William James Bloss

Electric vehicles (EVs) may improve urban air quality by eliminating tailpipe emissions. Their uptake, however, remains constrained by range anxiety, drivers' concern that the vehicle may not have enough charge to reach a destination or find a suitable charge point. The range capability of electric vehicles can be affected by extreme weather events. Floods can disrupt their charging infrastructure and block access routes. This study proposes a decision-support dashboard named CLEETS-SMART, for South Wales in the United Kingdom. CLEETS-SMART integrates heterogeneous data sources, including the UK National ChargePoint Registry, Welsh Government flood risk layers, and 24-hour weather forecasts from the Open-Meteo API. Users can specify their trip origin, destination, and battery state-of charge (SOC); the dashboard then simulates routes, highlights exposure risks, and recommends safe charging stops. Two routing modes (RCSP and OSRM) are supported which provide charge-feasible routes that minimize total trip time by shortening driving time, avoiding flooded links, and limiting charging duration.

Present-day road transportation is largely fueled by traditional fossil fuels and has unintended adverse effects through emissions of greenhouse gases, anthropogenic heat, and air pollutants, thereby affecting heat, air quality and public health. A thorough assessment of current environmental and health burdens helps clarify how future transport strategies could improve outcomes. Here, four case studies are presented – greenhouse gas emissions in the UK, anthropogenic heat emissions in Chicago (US), air pollutant emissions in Indian megacities, and air pollutant concentrations and associated health burden in the West Midlands (a major metropolitan area in the UK). By examining diverse regions worldwide, this chapter highlights that while mitigating road transportation impacts is a global challenge, its influence on emissions, air quality, heat waves, and public health is shaped uniquely by regional challenges and policy outcomes, and so addressing this requires region-specific targeted interventions.

Cities need computationally efficient, trustworthy ways to evaluate the environmental impact of (cleaner) travel options without running a full climate-and-chemistry model each time. ClimBridge pairs a trusted simulator with a physics-aware surrogate, enabling transport planners to explore multiple “what-if” questions over a significantly shorter time frame than running more complex, computationally intensive models. e describe the trade-offs between the accuracy of model outcomes and computational complexity, helping to address challenges related to uncertainty and novel decision metrics. The role of utilising machine learning to develop surrogate models in this context is highlighted.

New particle formation is an important source of Arctic atmospheric particles and cloud condensation nuclei, yet their precursor sources and molecular-level mechanisms remain poorly understood. Here we report comprehensive ship-based observations from 19 May to 26 June 2022 from southeastern to western Greenland and into the Davis Strait’s marginal ice zone to investigate sources and processes controlling atmospheric particles and cloud condensation nuclei. Our observations provide field evidence of frequent nucleation events driven by the multicomponent iodine oxoacid and sulfuric acid mechanism recently identified in laboratory studies. Newly formed particles grew rapidly beyond 20 nm on 8 out of 13 nucleation days, mainly driven by oxygenated organic molecules from aldehyde and monoterpene oxidation. We also report a previously unobserved class of iodine-containing oxygenated organic molecules that contributed to particle growth and enhanced cloud condensation nuclei formation. We show that marginal sea ice zone produces precursors that drive rapid new particle formation and enhance cloud condensation nuclei concentrations by up to 50-fold. Our findings demonstrate that Arctic iodine, sulfur and organic precursors can enhance cloud condensation nuclei abundance through new particle formation, highlighting a potential but unquantified pathway for influencing cloud cover, radiative balance and the hydrological cycle.

Organosulfates (OSs) form a significant component of secondary organic aerosol (SOA) in the atmosphere. Previously, their measurement using reversed-phase liquid chromatography–high-resolution mass spectrometry (RPLC–HRMS) has led to poor retention and significant matrix effects. Hydrophilic interaction liquid chromatography (HILIC) provides improved retention of polar OSs, such as those formed from isoprene oxidation, and reduced matrix effects. Studies employing HILIC predominantly use gradient elution to separate OSs with varying polarities. HILIC, however, is very sensitive to changes in the water layer within the column, which facilitates separation, meaning the column needs to be thoroughly equilibrated before each injection, significantly increasing analysis time, cost, and solvent waste. The work presented here describes the development of an isocratic HILIC method to analyze OSs in complex ambient PM2.5 samples. This new method significantly reduces solvent usage and analysis time, which is vital for the analysis of large quantities of samples. The method was first validated with synthesized isoprene-derived OS tracers (iOS) and commercially available standards, then applied in the iOS analysis of filter samples collected during the summertime in Manchester, England. Eight filter samples were taken each day, allowing the temporal evolution of iOS tracers to be elucidated. For 336 ambient samples analyzed in this work, the adoption of the isocratic method resulted in a total time saving of 61 h and reduced organic solvent usage by 1.68 L. The targeted analysis of iOS was quantified using authentic standards. Five 2-methyltetrol OS isomers were quantified (C5H12O7S; MTOS_1–4, 6) averaging 0.36, 0.11, 1.25, 2.12, and 0.17 ng m–3, respectively. The average concentration of total 2-methyltetrol OS was 3.99 ng m–3, and 2-methylglyceric acid OS (C4H8O7S: MGOS) was 1.07 ng m–3.

