Video report by Chris Conway.
Businesses facing charges when a clean air zone comes into force have described the new rules as unfair.
The introduction of a Clean Air Zone (CAZ) in Newcastle city centre is aimed at cutting air pollution caused by older vehicles.
The zone launches in Newcastle on Monday 30 January, and comes after the government ordered the city council to take action to reduce illegal levels of traffic-related pollution as quickly as possible.
With typically more than 400,000 vehicles entering the zone each month, the aim is to improve air quality by reducing the number of high-polluting vehicles on the roads.
It means some older vehicles will be charged to enter the zone, which is causing a financial headache for some businesses.
Keiths Coaches are one business that has been negatively impacted by the Clean Air Zone.
The company has transport contracts with schools in Newcastle and is facing an extra charge of £50 per day per coach that enters the Clean Air Zone because a number of the company's vehicles do not meet the required emissions standards.
Keith Grimes, who owns Keiths Coaches, says he feels it is unfair that local companies face charges when private cars - which may be just as polluting - can drive into the Clean Air Zone without facing a charge.
He said: "At the end of the day that cost has to be passed onto the client and is the client going to be prepared to pay that additional cost?
"It's disappointing to think that the local industries are being targeted. I can understand the clean air zone but I think the boundaries that they've set are too high. At the end of the day the amount of people who go over the Tyne Bridge, it's not all coaches, it's not all vans, it's not all taxis.
"It is literally bread and butter people in their cars going to work."
How will Newcastle's Clean Air Zone will work?
Grants are available to help businesses move to cleaner, greener vehicles and Newcastle City Council says they had little say over who faces charges.
Cllr Nick Kemp, leader of Newcastle City Council, said: "The criteria is set by central government and the minimum requirement for Clean Air Zones is coaches, HGVs and taxis.
"Unfortunately they meet that criteria, which is not set by us."
The toll zone is in Newcastle city centre only, including the routes in over the Tyne, Swing, High Level and Redheugh bridges – and will be active 24/7.
Some of those routes are the most heavily polluted in Newcastle - one of the main reasons why an air quality expert from Northumbria University says the Clean Air Zone is vital.
Professor Anil Namdeo took air pollution readings next to Newcastle's central motorway, with data showing almost 400 micrograms of pollution per cubic meter of air.
The World Health Organisation says that number should be closer to 15.
Professor Namdeo said: "Air pollution is an invisible killer because you cannot see the tiny particles and tiny gas particles which go into our system and absorb into our bloodstream and it affects more the vulnerable population. For example children, the elderly, and people who already have an existing condition.
" Air pollution is the biggest environmental threat to the humanity."
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