The following three charts present the concentrations of NO2, PM10 and PM2.5 as reported contiuously at reference sites in this borough and nearby, doing so as annual averages for the average of each consecutive month.  The source of this data is Air Quality England (ratified until 31 06 2023 or later).

"North Kensington" is classified as an "urban background", where there is little traffic and industry.  The NO2 chart illustrates the improvement since introducing the ULEZ.  The improvement attributabe to expanding both the LEZ and the ULEZ is masked by the impact of covid-related lockdowns.  Construction works adjacent the Shepherds Bush monitoring device explain the 2022 peak in PM10 concentrations at that site.

Data reported for other continuous monitoring devices by the Council is at best indicative.  Prior to 2023, the data reported by some was clearly spurious.

Click the following names for information concerning NO2 concentrations in those wards:

Notting Dale

Pembridge

Stanley 

Norland
[air quality in the vicinity of Holland Park Avenue has long been ignored, despite prosals for a cycleway; although a low cost monitoring unit was installed during May 2022, it has yet (early September 2022) to generate useful data; deploying this brand of monitoring unit would appear cynical given (1) the huge discrepancies between ratified and provisional data typical of the other monitors used by RBKC and (2) the improbable concentrations recorded, especially for PM2.5.  The data for NO2 at the Kensington High Street sites of two of these devices bears little resemblance to data (see the following chart ) for the large number of diffusion tubes concurrently deployed (which implicitly offer better value for money.

Nitrogen dioxide concentrations along Kensington High Street (based on Air Quality Annual Status Report for 2021 and a Freedom of Information request; raw data not adjusted for bias)

Multiplying the 2021 data shown above by 0.83 (the bias adjustment factor adopted by RBKC council) the right hand of the chart suggests that, in 2021, air quality along Kensington High Street was illegal for much of its length, 12 years after the deadline for compliance.  As a proxy for progress towards net zero, this ominously reflects disregard for public interest. (NO2 in urban areas derives primarily from combustion of diesel and, for central heating & hot water, methane.)

Concentration of NO2 at eastern end of Kensington High Street
(based on RBKC Air Quality Annual Status Report 2021 and adjusting diffusion tube for bias)

The chart above tends to confirm that the devices deployed at sites KCM01 and KCM02 generate spurious data for NO2, whether or not the data is adjusted for presentation in RBKCs Air Quality Annual Status Report.  The data for PM2.5 is unusable.  It is unclear why this data is published (including by airqualityengland.co.uk)

The following chart shows how the annual average concentration of NO2 changed between 2010 and 2021 at prominent sites in the Royal Borough of Kensington and Chelsea (- the data derive from monthly measurements by diffusion tubes):

Source:  based on “Air Quality Annual Status Reports”  Royal Borough of Kensington and Chelsea)

The data above indicate that NO2 concentrations continue to exceed the legal limit at almost all the sites shown. The legal limit (40 micrograms per cubic metre) should have been achieved by 2010.  The legal limit is four times greater than the World Health Orgnisation guideline.  The improvement since 2019 is attributable to the ULEZ (and the LEZ and their extensions). 

Court rulings subsequent to cases brought by ClientEarth oblige government to ensure NO2 concentrations decline to beneath the legal limit in the shortest possible time.

Research by Imperial College [see / listen from minute  15:10] indicates that NO2 concentrations are unlikely to meet that requirement, particularly along those busy streets (and in their neighbourhood), even when the proposed Ultra Low Emission Zone is fully implemented across London.