Author: TimSC (page 1 of 11)

Air Quality Continues to Worsen Despite First Year of CAZ

Pollution levels in Portsmouth continued to rise during the first of the clean air zone operation. This is the second year in a row that NO2 levels have increased, although the recent increase was small. A similar pattern is seen in both long term (10 years) monitoring sites and a broader set of locations with 3 years of monitoring data. These figures are taken from the city council’s own data.

Portsmouth had a class B CAZ introduced in 29th Nov 2021. The latest air quality report covers 2022 which is the first full calendar year that the CAZ has been in operation. We should expect to see most of the impact of the CAZ fairly quickly after its introduction, based on the experience of other cities.

As can be seen in the above graph, the average NO2 level in the city has risen for the last two years. The government is keen to emphasize the 5 year trend remains downward. The sites currently over the 40 ug/m3 legal annual limit in 2022 are:

  • Alfred Road, 48.54 μg/m3 (AR-Col 9) by the Catholic Cathedral.
  • Alfred Road, 45.89 μg/m3 (AR-Col12) by the Catholic Cathedral. This has almost doubled in the 2020 to 2022 period!
  • Hope Street, 44.88 μg/m3 (HR-opp-Column4, site 120), road by The Cascades car park.
  • Market Way, 48.47 μg/m3 (MW-OppStABS, site 145), behind the former Commercial Road Sainsburys. The pollution level here has more than doubled from 2020 to 2022!
  • Kingston Road, 40 μg/m3 (KR-Col4), by the New Road junction. (An exceedance depending on your interpretation of the legislation. DEFRA are apparently using 40.5 μg/m3 as the limit.) This has almost doubled in the 2020 to 2022 period!

So not only has the CAZ focused on only some of the problem areas by ignoring London Road/Kingston Road, the tread for the last 2 years is actually for an overall worsening air quality! The worsening has been particularly bad along the Alfred Road/Hope Street/Market Way route into the city. The annual report suggests the slower renewal of vehicles during the COVID pandemic might be part of the problem.

Other locations of concern:

  • 152 36.41 ug/m3 Column 171 Southampton Road (SR-Col171), near QA hospital junction.
  • 273 37.7 ug/m3 Old London Road by Protyre
  • 162 36.98 ug/m3 51 Eastern Road (ER-51) by Farlington A27 roundabout
  • 163 36.67 ug/m3 52 Eastern Road (ER-52) by Farlington A27 roundabout
  • 192 37.3 ug/m3 58 Kingston Road, Shirin Kebab

Since 2010, the council has had a legal obligation to bring down pollution levels as quickly as possible. This is on top of the public health need to make the air we breathe safer. However, the actions the council can take are down to central government funding and rules. According to the latest figures, the current plan including the clean air zone has failed. Despite this, there has been no public acknowledgement of this failure or an updated plan that actually addresses the air quality problem. Informally, I have been told that discussions are happening within the council on air quality, probably in collaboration with DEFRA. But I am concerned that this lack of transparency, combined with the track record of failure will lead to yet another unrealistic and illegal plan.

The 2022 NO2 pollution levels look like this:

Minor variations in NO2 levels are caused by changes in weather patterns. I suspect that the slight deterioration in 2022 is within this range, so it is plausible it is due to the weather. However, I would also expect a CAZ to make a significant difference, much greater than the effect of the weather. Instead of a downward short term drop, we are seeing an increase in pollution!

Key quotes from the draft report:

In the long-term, NO2 Annual Mean trend for the last five years (2018-2022) exhibited downward trend at 119 out of 155 locations (76.77%), in the meantime, NO2 Annual Mean trend exhibited upward trend at 36 out of 155 locations (23.23%) for the same period.

Why are we using a 5 year trend? According to the law, air quality targets must be met “as soon as possible” which in this context means within 2 years (that is about how long a CAZ takes to implement which was though of as a “quick” intervention). A 5 year trend also allows the government to rest on their (rather meager) laurels.

Delivery of a Charging Clean Air Zone was forecast to take 12–18 months. As this was Central Government’s preferred tool for bringing down emissions to within legal limits in the shortest possible time, any alternative suggestion would need to achieve the same reduction in emissions in a similar time frame. Therefore, any options which would take more than 24 months were assumed to have failed in the objective to reduce emissions to within legal limits in the shortest possible time.

This is the criteria the government is using for assessing the success of clean air zone, so we can see they have failed even by their own standards.

