EMISSIONS from Plymouth's giant incinerator are the highest ever recorded in a UK residential area, new data has revealed.
Plume Plotter - a site which plots incinerator pollution - has released graphics which show high concentrations of nitrogen oxide near the incinerator in Barne Barton, St Budeaux and Devonport.
But the site, developed by a Gloucestershire resident who wanted to get an objective idea about the everyday effects of a local incinerator on air quality, also showed pollution being spread as far away as Cornwall and Dartmoor.
Fig. 1 Smoke emerges from the incinerator
The founder of Plume Plotter, who has asked not to be named, said these new figures were the highest he had seen in a residential area - but did add this is because of the incinerator's close proximity to densely populated neighbourhoods.
"I've been testing the Plymouth incinerator for about four weeks now, in which time I've seen concentrations of nitrogen oxides up to 10 micrograms per cubic metre at ground level near the site," the founder explained.
"Compared with other incinerators that I've looked at, this is not quite the highest but it is the highest I've seen in residential areas. This is mainly because of the incinerator's position.
"In general, the worst pollution is quite close to the incinerator but, in the case of Plymouth, the city is quite densely populated and the emissions seem to affect a lot of people - even in Roborough, Bickleigh and Southway.
"I can't say whether the levels of pollution predicted are harmful because I'm not a health expert but the levels of pollution are pretty high compared with the existing background levels."
Plume Plotter calculates how high the plume rises and how it disperses with distance and then displays how much pollution may reach certain areas.
It is based on AERMOD, a world-renowned air pollution modelling system, and uses current weather conditions, upper air data as well as information on incinerator emission rates to predict where pollution will fall.
Fig. 2 The incinerator in St Budeaux
The founder added: "Plume Plotter was developed to help local people know where pollution will fall at any time, so they can take action to avoid it."
Nitrogen oxides, if consumed, has been proven to cause breathing difficulties, damage to lung tissue and, in extreme cases, premature death.
Small particles can penetrate parts of the lungs and can cause or worsen respiratory disease such as emphysema and bronchitis, and aggravate existing heart disease.
Paul Carey, who is the managing director of incinerator site operators MVV Environment, said traffic and other "industrial emissions" will have contributed to the figures.
Fig. 3 Paul Carey
"NOx levels are heavily influenced by traffic and other industrial emissions," he said.
"We carried out dispersion modelling back in 2011 using the Environment Agency's approved model and this demonstrated that ground level concentrations of all emissions due to our facility were well within allowed limits."