Coastal industrial and urban regions in Europe host a substantial fraction of the population and economic activity, yet they remain highly vulnerable to particulate matter (PM) pollution episodes. Despite the implementation of air quality regulations, exceedances of PM10 and PM2.5 concentration thresholds persist, driven by the coexistence of dense emission sources and complex coastal atmospheric dynamics. In this study, pollution days (PDs) were analyzed over a four-year period (2018–2021) in the Greater Dunkirk Area, a coastal region influenced by multiple anthropogenic and marine sources. Spatial analyses indicate that PM2.5 pollution episodes are predominantly associated with regionally extended plumes, whereas PM10 episodes are more frequently linked to locally confined plumes, exhibiting marked seasonal variability. Detailed aerosol chemical characterization was conducted using SEM–EDX analysis on more than 23,000 individual particles collected during a one-year field campaign in 2021. The results reveal a highly heterogeneous particle population, largely dominated by sea-salt and carbonaceous aerosols, with fine particles enriched in secondary sulfur-containing species and coarse particles characterized by calcium-rich components. The particle mixing state index (χ) spans a wide range (0.5–0.9), reflecting a continuum between externally and internally mixed aerosols, strongly modulated by atmospheric ageing processes, pollutant recirculation, and turbulent mixing. Our findings demonstrate that neither local wind direction nor plume spatial extent alone adequately explains the observed chemical variability. Instead, the evolution of aerosol composition and mixing state is governed by fine-scale meteorological processes, including sea-breeze circulations and recirculation events, which critically influence pollutant dispersion and ageing. These results underscore the importance of integrating high-resolution single-particle chemistry with urban-scale meteorological dynamics in air quality assessments, particularly in complex coastal environments subject to multiple emission sources.

Indoor air pollution constitutes a public health problem due to the long time that individuals spend in enclosed spaces every day. The present study aims to investigate the level of volatile organic compounds (VOCs) in indoor air in households in Senegal, and to assess health risks related to residents’ exposure. Of the 17 VOCs identified, 16 were detected in Medina accommodations versus 14 in Darou Khoudoss. Toluene levels reached 70.9 μg/m3 in Medina and 18.5 μg/m3 in Darou Khoudoss, which were the highest compared to other compounds. The sum of Benzene, Toluene, Ethylbenzene, o-Xylene, and 1,2,4-trimethylbenzene concentrations were two times higher in Medina (79.57 µg/m3 versus 37.1 µg/m3). Furthermore, VOCs were found at higher levels in living rooms compared to other living spaces. The highest benzene and acetone concentrations were estimated at 13.6 µg/m3 and 8.4 µg/m3, respectively, in households where incense was burnt daily, while the highest formaldehyde levels were observed in households using incense seasonally (6.8 µg/m3). As regards the health risks associated with exposure of residents, the lifetime cancer risks were all above the WHO tolerable limit (10−5–10−6). Exposure to benzene (8.5 µg/m3) associated with a lifetime risk of leukemia (51.3 per million people exposed) was higher in Darou Khoudoss, while the risk of nasopharyngeal cancer (600 per million people exposed) associated with exposure to formaldehyde (4.23 µg/m3) was higher in Medina.

This study is the first in a coastal West African country to evaluate the histopathology, condition index and stress-on-stress response time of caged brown mussels Perna perna for use in pollution monitoring of coastal ecosystems. Perna perna collected from an unpolluted area on the coast of Senegal were divided and transplanted to a polluted site or maintained at the reference site for an exposure-depuration experiment. After 4 weeks of exposure, the mussels deployed at the polluted site (Port of Dakar) were then transferred to the cleaner reference site (Pointe des Almadies) for depuration. Mussels exposed to the polluted waters of the seaport had bioaccumulated polycyclic aromatic hydrocarbons (PAHs) as well as lead, copper and selenium; furthermore, changes were observed in their digestive gland histology, and their stress-on-stress response measured as median survival time (LT50) had decreased. By the end of the 4-week depuration period at the reference site the mussels showed signs of recovery, specifically in terms of their digestive tubule architecture and tolerance to air exposure. The results demonstrate that caged P. perna could be used as bioindicators for monitoring coastal environmental pollution in West Africa.

