AQE 2024, the Air Quality and Emissions show will take place on 9 and 10 October at the NEC in Birmingham, with the most exhibitors and most expansive conference program of any AQE or MCERTS event since 2002, as the organizers explain.

The health effects of air pollution, combined with the climate effects of greenhouse gases, are increasing public, media and political attention on the measurement of air quality and emissions. At the same time, technological advances are helping to find new insights into pollution mitigation, and AQE will provide attendees with the latest information on the regulations, standards, methods and technologies that can help in the fight against air pollution and climate change.

AQE 2024 has been designed to meet the needs of anyone involved with air quality and emissions reduction. This includes, for example, regulators, local authorities, consultants, instrumentation engineers, laboratory staff, process operators, engine and powertrain developers, researchers and interested stakeholders such as clean air campaigners.

With over 200 of the industry’s leading technology and service providers gathered in one place, there will no better opportunity to learn about the latest developments, discuss environmental monitoring challenges, and compare products through face-to-face interaction with air quality and emissions experts. Beyond the exhibition floor, the conference schedule is fully packed with over 100 hours of free technical workshops and presentations, delivered by regulators, researchers, and industry experts. Visitors will be provided with access to a wide range of highly topical presentations, covering issues such as ambient air quality monitoring – regulations and the latest technological innovations, including low-cost sensors, mobile sensors and the utilisation of cellular communications networks to create very large monitoring networks. There will also be parallel sessions on emissions monitoring, addressing measurement quality and the latest developments in standards, methods and techniques. In addition, attendees will be able to choose from further parallel sessions covering the monitoring of methane, hydrogen and carbon capture and storage.

The AQE website www.ilmexhibitions.com/aqeshow provides comprehensive details on the event, as well as a link to register free of charge. Visitors to AQE 2024 will also have access to WWEM 2024, the water, wastewater and environmental monitoring event, which will be co-located at the NEC.

Planting trees may worsen, not improve, New York City air, says a new study, since interactions with man-made pollutants can create ozone.

New York City is planting tens of thousands of trees each year. They provide shade, lower surface temperatures by releasing moisture, absorb a surprising amount of airborne carbon, scrub out soot and other floating pollutants, and provide wildlife habitat along with just plain beauty. What could go wrong?

Something could go wrong, according to a new study. Oaks and sweetgums, which currently account for a majority of the city’s trees, produce huge amounts of volatile compounds called isoprenes. Harmless by themselves, isoprenes interact rapidly with polluting nitrogen oxides emitted by vehicles, buildings and industry to form ground-level ozone―a prime factor in many respiratory ailments, especially chronic bronchitis and asthma.

The research, carried out at the Columbia Climate School’s Lamont-Doherty Earth Observatory and other institutions, appeared to find that if the city maintains past species patterns in new plantings, isoprene production in Manhattan in coming decades will go up by about 140%, and resulting summer ozone levels by as much as 30%. In Queens, which has the most room of any borough to support more trees, isoprene production could quadruple, with corresponding increases in peak ozone; the other boroughs are somewhere in between. The study was published in Environmental Science & Technology.

“We’re all for planting more trees. They bring so many good things,” said study coauthor Róisín Commane, an atmospheric chemist at Lamont-Doherty. “But if we’re not careful, we could make air quality worse.”

“There is no reason to think that trees don’t play a role in what’s in the air,” said lead author Dandan Wei, who did the research as a postdoctoral scientist at Lamont-Doherty. “We just didn’t have the tools before this to understand this particular aspect.”

The leaves of some tree species emit isoprene as a byproduct of photosynthesis, though no one is quite sure why. With oaks, emissions tend to increase exponentially with heat, at least until air temperatures reach the high 90s. Some scientists think this helps keep leaf tissues from drooping and losing their ability to photosynthesize as it gets hotter. Emissions of these and other volatile compounds by trees may also have something to do with attracting pollinating insects. For whatever reason, oaks and sweetgums are especially prolific; oaks emit some 800 times more isoprene than low emitters like maples or London planes. (Fun fact: the oak-rich Blue Ridge Mountains get their bluish tinge when seen from afar due to vast amounts of isoprene and other volatile compounds reacting indirectly with water to form tiny floating droplets.)

