Official estimates of the number of premature deaths and hospital admissions caused by incinerator emissions of nitrogen oxides have been slashed by two orders of magnitude following the discovery of an error in a consultancy report, according to Environment Minister Michael Meacher. 1
The impact of NOx emissions on health was brought into the spotlight by Greenpeace's recent occupation of London Waste's municipal waste incinerator in Edmonton, north London (ENDS Report 309, pp 22-24 ).
Using Department of Health figures, the group calculated that, at 0.02 deaths per year per tonne of NOx, the plant's current emissions bring forward 15 deaths per year - and its proposed expansion would add another seven.
The issue was also studied by consultancy Entec in a cost/benefit assessment of the proposed EC Directive on waste incineration for the Department of the Environment, Transport and the Regions. The study was under fire earlier this year for estimating that there are only 60 on-farm incinerators in the UK when the true figure is 2,000-3,000 (ENDS Report 306, pp 37-38 ).
Using Department of Health data, Entec concluded that the proposed NOx limit in the Directive would prevent 46 deaths and 91 respiratory hospital admissions being brought forward as a result of ozone formation.
According to Mr Meacher, Entec "very recently recognised a mathematical error" in these calculations. The correct figures, he said, are 0.7 deaths and 0.9 hospital admissions not brought forward. The Minister omitted to say what impact these changes would have on the estimated benefits of the Directive.
Mr Meacher also provided projections of NOx emissions from three types of incinerators over the next 20 years which showed that they currently account for 0.3% of the UK's total emissions, with the figure rising to 2.0% by 2010 as emissions from other sources decline (see table
The projections are based on unspecified "assumptions about changes in capacity", and do not take account of the NOx limits in the new Directive. Intriguingly, they hint at a four-fold expansion in municipal waste incineration capacity by 2010.