Phytomanagement integrates optimized phytotechnology to mitigate soil toxicity risks with a valorization strategy for the biomass produced on the contaminated soil. This three-year in situ study explores an innovative high-value-added chain by cultivating angelica (Angelica archangelica L.), an aromatic plant, on aged trace element (TE)-contaminated soil to produce essential oils (EO). Our results show that angelica thrived on heavily TE-contaminated soil, yielding up to 1.9 kg/ha of EO. Analyses of TEs and pesticide residues confirmed that EO distilled from angelica seeds contained negligible pollutants below or near detection limits and was similar to commercial EO. While fungal biomass remained unaffected, vegetation significantly increased total soil bacterial biomass and metabolic potential compared to initial conditions. Although mycorrhizal inoculation did not enhance angelica biomass yields, it significantly increased the plant's mycorrhizal colonization rate and contributed to reducing soil ecotoxicity after three years of cultivation. Moreover, a social acceptability study indicated that EO production from angelica seeds grown on heavily TE-polluted soil was well received by the public. The sector's positive economic balance further highlights its strong potential for development within phytomanagement strategies.

An instrument based on cavity-enhanced Faraday rotation spectroscopy (CE-FRS) operating at 2.8 mu m has been developed for interference-free measurement of OH radicals in the laboratory. By off-axis coupling of a continuous-wave laser into a high finesse optical cavity, FRS signal is obtained from balanced detection of time-integrated light intensity leaking out of the cavity in the presence of magnetic field. Radio-frequency white noise (5-520 MHz) was injected into laser current which reduced intensity fluctuations in cavity transmission, thus improved the signal-to-noise ratio of the spectroscopic signal by a factor of 2. The setup provides a simple and robust spectroscopic instrument for in-situ and highly-selective detection of paramagnetic species. We demonstrated the instrument's capabilities using OH radical with concentration in the range of 10(12) molecule.cm(-3), generated by microwave discharge of water vapor at low pressure. The CE-FRS instrument exhibited a limit of detection of similar to 10(10) molecule.cm(-3) in an integration time of 20 s, which is enhanced by a factor of 2.5 compared to cavity-enhanced wavelength modulation spectroscopy involving an off-axis integrated cavity output spectroscopy approach. A time-resolved FRS signal was recorded in a pulsed microwave discharge regime, giving a millisecond time resolution for the measurement of OH concentration profile. The developed instrument provides a potential analytical tool for the measurement of OH concentration for chemical kinetic study in reactor cells.

In the current energy context, pallet boards represent a wood of opportunity strongly used on an individual scale as a means of heating at a low cost. However, French stoves are certified to burn only hardwood species. The main objective of this work is to study the combustion behavior of pallet boards in a commercial stove designed to burn hardwood. The novelty of this work lies in the study of the influence of the wood surface exposed to fire and the identification of the conditions that promote the production of ultrafine particles. The results of the combustion tests show that the surface exposed to the fire influences the combustion. Of the six wood dispositions tested, two stand out with gaseous and particulate emissions at similar levels of a conventional hornbeam log and a densified log. Low temperature conditions and high levels of unburned gaseous products were identified as promoters of ultrafine particles. Overall conclusion of the study is that it is possible to use pallets in a non-designed stove, provided that the user carefully manages the combustion. This opens the way to the clean and rational use of a new type of fuel in a low carbon circular economy.

Coloured pyrotechnic smokes are frequently used in the military field and occasionally by civilians, but their health hazards have been little studied. The main concern could rise from inhalation of smoke particles. Our previous study showed that acute exposure to particles from a red signalling smoke (RSS) induced an antioxidant and inflammatory responses in small airway epithelial cells. The aim of this study was to further explore the toxicity of RSS particles at a more proximal level of the respiratory tract, using normal human bronchial epithelial cells grown at the Air-Liquid Interface. Acute exposure (24 h) induced an oxidative stress that persisted 24 h post-exposure, associated with particle internalization and epithelium morphological changes (cuboidal appearance and loss of cilia). Repeated exposures (4×16h) to RSS particles did not trigger oxidative stress but cell morphological changes occurred. Overall, this study provides a better overview of the toxic effects of coloured smoke particles.