New York City is home to some seven million trees, covering 22% of the surface, according to the city Parks Department. Parks and forests contain some five million, of which more than half are oaks of various kinds and sweetgums (37% and 17% respectively). On the streets, (close to 700,000 trees at last count), oaks comprise 18% and sweetgums just a small number. London planes are the most common street trees, comprising a third. Some 130 other species account for the rest.

The authors of the study analyzed newly available satellite imagery showing the city’s tree canopy in 30-by-30-meter grids, and combining it with 2016 and 2018 Parks Department censuses of tree species. This was combined with data from scientists including study coauthor Andrew Reinmann, an environmental ecologist who does lab experiments on tree leaves to measure their isoprene production under different conditions. The researchers scaled up the lab data to the city’s actual tree coverage, and modeled how trees interact with tailpipe and building emissions of NOx.

They found that emissions from trees play a controlling role in the formation of ozone on hot summer days, when levels routinely exceed the federal safety levels of 70 ppb. Levels sometimes now reach 100 ppb; the addition of new trees could eventually drive it up even further, says the study.

New York has made some headway at reducing nitrogen oxides in recent years, but the pace has been agonizingly slow. The study says that at current rates of 2% to 5% a year, it would take 30 to 80 years for the city to reduce emissions by a factor of five―the level at which emissions from trees would no long play a role in ozone formation.

No quick fix appears to be imminent. In June, New York Gov. Kathy Hochul canceled a plan decades in the making to reduce vehicle traffic by imposing congestion pricing in Manhattan. Meanwhile, the City Council passed a 2023 resolution calling for an increase in tree-canopy coverage from its current 22% to at least 30% by 2035. This would require 250,000 new trees.

A 2018 study carried out by Parks Department researchers concluded that city trees emit more than 800 tons of volatile compounds each year, including isoprene. But both the researchers of this study and the Parks Department have preferred to position blame with vehicle engines rather than trees.

The department has already reduced the proportion of oaks it plants in favor of a more diverse mix―but more because of a need to diversify species rather than because of the isoprene question.

“We’re not going to go cutting down any big old oaks,” and neither will the department completely stop planting new ones, said Auyeung. “You have to think about what you would lose if you do that.” Oaks are keystone species, she pointed out, providing food and habitat for native insects, birds and mammals.

Ultrafine particles, UFPs, the smallest particles that contribute to air pollution (and still a challenge to measure), hinder the function of mitochondria in human olfactory mucosa cells, according to a new study, findings that appear to clarify some of the adverse health effects believed to be linked to exposure.

Led by the University of Eastern Finland, the study appeared to show that traffic-related UFPs impair mitochondrial functions in primary human olfactory mucosa cells by hampering oxidative phosphorylation and redox balance. The responses of olfactory mucosa cells of individuals with Alzheimer’s disease differed from those of cognitively healthy controls. The findings were published in Redox Biology.

Air pollution is believed to constitute a major global burden on people’s health, and it has been indicated as a risk factor for dementia, including Alzheimer’s disease, AD. Despite the growing body of evidence, the role of UFPs in the cellular and molecular changes in the human brain leading to Alzheimer’s disease remains obscure.

The olfactory mucosa is a sensory tissue responsible for odour detection, and it is directly exposed to the environment and in contact with the brain. Interestingly, one of the earliest clinical symptoms of Alzheimer’s disease is an impaired sense of smell. The Kanninen Lab at the University of Eastern Finland uses a physiologically relevant human-based in-vitro model of the olfactory mucosa, which is generated from cells obtained from voluntary donors and collected in collaboration with Kuopio University Hospital. Earlier studies by the Kanninen Lab have shown that this model recapitulates AD-related alterations, which makes it suitable for investigating air pollution and its connection to AD.

