Urban volatile organic compounds (VOCs) are key precursors of tropospheric ozone and secondary organic aerosols (SOA), yet their long-term dynamics and health implications remain unclear across Europe. Here, we synthesize two decades of VOC observations (2002-2023) from 21 urban monitoring sites in six countries to assess emission trends, oxidation potentials, and human exposure risks. Consistent declines in total hydrocarbons were observed at most sites, reflecting the effectiveness of emission control policies. Aromatic hydrocarbons such as toluene, xylene, and benzene were the dominant contributors to ozone and SOA formation. Physiologically based toxicokinetic (PBTK) modeling suggests that key VOCs preferentially accumulate in the kidney and liver. The integration of atmospheric monitoring with toxicokinetic modeling provides a multi-scale understanding of how urban VOCs influence both air quality and internal human exposure, offering new insight into effective pollution control strategies.

Air pollution in cities is a critical environmental and public health concern, where achieving legal limit values and progress towards WHO health-based guidelines may be challenging. Transportation is one of the leading causes of air pollution in urban areas, and hence public transportation systems such as low / zero tailpipe emission buses play a crucial role in reducing toxic emissions to air, and improving sustainable mobility and social connectivity. In addition, as combustion emissions from transport also negatively impact the climate, a move to transportation systems that can be powered using green energy are necessary. Responding to the climate severity and its link to urban air pollution, a global push for sustainable transportation is occurring. This study employed an advanced street scale air quality dispersion modelling system to assess the impact of five hypothetical bus fleet electrification scenarios (i.e. 20 %, 40 %, 60 %, 80 % and 100 % electrification) on the changes to air pollution levels in a UK metropolitan area (West Midlands). Modelled spatial distributions of air pollutant concentrations have been integrated into the West Midlands Air Quality Lifecourse Assessment tool for the assessment of associated air quality related health effects, generating electoral ward level health and economic outcomes. Potential air quality improvements were observed in nitrogen dioxide (NO2) concentration up to 13 μg m-3 (or 27 %), and in PM2.5 (particulate matter with diameter less than 2.5 μm) concentration up to 0.5 μg m-3 (or 4 %). The modest improvements in regional health considering only air quality related impacts on disease incidence (up to 3.1 % in at attributable burden of asthma diagnoses over 10 years) and mortality (up to 0.7 % in deaths prevented over 10 years) were also observed. This study provides evidence for the air quality and health co-benefits of the carbon transportation systems.

Nitrogen-containing organic compounds (NOCs), encompassing a complex suite of oxidized and reduced organic nitrogen species, exert significant impacts on atmospheric light absorption, oxidation capacity, and global nitrogen cycling. Despite the growing recognition of NOCs as key components of atmospheric organic matter, their formation through aqueous-phase processes and potential environmental impacts have long been underestimated. This review begins by summarizing the major classes of NOC molecules, then synthesizes observational evidence on their formation in the aqueous-phase, particularly highlighting its critical role in generating nitroaromatic and N-heterocyclic compounds. Built on the observational evidence, we further discuss the related evaluation of the multi-faceted environmental impacts arising from the aqueous-phase NOC formation. The evidence demonstrates that aqueous-phase NOC chemistry exerts significant influence on atmospheric compositions, contributes up to 90% of brown carbon's radiative effects, enhances oxidative capacity and secondary organic aerosol production, and influences nitrogen speciation in wet deposition. However, most current model assessments exhibit considerable limitations in quantifying these effects, stemming primarily from oversimplified parameterizations of aqueous-phase chemistry that fail to adequately represent the full complexity of atmospheric multiphase systems. Furthermore, existing observational data sets remain insufficient, severely constraining efforts to optimize model parameters and validate simulation outputs. To address these critical knowledge gaps, we propose an integrated research framework that combines long-term monitoring of key NOC and various precursors and advanced simulations of aqueous-phase chemistry at the micrometer-scale reaction environments, which would constrain the parameterization of future models for the aqueous-phase chemistry and impacts of NOCs.

