They will burn industrial and household waste. The plume from the chimney will emit many hazardous chemicals. These will include dioxins, PCBs, heavy metals, sulphur dioxide and nitrogen dioxide. They will contaminate both the air and the soil over a wide area.

See links below for more information

 http://news.bbc.co.uk/1/hi/england/leicestershire/8589372.stm
 http://www.foe.co.uk/resource/briefings/incineration_health_issues.pdf
 http://www.environment-agency.gov.uk/research/library/consultations/117003.aspx
 http://www.loughboroughecho.net/news/loughborough-news/2010/03/31/your-views-wanted-on-proposals-for-incinerator-at-newhurst-quarry-73871-26146076/
www.saigcampaign.co.uk