But at the same time question marks were raised over another waste management option – composting in windrows. Scientific experts sitting with Mr Morley at the launch of the health study agreed that there were concerns raised in the study over health hazards that can arise from composting.
Mr Morley explained that the study, which runs to 400 pages and is several months late in publication, is “a combination of existing studies and an analysis of that.” The study, he said, provides “reassurance for local authorities particularly those that are looking to divert material from landfill.”
Worse option
Reminding his audience that in all waste disposal options there is a risk but this needs to be put into proportion. He put landfill clearly as a “worse option than incineration”, although he said it was up to local authorities to devise policies for their own areas. He said: “This is not a clear steer on incineration but it does put incineration as an option into perspective. It had been seen that this is worse than landfill and the study shows it is no worse than landfill at the very least.”
Tackled further on incineration, Mr Morley said: “In the range of options there is no reason, more or less, why local authorities should not opt for incineration with energy recovery. It is above landfill in the hierarchy.” His view was endorsed by Professor Howard Dalton, chief scientific adviser at the Department for Environment, Food and Rural Affairs. Professor Dalton emphasised that landfill creates 27% of the UK's methane gas emissions and “we have signed up to reduce this”.
Compost
Mr Morley was tackled on the issue of composting and associated health hazards and remarked at one point: “Don't put your head in it!”
His comment followed a statement from Professor Howard Dalton, chief scientific adviser at the Department for Environment, Food and Rural Affairs.
The professor said the study shows “that there are bioaerosols around composting plants during the process. The lesson is that these processes have to be enclosed or there has to be a cordone sanitaire.”
Professor Dalton described how composting involves the “churning up of organic waste and it depends how close you are to it for the levels of disease.” It was this comment that prompted Mr Morley's warning about “putting your head” in compost.
Bioaerosols
Other advisers at the launch noted that the Environment Agency requires a 250m zone around windrow composting because “at that distance the enhanced levels of bioaerosols have fallen down.”
It was concluded overall that based on the research, 250m is a “is a perfectly reasonable distance” but in the future the sector may well be moving to enclosing of composting facilities.
Questioned over what further research needed to be done, the professor highlighted work on landfill releases to soil and water and how people are affected by bioaerosols from compost. And, work needed to be done on MBT (mechanical biological treatment).
MBT
Sources close to the report told letsrecycle.com that it had been hard to assess the health impacts of MBT because there was very little research in this area, which did create something of a gap in the report's findings. However, MBT research is likely to figure in a new round of health and waste work which is to be arranged by DEFRA's waste implementation programme and could get underway this summer.
DEFRA is now hoping that local authorities will be able to use the study when they are proposing new waste management schemes and that it will also be used when the public voice concerns about the plant. But, the report's authors warn that “communicating about health and environmental risks is a challenging problem”.
Copies of report
The review of Environmental and Health Effects of Waste Management – Municipal Waste and similar wastes is available on the Defra website at www.defra.gov.uk/environment/waste/index.htm Hard copies of the extended summary can be obtained from defra@iforcegroup.com
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