Fears over London's future pollution threat
Environmental campaigners have said they fear the level of pollution in east London could get worse with plans for new river crossings.
Plans for vehicle crossings at Silvertown and Gallions Reach have been put forward.
Tests in the proposed-crossing areas in east London, conducted on behalf of Friends of the Earth, found some pollution levels exceeded EU limits.
Transport for London (TfL) said the schemes would bring economic benefits.
The tests for nitrogen dioxide (NO2) were carried out by residents using diffusion tubes on behalf of Friends of the Earth in June.
The results showed that half of the 32 locations tested exceeded the EU level of 40 micrograms per cubic metre of air.
Newham Way on the A13 was the worst location - registering a level of 61.
Jenny Bates from Friends of the Earth said: "Allowing any new road river crossing or City Airport development as proposed would be a traffic-generating, congestion-worsening, air quality-deteriorating disaster.
"Instead a package of non-road alternatives such as DLR (Docklands Light Railway) extensions, ferries and cheaper bridges for walkers and cyclists must be considered."
Currently, the only crossings for cars and lorries between Rotherhithe and Dartford are the Blackwall Tunnel and Woolwich Ferry.
'Saving time and money'
In a statement, TfL said: "With London's population set to grow to 10 million by the early 2030s new river crossings in east London are crucial to manage demand.
"Providing the Silvertown Tunnel as an additional river crossing would reduce the time vehicles currently spend queuing in traffic - helping to reduce vehicle emissions while saving people and businesses time and money."
Plans put forward for new a Thames crossing include building a new road tunnel linking Silvertown to the Greenwich Peninsula, a ferry at Gallions Reach linking Thamesmead and Beckton or a proposed fixed bridge at Gallions Reach.
Consultations on the schemes will begin later this year.
TfL added that since Boris Johnson began his term as London Mayor emissions of NO2 were down by an estimated 20% due to measures brought in, including tighter emission standards for lorries.