Terpenoids are volatile organic compounds (VOCs) with chemical structures of C5nH8n. Models estimate that the biosphere directly emits approximately 600 Tg terpenoids into atmosphere annually.1 Once released, these compounds undergo oxidation reactions with O3 and OH; leading to the formation of secondary organic aerosols (SOA), which can impact cloud formation and Earth’s albedo.2 Whilst observations show that modelled future increases in atmospheric CO2 will suppress isoprene (C5H8) emissions, the impact on the emission of larger terpenoids such as monoterpenes (C10H16) and sesquiterpenes (C15H24) vary between studies.3 Furthermore, not only do larger compounds (particularly sesquiterpenes), often go unidentified in forest VOC studies,4 these compounds also have limited measurements for their reaction rate coefficients with OH and O3, adding uncertainty to the impact of these emissions on atmospheric oxidative capacity.5 We present a study carried out at a forested Free Air Carbon Dioxide Enrichment (FACE) site at the Birmingham Institute for Forest Research. Here, mature 150-year-old Quercus robur (pedunculate oak) trees have been exposed to elevated CO2 treatment at 150 ppm above ambient for a prolonged 8 year period. We deployed a Proton-Transfer-Reaction Mass-Spectrometer (PTR-MS) to quantify biogenic VOCs emitted under both ambient and elevated CO2 (410 ± 10 and 560 ± 20 ppm CO2 respectively). Measurements of ozone reactivity (kO3) were also carried out using the homebuilt Total Ozone Reactivity System (TORS).6 Our results show a decrease in the emission of C5H8 under elevated CO2, but an increase in the emission of larger, more reactive C15H24 compounds; which drive a doubling in the kO3 measured. This is in contrast to some model assumptions that elevated CO2 will decrease all reactive VOC emissions.

Poor air quality is one of the largest environmental threats to human health, with a broad range of pollutants contributing to air pollution. Of these, fine particulate matter, defined here as particles with an aerodynamic diameter of less than 2.5 micrometres (PM2.5), is especially important with respect to human health. Globally, exposure to ambient PM2.5 is estimated to cause 4.2 million early deaths a year (WHO, 2024) and in the UK 30,422-42,640 early deaths were attributable to ambient PM2.5 exposure in 2018 (Flower et al., 2025).PM2.5 is emitted from a broad range of primary sources and secondary aerosol is formed in the atmosphere from gaseous precursors. In the UK wood smoke from domestic heating has been shown to be an important source of PM2.5 in urban areas, accounting for 20% of annual average PM2.5 mass and up to 50% of PM2.5 mass in the winter heating season (Srivastava et al., 2025). This has led to policy interventions designed to reduce the emission of PM2.5 from domestic combustion. To ensure policy is led by evidence, the source locations and communities exposed to PM2.5 from wood burning need to be better understood.Here, the spatial distribution of PM2.5­ from wood burning was investigated in the West Midlands, the third largest conurbation in the UK. Black carbon concentrations were determined using an aethalometer mounted in a car and the Aethalometer model (Sandradewi et al., 2008) was used to estimate PM2.5 from wood smoke in the winter heating season. Large spatial variations in PM2.5 from wood smoke were observed and combining these measurements with socio-economic data shows that deprived communities are exposed to the highest concentrations of PM2.5­ from wood burning. However, once population density is considered the data suggest that emissions per household may be higher in less deprived areas. ReferencesFlower G, Schneider R., Exley K., Mitsakou C., Masselot P. and Gasparrini A.: Mortality impacts of long-term PM2.5 and NO2 exposure in Great Britain under national and international air quality limits. Atmospheric Pollution Research, https://doi.org/10.1016/j.apr.2025.102827Sandradewi J., Prevot A.S.H., Szidat S., Perron N., Rami Alfarra M., Lanz V.A., Weingartner E., and Baltensperger U.: Using aerosol light absorption measurements for the quantitative determination of wood burning and traffic emission contributions to particulate matter, Environ. Sci. Technol., 42, 33163323, 2008Srivastava D., Saksakulkrai S., Acton W.J.F., Rooney D.J., Hall J., Hou S., Wolstencroft M., Bartington S., Harrison R.M., Shi Z., Bloss W.J.: Comparative receptor modelling for the sources of fine particulate matter PM2.5 at urban sites in the UK, Atmos. Environ., 343, 2025World Health Organisation (WHO): Ambient (Outdoor) Air Pollution, 2024. Available at: https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health (Last accessed 18th Dec 2025)