After extensive studies and numerical modelling, looking at both charging and non-charging options, it was identified that a Class B+ CAZ was needed to bring levels of pollutants down to within legal limits in the shortest possible time … The modelling forecast that this option would be effective at reducing emissions to within legal limits in the shortest possible time. There was therefore no legal need to introduce a CAZ C or D which could charge vans and cars.

The language of this section is misleading because we know now that a class B+ CAZ was insufficient. Therefore, the government probably had a legal obligation to introduce a stricter CAZ, but they failed to do so.

An important implication of the pandemic is the disruption that it was caused to the automobile market. In 2020, new car sales were down to their lowest level since 1992, and the number of newly licensed Heavy Goods Vehicles nationally was at its lowest level since 2014. With the difficulties in obtaining a new vehicle, this has been a boost to the second-hand market. From an air quality perspective, this is problematic as the newer vehicles are significantly less polluting than older vehicles. As a result, the improvement in per vehicle emissions has been less than the improvement that would have occurred without COVID-19 (as without the pandemic a greater number of older vehicles would have been replaced by new cars).

COVID is probably a factor in air quality and the composition of vehicle fleets. However, it doesn’t explain how things have deteriorated in certain hot spots.

Air pollution is the largest environmental risk to public health in the UK and it is known to have disproportionate effects on vulnerable groups. Air quality disproportionately affects the very old, the very young, and those with chronic conditions. It also has greater impact on those who live, work, or go to school in more deprived areas.

We must keep in mind the reasons for fixing air quality and the urgency of the task.

NO2 Annual Mean increased between 2021 and 2022 at 113 out of 227 locations (48.78%) and decreased at the remaining 114 (55.22%).

The report doesn’t state that the increase in pollution in the former is greater than the decrease in the latter. I guess the annual status report doesn’t want to produce a single figure for the entire city because it is arguably an over-generalization but at the same time it makes the report hard to understand.

PS I have created an FOI request for the 2023 data.

Clean Air Zones Being removed despite climate emergency

A number of recently introduced clean air zones are being dismantled because air pollution in their area has reduced to within the legal limit. This includes CAZs in Fareham, Greater Manchester and Bradford but the plan is to eventually remove all CAZs outside London. The CAZs were introduced solely to tackle air pollution. However, this ignores the elephant in the room of climate breakdown. CAZ areas could easily be repurposed to help with a “modal shift” away from private car usage. According to mainstream climate scientists:

the world needs to achieve net zero carbon dioxide (CO₂) emissions by 2050 to limit warming, and that all scenarios consistent with the 1.5 C target include an immediate and rapid decline in fossil fuel use.

Of course, people need reliable alternative transport options. This needs investment as a matter of urgency. People are struggling in the cost of living crisis. However, this is made worse, not better, by living in a car culture that effectively subsidizes their use. This includes subsidies to fossil fuel companies, health care for people affected by air pollution, road building and maintenance, parking provisions, crash damage, productivity lost waiting in traffic jams, and the impact of climate change. To say cars are cheaper is simply untrue.

We need to make our cities car free zones. (Electric cars are not much better because they incur most of the same costs on society.) We can’t wait around and we need to use all available tools to achieve this quickly. The fact this is not even being discussed is sign the government is not taking the climate crisis seriously.

PS. One of the reasons the government keeps missing air quality targets is likely to be the increase in new car size of 5mm a year.

Update: Slightly old news… Cllr Gerada asked PCC about air quality improvement measures at a full council meeting in Oct 2023 and was answered by Gerald Vernon-Jackson. (Time stamp 4:49:30) Gerald said the money spend on the CAZ would be better been spent on free bus travel and a targeted car scrappage scheme. Gerald also said he suspected the CAZ has not achieved the drop in pollution required and this is because DEFRA based it on (national, low resolution) modelling data rather than the actual local air quality data provided by the council. (Strongly agree with him on this! I wrote previously “In some cases the model disagrees with where problematic areas are within the city e.g. focusing on the bottom of M275 (Mile End Road) while ignoring Fratton Road/Kingston Road/London Road. Since it misses known pollution black spots, we have a significant reason to doubt the validity of the model.”)

Update: 2023 Air Quality Status Report (draft?) (which contains data for 2022). Summary of the report.

Portsmouth CAZ Fails To Bring Pollution DOWN TO Legal Limit

On the 2nd anniversary of the Portsmouth Clean Air Zone introduction, I received the following email saying the CAZ failed to achieve its stated goal of bringing air pollution within legal limits.