“Dysfunction of mitochondria plays a key role in the development and progression of neurodegenerative diseases such as AD, and mitochondria are known to be especially vulnerable to environmental toxicants. Still, the connection between UFPs and mitochondrial functions in the context of AD has not been previously investigated in the human olfactory mucosa,” says first author, Doctoral Researcher Laura Mussalo of the Kanninen Lab at the University of Eastern Finland.

The study explored molecular mechanisms of how UFPs affect the mitochondrial function of olfactory mucosa cells from cognitively healthy individuals and individuals diagnosed with Alzheimer’s disease. The researchers compared responses in mitochondria of these two health status groups by examining gene expression, and with functional assessment. The researchers were also interested in determining whether fossil and renewable diesel fuels cause different effects, and how modern aftertreatment devices in the engine, such as particulate filters, affect the responses observed at the mitochondrial level.

The study provides evidence of traffic-related UFPs being able to reach even the inner mitochondrial membrane, impair oxidative phosphorylation, and cause mitochondrial dysfunction. Both gene expression level alterations and functional studies confirmed disruptions in mitochondrial respiration, decreased ATP levels, and alterations in redox balance leading to increased oxidative stress. These alterations were strongest in response to exhausts derived from an engine without aftertreatment devices. However, the exhaust from an engine with after-treatment devices showed only negligible changes. Responses observed in cells from individulas with AD were slightly deviating from those of the controls, suggesting AD-related alterations in olfactory mucosa cells upon exposure to UFPs.

There is an urgent need to understand the interplay of air pollutants and human health in order to steer the political decision-making for efficient reduction of air pollutants, which could, in the long run, reduce the economic burden caused by adverse health effects. This study provides important information on the increased sensitivity of individuals with AD to the effects of air pollution exposure. It also provides new insight to form the basis for mitigation and preventive actions against the health impairments caused by UFP exposure.

The study constitutes part of TUBE project, which was funded by the Horizon 2020 programme of the European Union. The study has also received funding from the Kuopio Area Respiratory Foundation, the Finnish Brain Foundation, Yrjö Jahnsson Foundation, Päivikki and Sakari Sohlberg Foundation, and The Finnish Cultural Foundation’s North Savo Regional Fund.

The Seminar programme at this year’s Air Quality & Emissions show (AQE 2024) will feature a presentation on the use of AI in air quality by Airly co-founder and CEO Wiktor Warchałowski.

AQE 2024 will take place at the NEC in the UK, on 9^th and 10^th October, and Wiktor’s seminar, which is free to attend, will begin at 10:30am on the second day.

“This seminar will be essential viewing for air quality professionals looking to better understand the role of automation and AI in their daily work. Wiktor will explain how a new AI tool can be exploited to dramatically improve the speed and efficiency of the initial, more mundane elements of air quality report generation. In doing so, Wiktor will demonstrate the ways in which AI and automation can be used to enable air quality experts to make better use of their skills and expertise.”

The seminar will feature a real-life case study, as well as best practice for implementing AI technology, drawn from industry research, interviews with over 300 air quality consultants, and feedback from organisations that are already utilising AI and automation in air quality.

AQE visitors will be able to participate in a practical demonstration of the Airly AI tool at the company’s exhibition booth – M15. The company’s air quality sensors will also feature on the booth, as well as screens providing access to air quality data from networks of Airly sensors in the UK and overseas.

Registration at www.ilmexhibitions.com/aqeshow/ is free of charge, and provides access to the AQE Seminars, Conferences and an International Exhibition. Registered attendees are also able to access the co-located WWEM 2024 event, which focuses on testing and monitoring in the water and wastewater sectors.

Using gas hobs and ovens without adequate ventilation causes high levels of NO2 and PM around the home, according to a new study.