Indoor cooking generates intense, short-duration fine particulate matter (PM2.5) peaks with acute health risks. To quantify the efficacy of natural ventilation configurations, we conducted approximately two months of continuous monitoring in a modern UK one-bedroom apartment, comparing three ventilation scenarios during cooking: fully opened (all windows and internal doors open), door-opened only (internal doors open but windows closed), and fully closed (all windows and internal doors closed). Air quality sensors were calibrated against a reference instrument (Fidas 200E) both before and after the field deployment. During the study period, outdoor PM2.5 mass concentrations ranged from 0.4 to 31.0 μg m-3, averaging 6.3 μg m-3. Indoor concentrations were substantially higher than average outdoor levels, with the fully opened scenario yielding the lowest exposure at 14.9 μg m-3 in the living room/kitchen and 15.4 μg m-3 in the bedroom. Relative to the fully opened scenario, PM2.5 concentrations increased by 58.4% (living room/kitchen) and 55.8% (bedroom) under door-opened only conditions, and under fully closed conditions by 28.9% and 27.9%, respectively. These findings demonstrate that simultaneous opening of windows and internal doors during cooking can substantially reduce acute PM2.5 exposure, offering a simple, low-energy strategy to mitigate short-term health risks in naturally ventilated apartments.

Indoor air pollution during cooking and cleaning is influenced by complex interactions between direct emissions, ventilation-driven outdoor/indoor exchange, deposition and chemical reactions on surfaces, and indoor chemical processing. This study developed a flexible indoor single-box model (SBM-Flex) based on the INCHEM-Py indoor chemistry model to improve the representation of indoor chemistry and pollutant dynamics. The model contains chemical mechanisms of differing complexities, which can be chosen to balance computational efficiency and accuracy for specific applications. SBM-Flex was evaluated against a new observational dataset collected with reference instruments in a residential kitchen to evaluate the model's ability to simulate real-world conditions. The model qualitatively and quantitatively reproduces background conditions and episodic emission events, particularly for NOx, CO, and monoterpenes. We showed that a revised HONO formation scheme, incorporating relative humidity dependence, improves the process-level representation of indoor radical chemistry, resulting in a more realistic HONO, OH and HO2 description compared to a static HONO treatment. Simulated cooking and cleaning events highlight the importance of event-specific emissions and occupant-related effects, particularly enhanced surface deposition due to human presence, which influences O3 removal. Comparison between measurement-informed and inventory-based emissions reveals significant discrepancies, with inventory emissions often, though not uniformly, higher than real-world values. These findings underscore the need for activity-specific emission inventories and improved ventilation representation. SBM-Flex offers a promising approach for indoor air quality modelling providing valuable insights into the key processes that govern pollutant behaviour in residential environments and hence identifying priorities to reduce exposure and protect health.

Isoprene, the globally most abundant volatile organic compound, significantly impacts air quality. Determining isoprene concentration variations and their drivers is a persistent challenge. Here, we developed a robust machine learning framework to simulate isoprene concentrations, without requiring localized emission inventories and explicit chemistry. Temperature, radiation, and surface pressure were the primary drivers of short-term isoprene variations across Chinese cities. On climatic timescales, urban greenspace expansion and climate warming drove isoprene increases by 341 pptv in Hong Kong during 1990-2023, but traffic emission reductions in London counteracted the isoprene rise that climate warming would have otherwise caused (-755 pptv vs. +31 pptv). Driven by rising temperatures and isoprene levels, ozone would increase by up to 1.7-fold by 2100 under the high-emission scenario. However, ambitious reduction in nitrogen oxides would alleviate this growth to 1.2-fold. The study has the potential to inform air quality management in a warming climate.

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.

The formation of cloud condensation nuclei is a critical but uncertain factor in Arctic climate dynamics. A major nuclei contributor is new particle formation, yet the geographical variations in activity and the factors driving it remain poorly understood. Here, we present a nine-year (2010–2018) analysis of atmospheric particle number size distributions from Tiksi, Russia, integrated with air mass trajectory modelling and ocean remote sensing. We show that aerosol formation rates are significantly enhanced—particle formation rates increase by 300

