Nitrogen dioxide levels have improved since the pre-pandemic situation. That said monitoring suggests an increase in regional pollution levels since 2020 or 2021. The two previous calendar yeas were influenced by changes in travel behaviours. During 2022 services have rebounded with an increase in some vehicle types in and around travel corridors running through our six Air Quality Management Areas (AQMAs).
This year Bureau Veritas have produced a complementary report that present results from the Sussex monitoring network for Nitrogen Dioxide (NO2), fine Particulate Matter (PM2.5 and PM10), Sulphur Dioxide (SO2) and Ozone (O3).
The city council continues with its automatic analyser located next to the bus ultra-low emissions zone set back from North Street. DEFRA automatic analysers for oxides of nitrogen, particles, and ozone are in Preston Park. The University of Brighton continues to monitor pollutants at Falmer.
For 2022 calendar year the city council has submitted to DEFRA verified results for eighty-two Nitrogen Dioxide (NO2) diffusion tubes. Additions include pre-scheme (baseline); road and kerbside monitoring prior to possible cycle lanes and pilot liveable Neighbourhood area in Hanover and Tarner.
Subject to the required procurement approvals funded is allocated to install additional automatic monitoring stations for daily and hourly pollutant monitoring. This will also help enable the verification of real-time sensors across the city.
Since the last annual report, the city council has undergone a detailed consultation on its Air Quality Action Plan (AQAP). Members at committee approved the plan for the period 2022 to 2027, with more stringent air quality targets. Options remain to review or amend the city’s smoke control areas. Most recently members have decided to enforce vehicle anti-idling a measure aimed at reducing emissions and fumes.
Between December 2022 and May 2023 Brighton & Hove buses have completed another round (52) bus exhaust upgrades for cleaner buses. The benefits of these additional buses achieving ultra-low emission standards is set to be recorded by our local monitors from 2023 onwards. This report present monitoring prior to this most recent intervention.
Below is a commentary on each Air Quality Management section with a consideration of vehicle count changes in recent years up to the end of 2022. More detailed charts on long term changes to pollution are presented in the main body of the report.
Citywide and background air quality
Particulate levels across the city are close to achieving 2040 national targets proposed at 10 µg/m3 as an annual average for PM2.5 (airborne particles less than 2.5 microns). A reduction in concentrations will have benefits for health at a individual and population level. Monitoring suggests particulate levels are higher in built-up areas compared to the South Downs National Park. Based on the monitoring to date particulate levels are not higher next to local roads which suggests a variety of near and far emission sources contribute to local air quality. Road traffic including motorways contribute to secondary atmospheric pollution including particulates composed of nitrates. Sulphurous fuels and emissions have diminished substantially compared to historical levels. The monitoring we have so far indicates that particulate concentrations have not improved in recent years. Caution is required when comparing different particulate monitoring methods. A funded project is working to upgrade the particulate monitoring network across Sussex. The purpose of improved monitoring is raised awareness and community engagement.
Nitrogen Dioxide (NO2) concentrations at background sites such as across suburbs have gradually improved since 2010 and 2017, that said there is a slight regional increase in outdoor NO2 since 2020_2021. In Brighton & Hove this has been monitored in Portslade (Vale Park), Preston Park (North Brighton), Pavilion Gardens (City Centre) and most recently on Rottingdean Sea Front. All background monitors are remote from roads, outside of the designated AQMAs and represent the regional air quality situation.
A270 Old Shoreham Road (OSR Outside of AQMA)
Since 2021 a diffusion tubes survey has monitored kerbside and roadside NO2 next to the Old Shoreham Road (A270) in Portslade (western part of the local authority). Its purpose was to provide an effective baseline ahead of a potential cycle lane that aims to promote sustainable travel and reduce carbon. Where vehicle accelerate eastbound from the Lock Hill junction diffusion tubes at the kerbside railings record high levels of NO2. The concentrations dissipate within one to eight metres. It is recommended that monitoring continues near to the boundary of Brackenbury primary school. Outside the AQMA at relevant receptors NO2 is compliant with air quality standards.
A259 Kingsway (Outside of AQMA)
Since 2021 a diffusion tubes survey has monitored kerbside and roadside NO2 next to Kingsway (A259). It provides monitoring ahead of a possible extended cycle lane that aims to promote sustainable travel, reduce fuel consumption and carbon. Annualised levels of NO2 monitored 2021 and the full calendar year 2022 indicate that NO2 is close to half the national air quality standards and easily meets the more ambitious AQAP target of 30 µg/m3. Further intervention and improvement would help work towards World Health Organisation (WHO) guidelines for air quality.