A paper published in Heliyon reported the findings, from researchers led by a team from the University of Birmingham.

The group set up air sensors in seven indoor and three outdoor locations in an Oxford-based house during March-June 2020 to observe different levels of NO2 and Particulate Matter (PM) over a period of 100 days. Data were combined with domestic activity logs to assess the impact of different chores – such as cooking and cleaning, undertaken by the householders and pollutant levels were compared the World Health Organization health-based guidelines.

Levels of NO2 were observed to be more than five times (562%) higher in the kitchen during the study compared to background levels, and four times (412%) higher than concentrations observed at the front of the house. The kitchen also saw guideline-breaking levels of NO2 each day during the study, and unventilated cooking with gas stoves and ovens were associated with peak air pollutants.

As with many households during the start of the pandemic, a spare bedroom was used as a study by the participants. Sensors in this bedroom observed the highest peaks of fine particles PM1 and PM2.5 in the house and activity logs show that the peaks also correspond with cooking activity as well as use of a printer. This suggest that pollutant emissions are travelling around the house, concentrating and accumulating in spaces with poor ventilation.

Dr Suzanne Bartington, Clinical Associate Professor in Environmental Health at the University of Birmingham and co-author of the study said:

“We were surprised by the high levels of particle pollution in the bedroom (used as a study) and the very high concentrations of NO2 from gas cooking in the kitchen which are higher than typical roadside concentrations albeit for relatively short durations. The key thing that we noted was that the high levels are associated with activities in the home and as a result there are both policy and individual actions that can be taken to limit indoor exposure.

“It seems what you do in the house may just as, if not more important, than where the house is for many around the country seeking to minimise their exposure to air pollutants.”

Dr Felix Leach, Associate Professor of Engineering Science at the University of Oxford and co-author of the study said:

“Too often when we think about air pollution, we think about road traffic and coal-fired power stations. However, we generate plenty of pollution in our own homes too. Thanks to the indoor environment, which is often very poorly ventilated – perhaps due to insulation efforts, this pollution can build up to far higher levels indoors than are ever seen outdoors.

“This study looks at how typical household activities can generate pollution that then moves round the house. I myself am much more mindful of my and my family’s indoor air pollution exposure as a result of having done this work.”

The research team acknowledge that the study was conducted during the first COVID-19 lockdown in March-June 2020. As a result, outdoor pollution levels were lower than the five-year average. In addition, there were higher levels of indoor activity with all residents working from home during the study.

A laser-based technology developed at TU Graz can provide continual real-time analysis of air pollutants and their interaction with other gases and sunlight – with revolutionary import, suggest the group.

Sunlight has a major influence on chemical processes. Its high-energy UV radiation in particular is strongly absorbed by all materials and triggers photochemical reactions of compounds present in the air. A well-known example is the formation of ground-level ozone when UV light hits nitrogen oxides. A research team led by Birgitta Schultze-Bernhardt from the Institute of Experimental Physics at Graz University of Technology (TU Graz) is now utilising this high reaction potential for a new method of environmental monitoring. They have developed the world’s first broadband UV dual-comb spectrometer with which air pollutants can be continually measured and their reaction with the environment can be observed in real time. A paper on the development has been recently published in the journal Optica.

Dual-comb spectrometers have been around for almost 20 years. A source emits light in a broad wavelength range, which, when arranged according to its optical frequencies, is reminiscent of the teeth of a comb. If this light penetrates a gaseous material sample, the molecules it contains absorb some of the light. The altered light wavelengths allow conclusions to be drawn about the ingredients and optical properties of the analysed gas.

