Results from Wandsworth Council’s air quality monitoring stations at seven sites across the borough show a drop in NO2 and PM10.
In Putney mean levels of NO2 measured on the High Street kerbside monitoring station were 66 micrograms per cubic metre. In 2017 the figure was 76.
However, they still breached EU NO2 limits during 25 hours, which they say was during rush hour.
Previous research carried out by the council showed that buses were a large contributor to pollution in Putney. The council lobbied TfL for cleaner buses and last year Putney became the capitalâ€™s first low-emission bus zone.
The council also introduced a daytime delivery ban for lorries and is currently working with TfL to improve traffic flow down Putney High Street.
Elsewhere in the borough, levels of PM10 were down compared with 2017. The number of days that levels exceeded EU limits halved in Nine Elms (from 16 to 8) and Lavender Hill (4 to 2) and fell from 11 to three in Tooting High Street.
The figures will now be sent for checking by independent auditors and will form part of the councilâ€™s annual report on air quality submitted to the Greater London Authority later this year.
The councilâ€™s transport and air quality spokesman Jonathan Cook said: ‘Iâ€™m delighted that for a third year running air pollution levels appear to have dropped dramatically, especially in Putney.
‘Our close and increasingly joined-up focus on this issue, together with effective working with partners such as TfL, has certainly paid off. We will also continue to make it easier for people to choose greener travel, such as electric cars and would encourage people to use more active methods of travel such as walking and cycling whenever they can.
‘We will continue to work hard to reduce pollution levels still further, and are keen to work with the local community to help achieve this. Please get in touch if you can help with our anti-idling work outside schools.’