Hanover and Tarner Pilot Liveable Neighbourhood LN (majority outside the AQMA)
To determine a pre-scheme, baseline for outdoor air quality a diffusion tube monitoring survey has been carried out for potential Hanover and Tarner LN area and its boundary roads.
2022 (annualised) results indicate outdoor Nitrogen Dioxide (NO2) in this area is most concentrated at the base of the slope, at the frontages of properties adjacent to the A23 (Grand Parade 41 and 38 µg/m3) and A270 (Lewes Road 46 and 42 µg/m3) that is part of AQMA1. At the rear of roadside buildings, recorded NO2 concentrations drop-off substantially by half. For this reason, new ground floor flats at roadside (since 2007) are designed to have their ventilation air intakes at the back.
Between 2001 and 2008 diffusion tubes monitored NO2 outside Elm Grove Primary School. Over this eight-year period the average was 33 µg/m3 NO2 (maximum 38 µg/m3 in 2004 minimum 30 µg/m3 in 2008). At the same location in 2022, resumption of NO2 monitoring outside the school indicated close to 26 µg/m3. This outdoor concentration complies with the ambitious target of 30 µg/m3 set out in the City Council’s 2022 AQAP.
NO2 at upslope and mid-slope locations in Hanover set back from main roads indicate levels are 18 to 20 µg/m3, the same as Pavilion Gardens (urban background). This level of NO2 in outdoor air is less than half (46%) of national air quality standards.
The following sections refer to vehicular traffic trends and NO2 monitors along travel corridors in the Air Quality Management Areas last amended and designated in 2020. Trend graph for NO2 pollution concentrations in around the AQMAS are given in the main body of the report.
AQMA1 A2010 Around Brighton Railway Station
The main railway station is an important transport interchange. Automatic traffic counters on Queens Road (south of Brighton train station) record a reduction in car and van counts since 2018/19. Bus counts have been relatively constant. As train activity increases service vehicles flows around the station have recovered compared with 2020, but not to pre-pandemic levels. This observation suggests behavioural change (since Q1 of 2020) with less commuting compared to the years prior to the pandemic. Taxi pick-up has moved to the east side of the train station which would partly explain the reduction in car trips on Queens Road. Vehicular numbers in combination with the proportion of ultra-low and zero vehicles influences road traffic emissions and roadside air quality.
AQMA1 North Laine through traffic
Frederick Street-Gloucester Road east of Brighton railway station is an important access route that services residences and the pedestrianised Brighton Laines. Interestingly traffic counters since 2018 record a significant decrease in the number of cars using the link. There has been an increase in goods vehicles both vans and lorries suggesting a switch to deliveries. In this case source apportionment changes as the local air quality stays the same since 2020.
AQMA1B2066 Bus Ultra-low Emission zone
Weekday bus counts on North Street are ordinarily constant. A reduction has been recorded from nearly 2800 a day in 2019, 2367 for 2020, back up to almost 2500 a day in 2022. With the introduction of zero capable hybrid buses (2018 and 2019) and a higher proportion of ultra-low vehicles the bus fleet is becoming cleaner. Further improvements such as exhaust upgrades have been delivered during 2023. Lorry counts on North Street have declined. Car counts on North Street had a daily average in 2019 of almost 3100, 2300 in 2020 recovered to 2900 in 2022. NO2 along the ULEZ travel corridor has improved substantially over the past five and ten years. The smaller increase in NO2 monitored in 2022 (compared to previous years) is also recorded regionally.
AQMA1 A23 Valley Gardens
From September 2019 the western side of Valley Gardens has been allocated to buses and taxis and the eastern side to general traffic two-ways; northbound and southbound. This helped to accelerate the rate of improvement in NO2 on the east side and the amount if traffic using the A23 into Brighton. Around Valley Gardens, NO2 reduced substantially between 2010 and 2020, the smaller increase since 2020 is also recorded in other areas. Further improvements are required to easily comply with national air quality standards and push towards WHO guidelines. 40 µg/m3 NO2 (UK standard exceedance) is recorded on one of three Grand Parade façade diffusion tubes in 2022.