Making molecules vibrate
The special feature of the spectrometer is that a laser system emits double light pulses in the ultraviolet spectrum. When this UV light meets gas molecules, it excites the molecules electronically and also causes them to rotate and vibrate – exhibiting so-called rovibronic transitions – in a manner unique to each gaseous substance. In addition, the broadband UV dual-comb spectrometer combines three properties that conventional spectrometers have so far only been able to offer in part: (1) a large bandwidth of the emitted UV light, which means that a great deal of information about the optical properties of the gas samples can be collected with a single measurement; (2) a high spectral resolution, which in future will also enable the investigation of complex gas mixtures such as our Earth’s atmosphere; and (3) short measurement times when analysing the gas samples. “This makes our spectrometer suitable for sensitive measurements by which changes in gas concentrations and the course of chemical reactions can be observed very precisely,” said Lukas Fürst, PhD student in the Coherent Sensing working group and author of the publication.

Test case: formaldehyde
The researchers developed and tested their spectrometer using formaldehyde. The air pollutant is produced when fossil fuels and wood are burned, as well as indoors through vapours from adhesives used in furniture. “With our new spectrometer, formaldehyde emissions in the textile or wood processing industries as well as in cities with increased smog levels can be monitored in real time, thus improving the protection of personnel and the environment,” said Schultze-Bernhardt. The application of the spectrometer can also be transferred to other air pollutants such as nitrogen oxides and ozone and other climate-relevant trace gases. The team hopes this will provide new findings about their effects in the atmosphere. Based on this, new strategies for improving air quality could be derived.

Black carbon (BC) – comprising airborne soot-like carbon particles – is gaining prominence on the radar of those concerned with air quality. Envirotec spoke to Acoem about the measurement challenges it presents, and how these are being addressed.

With its significant health and climate impacts, BC is a pollutant that would seem to be ripe for the appearance of legislation or at least clear WHO air quality guidelines to assist with curbing it. But it’s not quite that simple.

In contrast to many other pollutants, for which standardised measurement protocols are available, with numerical air quality guidelines issued by the WHO,¹ BC measurement is not backed by this kind of detail, which would support the introduction of an enforceable limit. As Jost Lavric of Acoem Environment explains, the absence of standardisation may still stand in the way of implementing routine BC measurements on a large scale.

However, efforts to standardise the metrics used for BC measurement appear to be making progress. One prominent initiative is stanBC, a European project carrying the full title, “Standardisation of Black Carbon Aerosol metrics for air quality and climate modelling”, a group in which Acoem is a stakeholder.

BC is produced by the incomplete combustion of fossil fuels and biomass. It is estimated that, on average, household energy and transport are responsible for about 75% of the BC emissions globally, with the source proportions varying between different regions.² BC is formally defined as an ideally light-absorbing substance composed of carbon,³ and optical methods have dominated approaches to measuring it. The designation generally applies to the smaller-sized fractions of particulate matter – between 0.5 µm and a few nanometres in diameter.

PM2.5 mass concentration, a well-established parameter in air quality monitoring regimes, is defined as particulate matter with an aerodynamic diameter of 2.5 µm or less. It will thus include an unknown of quantity of BC, which will also have the tendency to represent a significant part of the ultrafine particles fraction (UFP; smaller than 0.1 µm).

As BC’s distinct, negative impacts and provenance come into sharper focus, there will likely be greater impetus to monitor and regulate it separately. Its health effects are considered more insidious than the larger particle PM fractions, since the smaller the particles, the deeper they can penetrate the body – with the finest particles being able to infiltrate blood vessels and organs. In addition, BC is also recognised as a significant contributor to global warming.⁴

Origins story
BC measurements are often focused on establishing the provenance and age of particles. As Jost Lavric explains, the system under study is a very dynamic one. If you put the same particle in different environments, the materials that absorb to its surface will vary. Typical adherents include condensing rainwater, volatile organic compounds, salts, and other materials (metals deriving from certain combustion processes and so on). With these additions, the light absorption properties of a particle will change, an effect that means optical measurements can probe into its history.