Delhi, one of the world's most densely populated megacities, experiences extreme haze during the Diwali Festival─a nationwide celebration marked by intense fireworks coinciding with postmonsoon biomass burning. Although bulk measurements routinely show sharp PM2.5 spikes during Diwali, direct microscopic evidence linking specific aerosol types to these concurrent sources remains limited. Here, we combined transmission electron microscopy (TEM) with bulk chemical analysis to identify particle types and track their physicochemical evolution throughout the Diwali period. Before Diwali, aerosols were dominated by potassium (K)-rich particles (25%), carbonaceous particles (primary organic aerosol (POA) and soot, 29%), and their internal mixtures (K-POA/soot, 37%), with frequent spherical POA (i.e., tar balls), indicating a strong biomass-burning influence. During Diwali, particle populations shifted abruptly to a pyrotechnic signature of fireworks, characterized by abundant Al2O3 monomers (30-300 nm) and their agglomerates, either as bare (36-40%) or uniformly coated by K2SO4 (Al2O3-K, 46-47%). After Diwali, ultrafine Al2O3 particles (<100 nm) persisted and underwent coagulation with aged biomass-burning particles, forming distinctive Al2O3-K-POA/soot internal mixtures. Therefore, Al2O3 nanoparticles can serve as a tracer of fireworks and were further internally mixed with carbonaceous particles derived from biomass burning during severe haze events of Diwali. These metal-containing particles warrant particular attention because of their potential toxicity and adverse respiratory health effects in the densely populated megacity.

Ambient air pollution remains a leading environmental risk factor for premature mortality and economic loss, particularly in rapidly urbanizing low-and middle-income countries such as Bangladesh, where empirical city-level evidence remains limited. This study aimed to quantify the long-term mortality burden (all-cause and cause-specific cardiovascular, respiratory, and lung cancer mortality) and associated economic costs attributable to ambient PM2.5 in six major cities of Bangladesh between 2013 and 2021. The annual concentrations of ambient PM2.5 from Continuous Air Monitoring Stations (CAMS) of six selected cities (Dhaka, Chattogram, Rajshahi, Sylhet, Khulna, and Barisal) of Bangladesh were used for exposure assessment in this study. The present study applied literature-derived Concentration-exposure-response functions to estimate the all-cause and cause-specific mortality burden linked to PM2.5 among those living in the cities during study period. A valuation of the economic loss attributed to premature mortality was made utilizing the Value of Statistical Life methods. In 2021, the average mortality burden of PM2.5 in the six cities per 100,000 population was 260 (95% CI: 142-370) premature deaths from all causes, 112 (95% CI: 61-160) from cardiovascular diseases, 25 (95% CI: 13-38) from respiratory diseases, and 3 (95% CI: 1-4) from lung cancer. The economic costs for all-cause mortality related to PM2.5 across six cities were estimated to be $23 billion USD ($19.3-$26.7) in 2021. These findings highlight the substantial public health and economic burden of ambient air pollution in urban areas and underscore the urgent need for strengthened air quality management and evidence-based policy interventions.

While air quality has improved in many cities, short-term spikes in urban pollution continue to cause elevated health risks. To mitigate such risks, pollution alerts trigger short-term interventions (e.g. temporary industrial curtailments or shutdowns, on-road traffic restrictions, construction bans with dust control, and public health advisories) to rapidly cut emissions and exposure. However, the effectiveness of such alerts has remained uncertain. Here, we analyzed air quality and weather data from 57 cities across northern China between 2018 and 2022 and used a two-step machine learning chain to predict counterfactual concentrations under a no-alert (no-intervention) scenario. Our findings show that interventions enacted under alerts effectively reduced pollutant concentrations, with particulate matter (PM) decreasing by 20-40% and nitrogen dioxide (NO2) by 5-25% across different cities, reflecting the variability in alert effectiveness among locations. The reduction in PM2.5 is estimated to have prevented nearly 54,000 ± 6,000 (∼11%) premature deaths during the study period. Over 80% of these avoided deaths occurred in regions characterized by heavy industries, high coal consumption, and dense population (e.g. Henan, Hebei, and Shandong), where alert-driven interventions had greater impacts. In contrast, service-oriented cities such as Beijing showed moderate but still measurable PM reductions (∼30 μg m-3) and correspondingly smaller health benefits. These results provide the first multi-year, multi-city evidence that pollution alerts-through the interventions they trigger-deliver significant and repeatable air quality and public health benefits, offering actionable support for short-term response protocols that complement long-term emission controls in cities worldwide.