We are emailing to let you know about an important update on Portsmouth’s Government mandated Clean Air Zone (CAZ).

The latest government assessment reveals that the air quality standards have not yet been met, which means Portsmouth will need to keep it’s Clean Air Zone for longer than hoped to further improve air quality in the city. While an encouraging 94% of monitored areas comply with air quality standards, specific locations continue to face persistent challenges.

Please be assured that we are actively collaborating with the Joint Air Quality Unit within the government to consider the options for a way forward in improving air quality. Currently, this involves continuing to charge non-compliant Taxis and PHVs, buses, coaches and HGVs to travel within the Clean Air Zone.

For more information, please view our latest news item at cleanerairportsmouth.co.uk

If you have any questions or queries, please drop us a reply to this email.

Regards

Nathan Goodyear

Engagement Officer Transport Delivery

This broadly agrees with the initial analysis I performed in July. Both central and local governments have failed to get a grip on the problem by consistent over-optimism and doing the bare minimum. They need to recognize that exceeding air pollution reduction targets are a benefit that will result in heath improvements and cost savings.

The city council has blamed central government for not funding alternative transport schemes. Cabinet member for transport Gerald Vernon Jackson said “We have always said to Government that the mandated Clean Air Zone is not enough to reduce air pollution. The recent funding for better bus travel, improved walking and cycling routes and zero emissions buses are a start but far more is needed to ensure Portsmouth prospers and we protect the health of people in our city. … For the mandated Clean Air Zone to work the government needs to significantly invest in transforming the way people can travel in Portsmouth in the same way they have done in London so that it is easier to choose a cleaner journey and for businesses to operate in a more sustainable way.”

The air quality law came into effect in 2010 and states they should bring down pollution “as soon as possible”, so the government have had 13 years to sort this out. To misquote a certain movie: “Every day that air pollution remains high is one more failure. 4735 days, gentlemen… 4735 FAILURES!

PS 2nd Dec is World Pollution Prevention Day

Clean Air Zone Removal Will Wait Until Air Quality Achieved

From a Portsmouth City Council officer:

The Clean Air Zone (CAZ) is in place until compliance with legal limits have been met and have been proved to be permanent. Portsmouth will need to have been compliant with legal limits for at least two years and provide demonstratable evidence in the success of the measures to improve air quality, such that the removal of the Clean Air Zone will not lead to a reversal of these.

The CAZ will have been operating for two years by the end of November 2023; therefore, the earliest we would be able to demonstrate the above would be by the end of Year 3 – November 2024. However, this is dependent on air quality data showing a consistent and sustained reduction in pollution levels, and subject to Government approval.

The first year operational report is available here: Reporting – Cleaner Air Portsmouth . The report does not include air quality outcomes as this data is being analysed by central Government; we are expecting the first year air quality report this Autumn. Once these findings have been provided, a review of the air quality impact of the CAZ will be brought to Cabinet.

If you want to ask further questions about the Clean Air Zone or air quality, please do feel free to come to us direct via the CleanerAir email address – I’ve copied it in.

Clean Air Zone had Little Impact According to Provisional 2022 Data

Portsmouth City Council kindly provided new air quality data up until November 2022 as part of my FOI request. We can see long term trends over the last several years. The overall air quality has not significantly changed since 2020. This is disappointing since the Clean Air Zone was introduced at the end of November 2021 and should have improved air quality fairly quickly. However, the scheme was watered down to exclude some of the most polluted areas in Portsmouth, such as Kingston Road and London Road. The impact of the CAZ seems to have been very small overall.

Note that my analysis is provisional since I only had 11 months of data and I had to estimate the NO2 bias correction. (I used 0.836, being the average from 2019-2022). Also, the effect of the CAZ can be masked by annual fluctuations in weather which also impacts air quality. The official analysis by the city council is due this summer but they have been late with reports in the last few years.

Locations over legal limit from provisional 2022 data:

  • hs-oppcol4 47.5 ug/m3 Uncertain location, Hope Street or High Street?
  • 117 47.0 ug/m3 Alfred Road Column 9 near the Catholic Cathedral
  • 118 44.8 ug/m3 Alfred Road Column 12 near the Catholic Cathedral
  • 120 45.5 ug/m3 On Market Way Opposite MW-StABS (MW-OppStABS)
  • as-osabs 42.7 ug/m3 Unknown location, only 2 months’ data

There are still a number of areas that are above the legal annual NO2 limit and sites along Alfred Road and Market Way are actually getting worse! The council has an obligation to reduce air pollution as quickly as possible and, while progress has been made, they have repeatedly failed to meet the legal requirement since the rules came into force in 2010. The failure of the Clean Air Zone to bring the city within legal limits demonstrates the government is not taking the issue seriously.

