The report found that, even taking into account the highest concentrations of dioxins measured in the soils, exposure of individuals was well within the Tolerable Daily Intake (TDI) for these substances as advised by the UK's Committee on the Toxicity of Chemicals in Food, Consumer Products and the Environment (COT).
Scientists compiled the report after taking a total of 51 soil samples from farmland adjacent to the incinerators at Otterbourne, Marchwood, Havant and Chineham. They concluded that the levels of dioxins in the soils were as expected in view of the urban and industrial activity to which the soils had been exposed, and were within the range found in other similar areas of the country.
Some samples taken near to the Otterbourne incinerator showed dioxin levels which were at the higher end of the range for urban soils, but which still equated to exposure levels well within the TDI. Scientists concluded that even using extreme assumptions - for example if a person consumed all his/her root vegetable intake from this single, high-concentration source - the resulting exposure to dioxins would be equivalent to approximately one third of the TDI.
The first report was published in 1989 and contained information about dioxin in soils throughout the UK. The second report, published in December 1995, contained information on dioxins in the soil adjacent to the incinerator at Otterbourne, but no data about soils adjacent to the other Hampshire incinerators. In addition, HMIP published two other reports on dioxins - 'A review of dioxin emission in the UK' (1995) and 'Risk assessment of dioxin releases from municipal waste incineration processes' (1996).
The latest report has been sent to local MPs, local authorities, local environmental interest groups and representatives of local residents.
The incinerators at Otterbourne, Marchwood, Havant and Chineham ceased operating at the end of November 1996 when stringent new emission standards for municipal waste incinerators were introduced by the Environment Agency.