Filter-free measurement of light absorption properties of brown carbon has been performed in the CESAM simulation chamber using a photoacoustic spectrophone operating at 405 nm.

There is a scarcity of model species for contaminant monitoring in Africa meanwhile several studies have reported cases of pollution by numerous chemical contaminants. The aim of this study was to evaluate the use of one possible model species, the filter-feeding coastal bivalve Perna perna, for contaminant monitoring. P. perna collected from an unpolluted area of the Senegalese coast were transplanted to the Dakar harbour and to a reference location in the open coast in the vicinity of Dakar. Mussels were retrieved after four weeks’ deployment and either analysed immediately or allowed to depurate for another four weeks. Mussels were analysed for biomarkers (selected transcripts and cellular responses) in gills and digestive gland (hepatopancreas), as well as for whole body residues of polycyclic aromatic hydrocarbons (PAHs) and metals. Mussels held in the harbour had accumulated both PAHs and the metals Pb, Cu and Se. Transcripts of biotransformation enzymes were downregulated whereas transcripts for antioxidant enzymes were upregulated in the gills compared to those of mussels held at the reference location. Digestive gland acetylcholinesterase and lactate dehydrogenase enzymatic activities were decreased compared to mussels from the reference location. Following depuration, gill transcripts had returned to baseline level except for gill glutathione S-transferase and lactate dehydrogenase activity, which decreased. Acetylcholinesterase inhibition was less prominent following depuration, but still significantly inhibited. The results suggest that caging of P. perna and measurement of selected biomarkers can be used to monitor effects of coastal environmental contamination.

Compact and robust laser spectroscopic instrument operating at 2.8 mu m has been developed for direct measurement of OH radicals without chemical conversion. Two measurement configurations, off-axis integrated cavity output spectroscopy (OA-ICOS) and wavelength modulation enhanced OA-ICOS (WM-OA-ICOS), integrated in a single instrument were implemented. The OA-ICOS approach allowed self-calibration of OH concentration measurement via direct absorption scheme, while wavelength modulation allows us to further improve the detection sensitivity by a factor of similar to 4. Limit of detections of 10.0 x 10(10) and 2.5 x 10(10) molecule cm(-3) were achieved for the OA-ICOS and the WM-OA-ICOS approaches, respectively, with an integration time of 20 s

A panel of twenty commercial briquettes representative of the French market was set up with the different actors of the French densified log industry. The selected briquettes were characterized via the determination of their water and ash content, their ultimate and elemental composition and their heating value. Pollutant emission factors during the combustion of the briquettes were evaluated in real conditions in a domestic stove with natural draught. Gaseous pollutants like CO, CO2, NOx, SO2 and THC (Total HydroCarbons) were monitored. Particulate emissions in mass (TSP) and number (PM2.5) were also measured. Briquettes characterizations showed that the majority of the data determined in laboratory are in agreement with the one announced by the producers. Moreover several briquettes are in agreement with limitation established by the EN ISO 17225 standard. Combustion tests showed that the use of densified fuel instead of traditional log does not lead to a significant degradation of the environmental performances of the stove. Some briquettes present emission factors close to the one measured with traditional wood log. Several recommendations concerning briquettes characteristics were drawn from this study.