“Every component in the system will influence how the particle absorbs light of different wavelengths,” says Lavric. There are several instrument types that can help uncovering such details, but they can often be large, expensive and difficult to use. Tape-based absorption photometers such as the Met One Instruments powered by Acoem’s BC1054 multi-wavelength black carbon analyser provide a convenient solution for reliable and autonomous real-time measurements of BC concentrations. They are based on measuring light transmittance across a filter media, where the particles accumulate, at ten different wavelengths between the UV and IR part of the spectrum.

With the BC1054, it is possible to characterize the properties of a particle very accurately, probing deep enough into its history to ascertain, for example, whether it was produced by a combustion process in one type of engine as opposed to another, says Lavric.

The instrument can be used in many settings but is aimed primarily at the scientific researcher. It can, says the product literature, be used to provide BC data with levels of accuracy and precision on a par with industry standard reference monitors, but at a fraction of the cost.

For applications, where an increased granularity of BC data or rapid and uncomplicated deployment are prioritised (e.g., for emergency responder situations, or roadside monitoring), Acoem’s BC 1060 & 1065 portable or rack-mounted, and the C-12 low-cost portable monitors are a good choice, says Lavric.

They are intended for users with less exacting requirements for depth of characterisation (compared to the BC1054), and offer a greater focus on portability and affordability. The BC 1060 and 1065 instruments measure the absorption of two wavelengths of light – 370 nm (UV) and 880 nm (IR) – and are suitable for determining the source of a BC particle (i.e., did it come from a wildfire or a car engine?), and providing a basic exploration of its origin. The same measuring technology is used in both, but the BC1060 comes in a weatherproof enclosure, while the 1065 is a rack-mounted system for installation in a laboratory or suitable enclosure.

The C-12 is described as a revolutionary device, packaged in a weatherproof and optionally solar powered compact enclosure. It can be deployed quickly to deliver remotely and autonomously high-quality data from urban or remote locations.

As Acoem’s Derrick Jepson explains, such instruments fit well within a larger picture of BC measurement. He underlines the importance of our developing knowledge on BC (and ultrafine particles in general) being backed by continuous technological and analytical advancements.

Whatever the instrument, the requisite backdrop of standards and calibration metrics is still evolving, making projects like stanBC a very important piece of the puzzle.

Notes
[1] WHO global air quality guidelines: particulate matter (‎PM2.5 and PM10)‎, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide (2012) https://www.who.int/publications/i/item/9789240034228
[2] https://www.ccacoalition.org/short-lived-climate-pollutants/black-carbon
[3] https://stanbc.com/wp-content/uploads/2024/04/Ciupek_STANBC_EAC2023.pdf.
[4] https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM_final.pdf

A new study attempts to disentangle the global interplay of particulate matter (PM2.5) and ozone (O3) pollutants, and makes an urgent call for integrated strategies to curb their detrimental impacts on human health and the environment. Its authors say the research unveils the spatial and temporal dynamics of compound pollution, offering a blueprint for a coordinated global response.

Air pollution is a severe risk to human health and the environment, particularly from fine particulate matter (PM2.5) and ozone (O3). Despite global efforts, many cities continue to face significant exposure risks from these pollutants. PM2.5 and O3 originate from similar sources and interact in complex ways, compounding their harmful effects. Addressing these intertwined pollutants requires innovative strategies. In-depth research is needed to develop effective strategies for joint PM2.5 and O3 control.

In this latest study, the research team – from Hubei University of Economics, Nanjing University, and Yangtze University – looked at  the spatial and temporal patterns of PM2.5-O3 compound pollution. Published in Eco-Environment & Health, in April, the research analyzed data from 120 cities worldwide between 2019 and 2022, proposing a framework for synergistic pollution control.

The study appeared to reveal that nearly 50% of cities worldwide are affected by PM2.5-O3 compound pollution, with hotspots in China, Korea, Japan, and India. Significant spatial correlations between PM2.5 and O3 concentrations are apparent, driven by common precursors such as nitrogen oxides (NOx) and volatile organic compounds (VOCs).