AQMA1 A23 / A270 Preston Circus
Monitoring of vehicles along Beaconsfield Road (A23) shows a long-term decline in the count of cars from 14,000 per day in 2013 to 11,000 in 2022. There is a gradual reduction in the number of daily lorries using this section of the A23 from 620 in 2014 to 438 in 2022. Conversely the number of average daily buses has increased from 138 in 2011 to 243 in 2019, since falling back to 183 in 2022. Noticeably the number of vans (light goods) has increased as follows:
Weekday average van (Light Goods) counts in the AQMA near Preston Circus
Most vans will be older diesels that contribute to oxide of nitrogen emissions. That said light goods vehicle deliveries can save car and lorry trips. Following a dip during the pandemic car counts on New England Road were higher in 2022 compared with 2018, NO2 has reduced considerably since 2010 with a smaller uptick since 2021.
AQMA1 A270 Lewes Road
This is the link between the City Centre the University of Brighton and the University of Sussex. Buses constantly shuttle both ways day and night. Late 2022 the fifteen-year-old bendy buses were taken out of service and replaced with ultra-low vehicles. This reduction in emissions will influence roadside pollution and the benefits of this change will be monitored 2023.
In terms of planning the Lewes Road travel corridor is typically maisonettes, with retail ground floor and roadside residential use from ground floor upwards. There are many take-away food outlets. Vehicle counters record an increase in motorbikes and vans most likely involved in servicing and deliveries. Recent monitoring indicates exceedance of national NO2 standards within 125 meters of Elm Grove and Vogue Gyratory junctions. NO2 levels have gradually improved long term and further improvement is required. On Hollingdean Road demolition of roadside terraces and replacement with new developments will change how air circulates in the street and further pollution monitoring is scheduled since NO2 exceedance was monitored 2002 to 2019.
There is long term decrease in cars using the A270 with a smaller increase since 2020. Explanations of charts and graphs are provided in alt text.
Long term weekday annual average car counts in the AQMA along the A270
AQMA2 B2123 / A259 Rottingdean
Counters in Rottingdean High Street since 2020 show car and van counts have declined. At the same time the weekday count of lorries (heavy goods) has increased.
Long term counts of cars on the A259 show a gradual decrease as follows:
Long term weekday annual average car counts in the AQMAs along the A259
Roadside NO2 levels in Rottingdean (chart in the main report) have decreased substantially since 2010, 2017 and 2018. An increase in NO2 is monitored for 2022 compared to 2020 and 2021. Further improvement is required to close the difference between roadside and background levels and achieve better than the 30 µg/m3 target set out in the City Council’s 2022 Air Quality Action Plan (AQAP).
AQMA3 A259 / A293 South Portslade
The above graph is also relevant to AQMA3 in the west of the local authority area. Lorries (heavy goods haulage from the Shoreham port inland) along the A259 in Portslade have declined from 934 weekday average in 2019 to 800 for average weekdays in 2022. Vans (light goods) have also decreased in this area suggesting reduced activity for industries in the port area. It appears to be the opposite trend to vans and motorbikes associated with take-aways and home deliveries. Along Wellington Road buses have increased from 337 average weekday in 2018 to 463 in 2021 and 416 in 2022. After long term improvement there is an increase in monitored NO2 in 2022 compared to 2021 (a trend graph is included in the body of the report).
AQMA4 Sackville Road
The development site adjacent to Sackville Road was not fully used prior to major construction. A traffic survey is required to determine long term trends in the various vehicle types. NO2 has improved since 2010, 2013 and 2016. The NO2 annual mean for 2022 indicates an increase compared with 2020 and 2021. Monitoring indicates pollution is lower than the pre-pandemic situation.
AQMA5 A23 Preston Road South Road and the Drove
A traffic survey is required to determine long term trends in various vehicle types using The Drove west of the railway in AQMA5. NO2 has been slow to improve near the hairpin hill climb linking with Millers Road a trend chart is included in this report.
AQMA6 Eastern Road, Royal Sussex County Hospital
The hospital includes trauma, cancer care and neo-natal units. Improvement in air quality in the area will benefit health at a population level including people spending time in the infirmary. Monitoring suggests heavy construction traffic required for the hospital re-build contributed to higher roadside NO2 2016 to 2018. Long-term improvement has been monitored in NO2 at the façade adjacent to Eastern Road, near the main hospital buildings. The national standard and AQAP target are met. Further improvement is required for this AQMA and surroundings to work towards WHO health guidelines. Hybrid buses operate in zero emission mode outside the hospital.
Officers have recommended that Combined Heat and Power gas combustion with emission at height at the hospital is refused by planning and gas combustion is phased out.