As the population grows and the demand for water rises, the development of efficient and sustainable water purification techniques is becoming increasingly important to ensure access to clean and safe water in the future. The pollution of surface and groundwater by nitrate (NO3-) is a growing global concern due to the rise in nitrogen-rich waste released from agriculture and industry. The removal of nitrate ions from aqueous media using bimetallic catalysts loaded on several supports was studied. Multiwalled carbon nanotubes, activated carbon, titanium dioxide, titanium dioxide/multiwalled carbon nanotubes, and Santa Barbara Amorphous-15 were used as supports to synthesize these bimetallic catalysts. The effects of the support type, supported metal, and catalyst reduction method on the nitrate reduction activity in water were investigated. The catalysts were characterized by X-ray diffraction, fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller isotherm, inductively coupled plasma spectroscopy, and field emission gun scanning transmission electron microscope. In terms of nitrate conversion, high-temperature hydrogen reduction of the catalysts was a more effective method of catalyst preparation than NaBH4 reduction. Except for the carbon nanotube-TiO2 composite, pH fixation using CO2 flow improved the efficiency of supported catalysts. The catalysts 1Pd-1Cu/TiO2 and 1Pd-Cu/SBA-15 presented the highest catalytic activity, but the latter was the most selective to nitrogen.

PM2.5 and PM>2.5 samples were collected in Cotonou (Benin) using high volume cascade impaction air samplers. The samplings were based on continuous collection over twelve days. Physical and chemical characteristics of samples were determined by size distribution (laser granulometry), specific surface areas (BET method), inorganic elements (ICP-MS), water-soluble ions (IC), CHNS analysis and organic compounds (GC-MS). Average concentrations of air particulate matter were 180.9 µg/m3 and 94.5 µg/m3 in PM2.5 and PM>2.5, respectively. The higher water-soluble ions recorded were Ca2+,SO42−,NO3−, Na+ and Cl− for both PM. Moreover, concentrations were almost two-fold higher for PM2.5 compared to PM>2.5, with 10.7 µg/m3 of total metals found in PM2.5 versus 5.6 µg/m3 in PM>2.5. Both PM samples under study presented similar repartition of elements considering their percentages. Results suggested that PM>2.5 samples contain agglomerates of fine particles. Identification tools of major pollution source as inorganic elements, paraffins, fatty acids ratios and PAHs ratios indicated that PM under study originated from traffic exhaust.

Nitrate from the application of nitrogen-based fertilizers in intensive agriculture is a notorious waste product, though it lacks cost-effective solutions for its removal from potential drinking water resources. Catalytic reduction appears to be a promising technique for converting nitrates to benign nitrogen gas. Mesoporous silica SBA-15 is a frequently used catalyst support that has large surface areas and highly ordered nanopores. In this work, mesoporous silica SBA-15 bimetallic catalysts for nitrate reduction were investigated. The catalyst was optimized for the selection of promoter metal (Sn and Cu), noble metal (Pd and Pt) and loading ratios of these metals at different temperatures and reduction conditions. The catalysts prepared were characterized by FT-IR, N2 physisorption, XRD, SEM, and ICP. All catalysts showed the presence of cylindrical mesoporous channels and uniform pore structures that remained even after metals loading. In the presence of a CO2 buffer, the catalysts 4Pd-1Cu/SBA-15 and 1Pt-1Cu/SBA-15 reduced at 100?C under H2 and 1Pd-1Cu/SBA-15 reduced at 200°C under H2 demonstrated very high nitrate conversion. Furthermore, the forementioned Pd catalysts had higher N2 selectivity (88% - 87%) compared to Pt catalyst (80%). Nitrate conversion by the 4Pd-1Cu/SBA-15 catalyst was significantly decreased to 81% in the absence of CO2.

We report on real-time and on-field NH3 remote sensing based on a 100 Hz wavelength modulated optical parametric oscillator. Concentrations between 85 and 350 ppm were measured at a distance of ten meters.