It seems to be a particular problem with cities in Asia, especially India and China. The study attributes this to the high speed of economic development, with its concomitant anthropogenic emissions, “particularly of VOCs and NOx, which are precursors that promote O3 production”.

The study findings highlight the potential for joint pollution control measures, say the authors. The proposed framework aims to manage emissions from both pollutants simultaneously, leveraging their spatial and chemical interactions. Key findings included the identification of cities with high exposure risks and the demonstration of a positive spatial correlation between PM2.5 and O3 concentrations, suggesting that integrated control strategies could significantly enhance urban air quality and public health.

One recommendation is that areas particularly affected by compound pollution – such as India and China – could focus on strengthening control measures in sectors like transport and industry. More sustainable sources could be sought for processes like petrochemicals, industrial painting, and wood furniture. Another promising avenue would be to “optimize the energy structure of motor vehicles”.

Dr. Chao He, lead author of the study, said, “Our findings underscore the critical need for integrated pollution control strategies. By addressing PM2.5 and O3 together, we can more effectively reduce the health risks and environmental impacts associated with these pollutants.”

The authors believe the proposed synergistic control framework offers a promising approach to managing global air pollution.

New data seem to show that only two percent of polluting vans scrapped under the ULEZ scrappage scheme have so far been switched to electric vehicles despite Transport for London (TfL) committing over £100 million in funding to businesses.

TfL reported that of the 16,207 approved applications to scrap a petrol or diesel van between January 2023 to May 2024, only 372 were replaced with an electric vehicle.

The figures were revealed in new analysis from campaign group Clean Cities on 26 June, and during London Climate Action Week as Defra was forecasting the first summer smog of the year in London and southeast England.

In 2023, the Mayor of London launched a ULEZ scrappage scheme to provide financial assistance to help Londoners and businesses scrap the highest polluting vehicles to prepare for the expansion of the ULEZ across all London boroughs.

The scheme provides grant payments to scrap, donate or retrofit vehicles that do not meet the emissions standards and switch to cleaner modes of transport.

Analysis published this week by Transport & Environment, Europe’s leading clean transport group, shows the number of vans on UK roads has increased by over a million since 2014.

The campaigners’ analysis shows carbon emissions from vans in the UK have risen 63 percent since 1990, threatening climate targets despite the growing push for electric vehicle (EV) adoption. Carbon emissions from private cars and taxis have decreased by 19 percent over the same period.

The majority of new van sales are diesel, accounting for 90 percent of all new van sales in 2023.

In contrast diesel cars registered on UK roads have fallen by 13 percent between the end of 2018 and the end of 2023 but diesel vans rose about 13 in that same period

This is reflected in harmful nitrous oxide emission levels in the UK. With emissions from HGVs and cars falling by 91 percent and 88 percent respectively since 1990 but vans have only managed a fall of 38 percent.

Recent polling, commissioned by Clean Cities, has revealed 67 percent of Londoners believe small businesses still need more support to help them switch to electric vehicles.

The survey of 4,000 UK adults also finds that three-in-five (59%) Londoners want their councils to take stronger action against air pollution and protect the environment. Nearly half (46%) also believe delivery vehicles have a negative impact on their local roads.

Campaigning for policy change, Clean Cities is launching Clean Cargo Capital, a campaign focused on accelerating the uptake of electric or pedal powered commercial vehicles in London.

The campaign is calling on Mayor Sadiq Khan to improve incentives for businesses to switch to electric vehicles, such as reviewing and reprioritising the ULEZ scrappage fund and extending the Congestion Charge Cleaner Vehicle Discount for SMEs, ride-hailing, and car-sharing services until late 2027.

The discount is set to be discontinued at the end of 2025, meaning it will cost businesses the same to drive a diesel or electric vehicle in central London, despite electric van sales lagging and diesel being one of the largest contributors to air pollution in this area.