Road transportation is a major contributor to multiple health-harming air pollutants in India, but exclusive focus on fine particulate matter (PM2.5) pollution and premature mortality along with reliance on global emission inventories that lack detailed national information has undermined contribution of this sector. Here, we examine the influence of Indian road transportation on air pollution and public health using the global Community Emissions Data System (CEDS) emissions inventory and the recently developed national Air Quality, Emission Inventory and Modelling (AEIM) inventory for 2019. The AEIM inventory uses high-resolution activity data and technology-specific emission factors to accurately represent the realistic magnitude and spatial heterogeneity in road transportation emissions across India. Both inventories are used to drive the state-of-art atmospheric chemistry model GEOS-Chem at high spatial resolution (~30 km), and AEIM outperforms CEDS when compared to the quality-controlled ground-based observations from India’s extensive air quality monitoring network. We find that CEDS road transportation emissions are linked to population-weighted mean concentrations (or exposures) of 3.3 µg m-3 of PM2.5, 1.4 ppb of nitrogen dioxide (NO2), and 3.5 ppb of maximum daily 8-hour running-mean ozone (MDA8 O3), the metric associated with health risk. Exposures using the robust AEIM inventory are 66-223% higher: 10.6 µg m-3 of PM2.5, 4.0 ppb of NO2, and 5.8 ppb of MDA8 O3. While road transportation PM2.5 is highest in the Indo-Gangetic Plain, we find that contribution of road transportation to other health-harming pollutants is not necessarily co-located. NO2 hotspots are over major cities and transportation corridors and those for MDA8 O3 are in central and south India, indicating additional health burdens in these regions. Using the AEIM-driven model output and considering diverse pollutants and health impacts, we estimate 10.8 million disability adjusted life years (DALYs) from road transportation-related air pollution in India, five times that associated with previously estimated CEDS-driven road transportation PM2.5 mortality and exceeding that attributed to cigarette smoking in India by 27%. Uttar Pradesh in the Indo-Gangetic Plain has the greatest health burden across all adverse outcomes but the rankings for other states vary by pollutants and health outcomes. Our assessment not only quantifies the magnitude of underestimation but also highlights states that emerge as key contributors to the health burden, providing actionable insights for evidence-based mitigation strategies.Funded by the UKRI-NSF Clean Energy and Equitable Transportation Solutions (CLEETS) project.

Large scale sporting and cultural events attract many spectators to a single site, leading to changed emissions and potentially creating local air pollution hot spots. Here, we monitored the air quality during the Birmingham 2022 Commonwealth Games, held from July 28th to August 8th, 2022, with 323,000 spectators attending the athletics events, including during the opening and closing ceremonies at the (open air) Alexander Stadium in Birmingham, UK. Particulate (PM_2.5 and PM₁₀) concentrations in fan areas around the stadium peaked ahead of the athletics events and opening and closing ceremonies with PM_2.5 concentrations up to 10 times higher than at nearby urban background monitoring stations. For a spectator attending a full day of events at Alexander Stadium, this would represent a 125% increase in their exposure to PM_2.5 relative to the urban background. Nonrefractory particulate composition in these periods was dominated by organics. Four factors were identified from Positive Matrix Factorization (PMF) analysis of particle composition data recorded using a Quadrupole Aerosol Chemical Speciation Monitor (Q-ACSM): two representing cooking aerosol accounting for 71% of the total PM mass during the athletic sessions demonstrating that cooking sources were responsible for the majority of particulate pollution at the venue. The high particulate concentrations at this venue were driven by fast food production at temporary concession stands, common across many large events, leading to a large increase in particulate matter exposure for staff and visitors.