Pyrotechnic smokes are widely used in civilian and military applications. The major issue arise from the release of particles after smoke combustion but the health risks related to their exposure are poorly documented whereas toxicity of airborne particles on the respiratory target are very well known. Therefore, this study aimed to explore the in vitro toxicity of the particle fraction of different pyrotechnic smokes.Particles from a red signalling smoke (RSS), an hexachloroethane-based obscuring smoke (HC-OS) and an anti-intrusion smoke (AIS) were collected from the cloud. RSS particles displayed the highest organic fraction (quinones and polycyclic aromatic hydrocarbons) of the three samples characterized. AIS particles contained K and cholesterol derivatives. HC-OS particles were mainly metallic with very high concentrations of Al, Fe and Ca. Intrinsic oxidative potential of smoke particles was measured with two assays. Depletions of DTT by RSS particles was greater than depletion obtained with AIS and HC-OS particles but depletion of acid ascorbic (AA) was only observed with HC-OS particles. In vitro toxicity was assessed by exposing human small airway epithelial cells (SAEC) to various concentrations of particles. After 24 h of exposure, cell viability was not affected but significant modifications of mRNA expression of antioxidant (SOD-1 and -2, catalase, HO-1, NQO-1) and inflammatory markers (IL-6, IL-8, TNF-α) were observed and were dependent on smoke type. Particles rich in metal, such as HC-OS, induced a greatest depletion of AA and a greatest inflammatory response, whereas particles rich in organic compounds, such as RSS, induced a greatest DTT depletion and a greatest antioxidant response.In conclusion, the three smoke particles have an intrinsic oxidative potential and triggered a cell adaptive response. Our study improved the knowledge of particle toxicity of pyrotechnic smokes and scientific approach developed here could be used to study other type of particles.

Volatile Organic Compounds (VOCs) are known to be hazardous and harmful to human health and the environment. In mixtures or during repeated exposures, significant toxicity of these compounds in trace amounts has been revealed. In vitro air-liquid interface approaches underlined the interest in evaluating the impact of repeated VOC exposure and the importance of carrying out a toxicological validation of the techniques in addition to the standard chemical analyses. The difficulties in sampling and measuring VOCs in stationary source emissions are due to both the complexity of the mixture present and the wide range of concentrations. The coupling of VOC treatment techniques results in efficient systems with lower operating energy consumption. Three main couplings are outlined in this review, highlighting their advantages and relevance. First, adsorption-catalysis coupling is particularly valuable by using adsorption and catalytic oxidation regeneration initiated, for example, by selective dielectric heating. Then, several key aspects of the plasma catalysis process, such as the choice of catalysts suitable for the non-thermal plasma (NTP) environment, the simultaneous removal of different VOCs, and the in situ regeneration of the catalyst by NTP exposure, are discussed. The adsorption-photocatalysis coupling technology is also one of the effective and promising methods for VOC removal. The VOC molecules strongly adsorbed on the surface of the photocatalyst can be directly oxidized by the photogenerated hole on the photocatalyst (e.g., TiO2).

The cultivation of coriander (Coriandrum sativum L.) destined for essential oils production was recently presented as an innovative and economically viable alternative for the phytomanagement of trace elements (TE)-polluted soils. However, Cd accumulation in shoots has proven to be an obstacle in the valorization of the distillation residues and the development of these phytotechnologies. The present study aimed to evaluate the effect of arbuscular mycorrhizal fungus (Funneliformis mosseae) inoculation and organic amendment application on the soil TE bioavailability and plant uptake, as well as on the soil quality and health improvement. The application of compost and sewage sludge improved the growth of coriander and Cd and Zn immobilization in soil, resulting in reduced Cd plant uptake. A synergistic effect of arbuscular mycorrhizal fungi (AMF) inoculation and organic amendments was observed in the decrease in the extractable soil Cd and Zn concentrations, but not in the Cd plant uptake. Despite a significant decrease in Cd accumulation in shoots, coriander retained its accumulative phenotype, with a metal bioconcentration factor close to 1. Furthermore, both the vegetation and the organic amendments improved the soil quality and health by increasing its microbial biomass, as estimated by phospholipid fatty acids, soil enzyme activities (dehydrogenase, phosphatase, β-glucosidase, and cellubiosidase), and the bacterial metabolic function and diversity. The findings demonstrate the potential of C. sativum, particularly in combination with organic amendments and AMF inoculation, for the phytomanagement of TE-polluted soils and soil quality and health improvement.