Thankfully, many of the highly polluted areas are not in residential areas. I am concerned this might lead the government to claim that these areas are not legally protected. This is despite Victoria Park, the Catholic Cathedral, the Queen Street Naval Barracks and the Cascades Car Park being adjacent to these polluted locations.

I am unsure as to the location of “as-osabs”, as well as a few other locations, and I will try to find out.

Other locations of concern:

  • 152 35.5 ug/m3 Column 171 Southampton Road (SR-Col171), near QA hospital junction.
  • olr-col2 36.5 ug/m3 Uncertain location: Old London Road?
  • 162 35.2 ug/m3 51 Eastern Road (ER-51) by Farlington A27 roundabout
  • 163 35.2 ug/m3 52 Eastern Road (ER-52) by Farlington A27 roundabout
  • 192 36.6 ug/m3 58 Kingston Road Shirin Kebab
  • 213 35.7 ug/m3 Kingston Road Column 4, near Sultan Road junction

These areas remain close to the legal limit. Studies have shown that any level of air pollution is harmful and we need to work to make these areas healthy for residents and workers. It is likely government will focus on illegal air locations while neglecting areas that are within the legal limit but almost as bad.

What we need is an expanded and strengthened CAZ, as well as safe cycling routes, investment in public transport and low traffic neighborhoods. Unfortunately, both local and national governments claim these measures are not affordable. However, large savings will be made by health benefits of improved air quality and active travel.

Update Feb 2024: I’ve posted the final data for 2022 and the situation is slightly worse than presented here.

Comments on 2022 Portsmouth Air quality Report

I’ve found some interesting sections in the 2022 Annual Status Report for Portsmouth air quality. Comments below.

It is recognised that air pollution has negative effects on health and can have a disproportionate impact on the most vulnerable in society such as children, older people, and those with pre-existing medical conditions. … Attributing health outcomes from exposure to individual constituent pollutants in emissions is not simple. This supports the need to tackle emissions in general and not necessarily to focus on individual pollutants. However, with reference to the limit and target values, the main pollutant of concern in Portsmouth is Nitrogen Dioxide (NO2). … since 2018 parts of Portsmouth not previously assessed under the LAQM regime and where there is an absence of long-term public exposure (pavements alongside busy roads with no nearby relevant exposure as identified in the 2018 Local Air Quality Management Technical Guidance (LAQM.TG(18)) became a new focus.

Good introduction. However, newer research seems to indicate that particulates are causing more harm than NO2. The legal limits are stricter for NO2 so political focus is on the wrong thing.

x4 Engagement Officers employed to engage directly with stakeholder groups – a great model which has now been broadened to wider transport scheme delivery. … There are a number of key challenges to successful implementation of planned schemes, as well as future work planning including:
* Securing long-term funding which directly supports delivery air quality interventions.
* Staff capacity to deliver schemes and monitor the air quality impact
… The impact of the increasing demands for data upon the existing staffing resource of 1 FTE created significant problems in respect to mandatory reporting during 2021/2022. This resourcing issue has been carefully considered and additional funding has now been provided to Regulatory Services (RS) to secure additional personnel to maintain the existing R&A requirements and the further reporting needs which have arisen as a result of the CAZ. It is therefore anticipated that PCC will be better placed to meet the requirements of DEFRA, both in relation to the ASR reporting process, and reporting the performance of the CAZ, moving forward.

Lack of staff would explain why the council has been very slow in answering my FOI request. It also mentions funding required to fix air quality problems is mostly controlled by central government.

Two local road sections in central Portsmouth were identified where modelled NO 2 concentrations are forecast to exceed the statutory limit of 40 μg/m3 (or 40.49 μg/m3 unrounded) in 2022. These are:
•A3 Alfred Road (Unicorn Rd to Queen St, 41.7 μg/m3)
•A3 Commercial Road (south of Church St, 41.1 μg/m3).
These road links are located in the city centre area, on the main A3 route in and out of the city. An estimated reduction in NOx of 4%-7% is required to achieve the statutory limit. … The data that central government use to monitor compliance with legal limits is currently based on their national Automatic Urban and Rural Network of air quality monitors and modelled concentrations from the Pollution Climate Mapping (PCM). This is different from the data that PCC collect to monitor air quality in the city. In future, it is likely that a combination of monitored and modelled data will be used to assess compliance.

