The issue of air pollution came under the spotlight at the planning inquiry into the controversial revamp of Anglia Square.
Norwich Cycling Campaign says the £271m development is in an area where pollution already being above targets and will increase pollution further.
But developers Weston Homes/Columbia Threadneedle say air pollution will reduce in the years ahead.
Air quality consultant Melanie Hobson, giving evidence on behalf of the applicants, said overall air pollutants in the area are already falling, according to the city council's monitoring.
She said that diffusion tube monitoring showed nitrogen dioxide concentrations are estimated to be above the annual objectives at six locations, including at St Augustine's Street, Magdalen Street and New Botolph Street, in 2031.
But she said not all those locations would have residential development, so targets do not apply to them. She said, where there are homes, mechanical ventilators or filters, are to be fitted.
And she said air quality would get better in the future, as vehicle emission standards get more stringent and more people switch to electric cars.
She said the development would not lead to an "unacceptable risk" from air pollution.
The Norwich Cycling Campaign questioned the developer's modelling, saying it was 'flawed' - a claim denied by the applicant.
And they claimed the 'canyonisation' of Edward Street would increase pollution.
The scheme includes more than 1,200 new homes, including in a 20-storey tower, a hotel, cinema, car parks and new shops.
The Anglia Square plans were agreed by Norwich City Council in 2018.
But the planning inquiry was triggered after Historic England and other opponents asked for a government call-in.
The heritage organisation had objected due to the massing and height of the revamp - and its impact on the historic city skyscape, including Norwich Cathedral.
After planning inspector Dave Prentis has heard the inquiry's evidence, he will come up with a recommendation for the secretary of state, who will ultimately decide if the Anglia Square revamp should go ahead or not.
MORE: GP fears Anglia Square revamp would exclude people from Mile Cross
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here