Nitrate radicals (NO3) are the dominant oxidants at night, shaping air quality, the climate, and ecosystems. However, the vertical variations of NO3 chemistry within the nocturnal boundary layer remain poorly understood, owing to the stratification of air masses and complex vertical chemistry. Here, we combined vertical and ground-based measurements of NO3 precursors from diverse atmospheric environments with model simulations to investigate the vertical structure of nocturnal NO3 oxidation and its long-term trend. Our results indicate that the nocturnal enhanced NO3 chemistry aloft event occurs far more frequently in megacities (64-72%) than in representative clean areas (16%), with a median enhancement factor of 2.7 relative to the surface. The event largely promotes the formation of secondary pollutants aloft rather than at the surface. We further show the event is more prevalent in China and India, attributed to intense ground-level NOx emissions, than in the United States and Europe. However, its frequency has declined rapidly in China in recent years, closely linked to the implementation of NOx emission controls. These findings highlight the critical role of vertical gradients in nocturnal NO3 chemistry on surface air pollution and underscore the need for comprehensive vertical measurements to support further improvement of urban air quality.

Delhi experiences some of the highest levels of fine particulate matter (PM2.5) pollution among megacities worldwide. Here, we integrated radiocarbon (14C) analysis with organic molecular tracers to quantify the sources of carbonaceous aerosols in Delhi. Through time-resolved seasonal and diurnal PM2.5 sampling at two representative urban sites and using 14C as an unambiguous tracer, we provide robust quantitative constraints on source contributions. We found that fossil fuel combustion is the dominant contributor, accounting for 62-65 % of organic carbon and 64-66 % of elemental carbon in PM2.5. Crucially, primary organic carbon from fossil fuels (POCFF) constituted the largest fraction of PM2.5 organic carbon (31-44 %). Its contribution peaked in the post-monsoon season, driven mainly by traffic emissions and coal combustion. Secondary organic carbon from fossil sources (SOCFF), biomass burning (OCBB), and cooking emissions (OCCK) contributed 21-29 %, 10-18 % and 3-7 % of PM2.5 organic carbon, respectively. Furthermore, comparisons with Positive Matrix Factorization (PMF) results suggest that conventional methods may overestimate the biomass burning contribution, underscoring the value of the 14C-based approach for accurate apportionment in this complex environment. This study underscores the critical need to reduce fossil fuel reliance and accelerate the shift toward clean energy infrastructure to effectively combat carbonaceous aerosol pollution in Delhi.

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)

Indoor fine particles (PM2.5) exposure poses significant public health risks, prompting growing use of low-cost sensors for indoor air quality monitoring. However, maintaining data accuracy from these sensors is challenging, due to interference of environmental conditions, such as humidity, and instrument drift. Calibration is essential to ensure the accuracy of these sensors. This study introduces a novel automated machine learning (AutoML)-based calibration framework to enhance the reliability of low-cost indoor PM2.5 measurements. The multi-stage calibration framework connects low-cost field sensors to be deployed with intermediate drift-correction reference sensors and a reference-grade instrument, applying separate calibration models for low (clean air environment) and high (pollution events) concentration ranges. We evaluated the framework in a controlled indoor chamber using two different sensor models exposed to diverse indoor pollution sources under uncontrolled natural ambient conditions. The AutoML-driven calibration significantly improved sensor performance, achieving a strong correlation with reference measurements (R2 > 0.90) and substantially reducing error metrics (with normalized root-mean-square error (NRMSE) and symmetric mean absolute percentage error (sMAPE) roughly halved relative to uncalibrated data). Bias was effectively minimised, yielding calibrated readings closely aligned with the reference instrument. These findings demonstrate that our calibration strategy can convert low-cost sensors into a more reliable tool for indoor air pollution monitoring. The improved data quality supports atmospheric science research by enabling more accurate indoor PM2.5 monitoring, and informs public health interventions and evaluation by facilitating better indoor exposure assessment.

Iron (Fe) plays a crucial role in the global biogeochemical cycle, marine ecosystems, and human health. Despite extensive research on Fe dissolution, the understanding of the mechanism of the Fe acidification process remains highly controversial. Here, we revealed significant differences in Fe acid dissolution between the upper mixing layer and the ground-level of a megacity. The results showed that air masses with elevated n[SO42-] n[NO3-] ratios (5.4 +/- 3.7) yielded more enhanced iron solubility (%Fe-S, 8.7 +/- 2.4 %) in the upper mixing layer after atmospheric aging compared to those (1.6 +/- 0.7 and 3.3 +/- 0.4 %, respectively) at the ground-level near source regions of acidic gases. Further analysis suggested that Fe dissolution is primarily driven by sulfuric acid in the upper mixing layer different from nitric acid at the ground-level, attributing to the aging processes of acidic species during long-range transport. %Fe-S also exhibits a clear size dependence: sulfuric-acid dominates in submicron aerosols (D-p < 1 m), leading to elevated %Fe-S (3.5 +/- 3.9 %), whereas alkaline mineral dust in supermicron particles (D-p > 1 mu m) neutralizes nitric acid and suppresses Fe dissolution (1.8 +/- 2.2 %). This finding highlighted that sulfuric acid dominates Fe acidification process in the upper layer and submicron particles, but the contribution of nitric acid to Fe dissolution at the ground-level is equally important. Our study provides new data sets for testing atmospheric model's capability to simulate dissolved Fe concentration and deposition and will help to improve the accuracy of Fe solubility predictions.