Portsmouth has a network of NO2 measurement points to find if a location is within legal pollution limits. However, there may be NO2 hot spots that are not currently being measured. It may be beneficial to try to predict where polluted areas might be using a computer model. However this depends on good pollution and traffic data being available to use as inputs to the model. It is generally preferable to rely on real measurements where possible, sometimes be adding additional measurement points to suspected hot spots. If the model disagrees with direct measurement data, we should usually trust the direct measurements. In some cases the model disagrees with where problematic areas are within the city e.g. focusing on the bottom of M275 (Mile End Road) while ignoring Fratton Road/Kingston Road/London Road. Since it misses known pollution black spots, we have a significant reason to doubt the validity of the model. This has lead to the CAZ to be smaller than it should be. Using both data sets in future seems to be a sensible improvement.

Portsmouth is under ministerial direction to reach the legal limit in the shortest possible time. In the absence of any intervention, compliance would be achieved in 2023 at the identified exceedance locations, due to assumed background changes in fleet composition. However, the coronavirus pandemic has created some uncertainty around the background rate at which vehicles are renewed, due to a decline in the number of new vehicle registrations in the first six months of 2020. This could extend the baseline year of compliance. … An important implication of the pandemic is the disruption that it was caused to the automobile market. In 2020, new car sales were down to their lowest level since 1992, and the number of newly licensed Heavy Goods Vehicles nationally was at its lowest level since 2014. With the difficulties in obtaining a new vehicle, this has been a boost to the second-hand market. From an air quality perspective, this is problematic as the newer vehicles are significantly less polluting than older vehicles. As a result, the improvement in per vehicle emissions has been less than the improvement that would have occurred without COVID-19 (as without the pandemic a greater number of older vehicles would have been replaced by new cars).

Portsmouth has relied heavily on the replacement of older vehicles being replaced with newer less polluting ones. However, the renewal rate is somewhat unpredictable as people’s preferences change and the economy varies. As I understand it, the council missed targets to be in compliance a few years ago since SUVs became more popular which lead to greater emissions than predicted. Now we are told vehicle replacement has slowed down due to COVID. This is clearly not a reliable approach to reaching compliance, or at least the vehicle renewal predictions should be treated as unreliable.

Because of the danger to human health that poor air quality poses, Portsmouth is legally obliged to bring levels of NO2 down to within legal limits in the shortest possible time. This meant that PCC had to take stringent actions, such as introducing the CAZ and its complimentary measures. This may bring Portsmouth into compliance with legal limits, but it is recognised that there is still further to go to improve air quality and residents’ health and wellbeing. … After extensive studies and numerical modelling, looking at both charging and non-charging options, it was identified that a Class B+ CAZ was needed to bring levels of pollutants down to within legal limits in the shortest possible time. … The modelling forecast that this option would be effective at reducing emissions to within legal limits in the shortest possible time. There was therefore no legal need to introduce a CAZ C or D which could charge vans and cars.

The claim that a class B CAZ would bring pollution down as fast as a class C or class D CAZ is absurd and flies in the face of common sense. Obviously if more vehicles are included in the scheme, it will have a greater effect. What the council really means is if we look at different scenarios and only consider the effect on an annual basis, class B would be sufficient. This seems to ignore the “as soon as possible” requirement in law and is therefore illegal. Their CAZ plans also depend on the unreliable vehicle renewal predictions.

Portsmouth will need to have been compliant with legal limits for at least two years and provide demonstrable evidence in the success of the measures to improve air quality, such that the removal of the Clean Air Zone will not lead to a reversal of these.

The CAZ will not be ‘switched off’ as soon as legal limits have been met – this runs the significant risk that air quality would just return to levels seen before the CAZ was introduced. Instead, the CAZ will be decommissioned when real world data and modelling demonstrates that removing the CAZ is unlikely to result in emission levels reaching above the legal limits.

It seems reckless and shortsighted to be considering removal of the CAZ at all, when considering the climate emergency. Just because the air quality situation slightly improves, doesn’t mean our air is safe to breathe or that there are no other pressing reasons to retain the CAZ.

