Chemistry in Britain, ‘Lessons from Seveso’.
DCW was also responsible for the first UK guidance on contaminated land, the so-called ‘Gas Works Report’ (The Redevelopment of Gas Work and Similar Sites, first edition 1981, second edition 1987). This report for the Department of the Environment derived ‘threshold’ and ‘action’ trigger values for gas works contaminants in soil, and remained in use until 2000.
A 5-year old child with chloracne, caused by accidental exposure to TCDD (dioxin) at Seveso in 1996 (Photo kindly supplied by Dr Schulz of the Dermatological Hospital of Hamburg). TCDD is a so-called ‘unintentional POP’, i,e, a persistent organic pollutant that is formed as an accidental by-product of another process. At Seveso, it was formed in a runaway chemical reaction. More generally, it is formed in most combustion processes at very low levels. With modern emission controls on incinerators and industrial processes, accidental fires and open burning (e.g. bonfires) are becoming the main sources of atmospheric emissions.