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 (PM2.5 and PM10) concentrations in fan areas around the stadium peaked ahead of the athletics events and opening and closing ceremonies with PM2.5 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 PM2.5 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.

The UK has a legally binding commitment to achieve net-zero greenhouse gas emissions by 2050, and multiple statutory responsibilities related to mitigation actions are held at local or regional authority levels. However, local authorities face multiple political, financial and service pressures. Adopting a “whole-systems approach” which addresses complexity across interrelated sectors is necessary to achieve significant progress and to optimise co-benefits, but systems thinking is not currently formally embedded in local government. Using the West Midlands’ journey to net zero as a case study, this research explores the use of participatory systems mapping with local and regional authority officers to examine the system that would enable ‘thriving, net zero communities in the West Midlands’. Analysis of the systems map, constructed across a workshop and online follow-up sessions, identified opportunities for local and regional authorities to create local benefit whilst delivering on both statutory functions and net zero, by disrupting reinforcing poverty cycles, improving the quality of housing, and increasing skills and employment support. This whole-system approach also highlights the need for different ways of working in local government to facilitate greater cross-team collaboration to address ‘wicked’ problems such as poverty, climate adaptation and resilience.

Subway systems are vital for urban transit, yet their air contains iron-oxide nanoparticles that may threaten commuters' respiratory and cardiovascular health. Despite their prevalence, the microscopic properties, formation mechanisms and health effect of these particles remain poorly understood. Here we analyze subway-derived dust sampled at four sites along three metro lines in Hangzhou, China, revealing that magnetic nanoparticles constitute a substantial fraction of subway aerosols. These particles exist in two forms: alpha-Fe2O3 from surface dust and airborne Fe3O4 nanoparticles with a magnetic core encapsulated in an amorphous SiO2 shell, primarily originating from wheel-rail and brake-wheel friction. Notably, we detect nanoscale Fe3O4 particles in lung tissues of subway commuters, demonstrating their inhalation and pulmonary deposition in humans. Mouse inhalation exposure experiments further confirm that Fe3O4 nanoparticles can induce pronounced lung injury. Our findings highlight friction-derived magnetic nanoparticles as a potential public health risk and underscore the need for strategies to mitigate commuter exposure in urban subway systems.

Mineral dust absorbs and scatters solar and infrared radiation, thereby affecting the radiance spectrum at the surface and top-of-atmosphere and the atmospheric heating rate. While half of the outgoing thermal radiation is emitted in the far infrared (FIR, 15-100 mu m), knowledge of the optical properties and thermal radiative effects of dust is currently limited to the mid-infrared region (MIR, 3-15 mu m). In this study we performed pellet spectroscopy measurements to evaluate the MIR and FIR contribution to dust absorbance and explore the variability and spectral diversity of the dust signature within the 2.5-25 mu m range. Thirteen dust samples re-suspended from parent soils with contrasting mineralogy were investigated, including low and mid latitude dust (LMLD) sources in Africa, America, Asia, and Middle East, and high latitude dust (HLD) from Iceland. Results show that the absorbance of dust in the FIR up to 25 mu m is comparable in intensity to that in the MIR. Also, spectrally different absorption (position and shape of the peaks) is observed for Icelandic dust compared to LMLD, due to differences in mineralogical composition. Corroborated with the few available literature data on absorption properties of natural dust and single minerals up to 100 mu m wavelength, these data suggest the relevance of MIR and FIR interactions to the dust radiative effect for low to high latitude sources. Furthermore, the dust spectral signatures in the MIR and FIR could potentially be used to characterise the mineralogy and differentiate the origin of airborne particles based on infrared remote sensing observations.