As UK emissions reduce, transboundary particulate matter – which is not directly reducible through national action – and natural emissions become a larger fraction of the PM that remains. In the long-term however, PM2.5 must inevitably reach a non-zero plateau in concentration that cannot be practically reduced further through reasonable technical or policy interventions. That value will depend on willingness to abate the remaining controllable emissions and external factors relating to natural emissions, geography, and weather. The complex contributions to future PM2.5 make this the most difficult pollutant to forecast long term with confidence.

I thought this seemed rather defeatist but then remembered that particulates are caused by salt from sea spray, dust from fields and pollen from plants. Some sources of particulates cannot be practically removed.

New Portsmouth Air Quality Data published

Two annual reports detailing air quality in Portsmouth landed on my desk for 2021 and 2022. Thanks D, that will keep me busy! Why the council could not provide this under my pending FOI is still a mystery.

First let us examine the long term trend:

There was a slight increase in 2021 when compared to 2020 but not by much. As predicted, the decrease caused by Covid-19 has been reversed as people return to their normal behaviour.

DEFRA recognise that air pollutant concentrations will have been impacted by the change in activity observed across the United Kingdom (UK) as a result of COVID-19 and the Government’s associated measures to combat community transmission of this virus since March 2020. … When considering the 2021 data provided within this ASR the council recommends exercising caution in interpreting the efficacy of improvement measures on pollution concentrations as it is likely that restrictions on activities will have had a notable impact on measured concentrations following the Government’s lockdown measures, restrictions and advice. … It should again be noted that, as a result of the impact of the Covid-19 pandemic, levels of pollution fell uncharacteristically in 2020 and therefore it may not be unexpected that increases in NO2 occurred in 2021 as traffic levels returned to pre-pandemic levels when compared with the levels recorded in 2020. Therefore, a collation between levels of NO2 increasing in 2021 as a consequence of other contributory factors is uncertain.

Annual Status report (ASR) 2022

We don’t have data for when the CAZ was in effect, but hopefully that is published soon.

Improvements were seen at 23 St Nicholas Street (19 ug/m3), UTC Portsmouth (19 ug/m3) and 2a/2b Gladys Avenue (22 ug/m3). London Road (The Tap pub) is now just within the legal limit (36 ug/m3).

Deteriorations were seen a opposite Sainsbury Hope Street- Col4 (45 ug/m3) and at Alfred Road Column (42 ug/m3) and are now above the legal limit. The biggest deterioration was seen at Column 96 Southampton Road (36 ug/m3) but this did not breach the limit. Some of these swings were so wild I suspect some sort of error but we will see in future years.

Despite the work that has and continues to be undertaken, the city still faces challenges to reduce the concentrations of harmful pollutants in the air.

ASR 2022

Sites out of compliance in 2021:

  • 145 Opposite former Sainsbury Hope Street (45 ug/m3)
  • 117 Alfred Road Column 9 near the Catholic Cathedral (43 ug/m3)
  • 229 Eastern Road-Column 59 on the bridge to Farlington Roundabout/A27 (42 ug/m3) (new monitoring site!)
  • 118 Alfred Road Column 12 near the Catholic Cathedral (42 ug/m3)
  • 232 Fratton Road-Column 23 by Farmfoods (41 ug/m3) (new monitoring site!)

A downward trend emerged at all 162 monitored locations in the last 5 years since 2017 similarly to the monitored locations for the 5-year period commencing in 2016. For the same monitored locations, NO2 annual mean levels were in excess of the annual mean NAQO in 2021 at the same two locations where the annual mean was breached in year 2020. … A closer examination of the newly added 72 NDDT monitored locations in 2021 revealed that two locations are likely to be in breach of NAQO. These are located at the top of the Eastern Road and in Fratton Road which are not located in AQMA or within the geographical location of the CAZ. NDDT data capture from these locations was less than 25% (therefore unreliable) and was not subjected to any form of corrections.

ASR 2022

The council have greatly expanded the NO2 monitoring network which has identified a number of new areas of concern. It illustrates pollution hot spots might still exist if adequate monitoring is not performed. We can only be sure we are in compliance if all measured points are well within the limit.

PCC has frequently revised its non-automatic monitoring of NO2 network via Nitrogen Dioxide Diffusion Tubes (NDDT) expanding it to reach 233 sites in 2021 (not including co-location sites) as a result of the additional monitoring requirements of the CAZ.

ASR 2022

Some are barely within the legal limit (40 ug/m3) and should be grounds for further action.