Oliver Lord, UK Head of Clean Cities, said, “The Mayor’s van scrappage scheme is a leading endeavour but something isn’t right if only two percent of businesses in London have ditched diesel and switched to electric instead. Londoners rightly expect businesses to step up and play their part in cleaning the air and protecting the environment but more support is needed to make cleaner electric vans a viable option.

Our polling shows a majority of Londoners believe small businesses should have more support to help them switch to electric vehicles, so it’s puzzling that the Mayor is set to remove the Congestion Charge discount next year.

A newly elected Mayor and a new government offers a unique opportunity to double down and deliver the regulatory certainty, incentives and infrastructure that businesses need so that electric vans become the norm and not a nice to have.”

Ralph Palmer, UK Electric Vehicle and Fleets Officer at Transport and Environment, said: “The continued rise in van emissions in the UK is alarming. Despite the push for more electric vans on our roads, we are still witnessing a surge in greenhouse gas emissions from vans as a result of sustained sales of diesel vans, countering trends we are seeing in the car market.

It’s clear that more action is needed to boost electric van demand among fleets to ensure we achieve the triple-win of tackling emissions, reducing running costs for small businesses and boosting energy security. The new Government should bring forward plans for stronger financial support and action to improve the nation’s charging infrastructure for van drivers to ensure the UK doesn’t continue to fall behind other European countries.”

Edinburgh, no stranger to an occasional haze, experienced an unprecedented atmospheric event on 31 May, unlike any seen over the past 30 years. While sea haar from the North Sea often blankets Scotland’s capital, the haze observed that Friday felt distinctively different. UKCEH researchers are currently investigating if this haze can be attributed to a volcanic plume that transited the UK following an eruption in Iceland.

A new fissure eruption occurred on the Reykjanes Peninsula in Iceland, the fifth eruption in a series that began in December 2023 near the town of Grindavik. Initially deemed a local concern due to its non-explosive nature, the eruption’s impact on UK’s air quality was thought to be minimal. However, meteorological circumstances caused sulphur dioxide (SO₂) levels in Scotland to rocket to levels not witnessed since the 1970s on the morning of 31 May.

The Scottish Environment Protection Agency’s (SEPA) national volcanic emissions network first detected an increase in SO₂ on the Isle of Lewis on the evening of 30 May. During the early hours, the plume moved southward, peaking in Scotland’s Central Belt by 6 am on 31 May. St Leonard’s in Edinburgh reported a maximum concentration of 1161 µg m-3.

Using a combination of observations and modelling data, UKCEH researchers were able to pinpoint the high SO₂ levels, making it highly likely that the increased levels could be attributed to the Icelandic volcano. The UKCEH’s EMEP4UK atmospheric chemistry transport computer model application confirmed the sequence of events, indicating that if the eruption had occurred differently, the SO₂emissions might have missed the UK entirely.

What distinguished this from previous events is that significantly higher concentrations of SO₂ were recorded than previously reported in the UK, surpassing those of previous Icelandic eruptions in recent years. Alongside high SO₂, the volcanic plume comprised a mixture of other gases, our researchers are now investigating the composition of the plume in more detail.

Should we be concerned?
While this event exceeded air quality objectives for 10 hours in Edinburgh, it did not breach workplace exposure limits or pose a significant health risk. Our modelling effort helped predict that this plume would pass rapidly over the UK. Through chemical reactions, sulphur dioxide can contribute to the formation of small airborne particles (PM_2.5) that are harmful to human health. Measurement and model results indicate that PM_2.5 concentrations stayed well below levels of concern during this event.

Ecosystems are also vulnerable to sulphur dioxide. However, again the short-lived nature of the plume means that damage is likely to have been minimal.

This event will give us valuable insights into how well we can predict the impacts of volcanic eruptions on human health and our environment. This helps us both to respond at short notice, and to be prepared for future eruptions.

For further information please see the related blog.