  • 233 Fratton Road-Column 31 by St Mary’s churchyard (39 ug/m3)
  • 267 London Road-Opposite Column 23 at Bustop, near Leaders in North End (39 ug/m3)
  • 273 Old London Road- Column 2, near Protyre/John Wesley Gardens (39 ug/m3)
  • 227 Eastern Road-Column 118 near the junction for Morrisons (38 ug/m3)
  • 268 Mile End Rd -Market Tavern Column 66A (38 ug/m3)
  • 216 Alfred Road CAQMS-R6 near the Catholic Cathedral (37 ug/m3)
  • 282 Velder Avenue-Column 5, near Milton Cemetery (37 ug/m3)
  • 262 Kingston Road-Column 11 near Tofu Cute/Esso garage (37 ug/m3)
  • and several others

I’ll post again when I have a chance for a more through read of the reports.

Let Pompey Breathe on BBC Politics South

I was interviewed about the clean air zone and air pollution in Portsmouth. The full segment is available on BBC iplayer. #PoliticsSouth

Also a written version of the piece is on their site.

UPDATE: I was also interviewed by Heart Hampshire and Capital South Coast radio. It should be broadcast 31st May afternoon or 1st June morning.

UPDATE: “The benefits from reducing the harm to health are often calculated to add up to many times the cost of action

Q and A on Portsmouth air quality

Do you hear that idling is an issue when you’re doorknocking? Is there a good road for me to go to and do some doorknocking myself?

I’ve not been doing much door knocking, but I only heard the issue mentioned once locally in person, on local social media or local media. Warblington School is next to a level crossing and motorists run their engines despite the signs. (They are in Havant not Portsmouth.) Engine idling is a kind of issue you would tackle if your council department had very little money and you didn’t want to offend the motorist lobby. It’s good but it hardly acknowledges the scale of the air pollution problem.

Is the general view the Clean air zone is making any difference or it’s not?? Do you get complaints about it? I know you said you would like it extended – can you explain where you think this is needed? Or just expanding the vehicles involved?

It’s hard to determine the effect of the CAZ because the council has not released the relevant data. I’ve been waiting months for an FOI for the data to be released. This is probably because the air quality group in the council have been understaffed and have a backlog of reports they legally need to produce. I have written about this previously in more detail.

Even with the data being available, it will be tricky to interpret because of the effect of COVID-19 lock downs that reduced traffic around the city. We can also analyze the data in terms of long term trends but this may require future data to make the situation clear.

I have not heard much negative feedback probably because the CAZ doesn’t affect most people directly. Private cars are not covered under the current scheme.

The main contributor to bad air quality in the city are diesel vehicles. As we discovered during dieselgate, manufacturers have been cheating their emission tests which where actually much worse than they said. Many cities have introduced clean air zones and we can learn from their experiences. The London ULEZ has been expanded with added restrictions over its history, including charging older diesel private cars. A number of German cities introduced environmental zones but they had to restrict private diesel vehicles in order to meet their targets. Portsmouth should consider similar measures for the sake of public health, and before it is forced to by central government. The CAZ area should also be expanded because several of the worst air pollution areas are outside the clean air zone! e.g. London Road in North End.

If we consider the climate emergency and not just public health, we should be considering banning all internal combustion vehicles from the city (with limited exceptions). Climate scientists are in general agreement that only a very rapid reduction in fossil fuel use will avert catastrophic climate change. This would also greatly benefit air quality and public health.

 Can you think of the “carrots” – rather than the sticks (fines/charges) – which I should be talking about, which are working or aren’t? School Streets? Voi scooters?

Portsmouth City Council has done some work in improving cycle routes but a great deal more needs to be done. After the debacle of the Elm Grove cycle way, they seem to be proceeding cautiously. Schemes like the “low traffic neighbourhood” in Maxwell Road, Landguard Road, Tredegar Road and Reginald Road by changing them to one way roads are fairly pathetic. Other schemes like the Active Pompey Neighbourhoods seem to be more ambitious with roads possibly being closed to make active travel safer. I hope this is not watered down when it comes to implementation. The delayed cycle hire scheme has finally arrived and could be a useful transport alternative. There is still a lack of cycle storage with many houses in Portsmouth being terraced making domestic cycle storage difficult. I personally don’t even have a garden to store bicycles in a shed. More bicycle locker installations are being trialed by the council but progress is slow as usual.

These schemes need to be strengthened and rolled out across the city. This is of course difficult with council funding being squeezed by central government. Additional investment is needed in bus transport, possibly with a publicly owned integrated transport similar to Transport for London. Again, we need to learn from places that have largely achieved modal change in city transport such as the Netherlands. However, we need to complete the transition in a very short time, rather than decades.

Impact of Portsmouth CAZ: Data Pending

Portsmouth City Council (PCC) recently held a Climate Change and Environment briefing which reported on the current status of pollution in the city. Initial figures for the Clean Air Zone (CAZ) were reported but the message remains “we await more data before drawing conclusions”. A webcast is available if you want a more audio oriented overview. I’ll try to summaries new items arising here.

The 2021 Annual Status Report (ASR) was apparently submitted to DEFRA ~19 months late but it doesn’t seem to be publicly available. The 2022 is ~7 months late and a draft is expected at the end of Feb 2023. Apparently the council department were lacking necessary workers to complete the reports but they said this has been rectified. The council has a legal responsibility to publish these air quality reports in a timely manner.

PCC has again expanded it’s NO2 monitoring network to get additional data on the CAZ. 72 new nitrogen diffusion tubes in 2021 bring the total to 233 sites. An additional continuous monitoring station has been installed in Alfred Road near the Catholic Cathedral.

Air quality reports from 2020 and 2021 has been released in summary form. As I reported before, 2020 showed a decrease in pollution around the city, largely due to COVID-19. Only 2 locations were above the annual NO2 limit (Alfred Road and Hope Street) in that year. Pollution levels remained more or less constant in 2021 in my rough analysis while PCC reported a slight downward trend. The same two locations were above the legal limit but two newly established monitoring points have readings that are of concern.

The CAZ was introduced at the end of Nov 2021. Since the impact of a CAZ is usually a short term one-off improvement, based on the experience of other cities, all eyes are on the 2022 data which has yet to be released (expected June 2023 but I put in an FOI). The location of the CAZ was largely determined by computer models as DEFRA found that two locations were predicted to be above legal limits. I don’t have much faith in their modelling as we know from direct measurement that other areas like London Road in North End are above the legal limit but excluded from the clean air zone. This seems to me a mistake. And after the 1 year anniversary, the impact of the CAZ is largely being assessed by DEFRA based on modelling data, so the effect of COVID can be removed. I consider this questionable since they are already focusing on the wrong roads to begin with. Remember, actual measurements almost always trump modeled data.

8.4 Our understanding is that for year 1 of the CAZ the national compliance assessment is based on measurement data from the national Automatic Urban and Rural Network and modelled concentrations from the Pollution Climate Mapping model and not from other data sets including our monitoring data.

8.5 The Government are currently investigating a number of options for improving the national compliance assessment to better reflect local situations, including options for incorporating local monitoring data collected as part of their central evaluation. As we move further into year two of the CAZ the focus upon and need for accurate validated monitoring data will significantly increase which PCC will provide to DEFRA.

8.6 As the 2022 data set is not due to be published in June 2023 further updates in respect to such cannot be provided at this time. Additionally, as a result of monitoring data taking primacy in respect to assessing the performance of the CAZ during of 2023 it is too early to assess its performance and whether the predicted ‘do nothing’ compliance dates as specified in Section 3.3 have been achieved.

PCC have the 2022 data but it seems to me they are too busy analyzing the 2020-2021 data to properly provide an assessment on the CAZ. The council’s regulatory services guy did indicate we might have to wait until late 2023 or early 2024 before we get a clear picture. As I mentioned, I put in an FOI to get the raw data and I will try to do a basic analysis myself. I’m less concerned with the exact impact of the CAZ and more with the overall pollution levels and trends around the city. I don’t want to wait until the Summer to understand were we stand on air quality.

In other news, a new study links air pollution with mental illness even at low levels of exposure. By the time you get to 30 ug/m3, the effect on mental health has already “done it’s worst”! And the UK is still aiming for 40 ug/m3?

Study results suggest that estimates of long-term exposure to multiple air pollutants was associated with increased risk of depression and anxiety. The nonlinear associations may have important implications for policy making in air pollution control. Reductions in joint exposure to multiple air pollutants may alleviate the disease burden of depression and anxiety. […] the nonlinear exposure-response curves suggested that the risk of incident depression and anxiety tended to be steeper at lower air pollution levels and plateauing at higher exposures, which have important implications for policy making in air pollution control. […] Considering that many countries’ air quality standards are still well above the latest World Health Organization global air quality guidelines 2021, stricter standards or regulations for air pollution control should be implemented in the future policy making