The UK may be required to expand its bioenergy production in order to make a significant contribution towards the delivery of its ‘net zero’ greenhouse gas emissions target by 2050. However, some trees grown for bioenergy are emitters of volatile organic compounds (VOCs), including isoprene and terpenes, precursors in the formation of tropospheric ozone, an atmospheric pollutant, which require assessment to understand any consequent impacts on air quality. In this initial scoping study, VOC emission rates were quantified under UK climate conditions for the first time from four species of eucalypts suitable for growing as short-rotation forest for bioenergy. An additional previously characterised eucalypt species was included for comparison. Measurements were undertaken using a dynamic chamber sampling system on 2-3 year-old trees grown under ambient conditions. Average emission rates for isoprene, normalised to 30 °C and 1000 μmol m⁻² s⁻¹ PAR, ranged between 1.3 μg C gdw⁻¹ h⁻¹ to 10 μg C gdw⁻¹ h⁻¹. All the eucalypt species measured were categorised as ‘medium’ isoprene emitters (1–10 μg C gdw⁻¹ h⁻¹). Total normalised monoterpene emission rates were of similar order of magnitude to isoprene or approximately one order of magnitude lower. The composition of the monoterpene emissions differed between the species and major compounds included eucalyptol, α-pinene, limonene and β-cis-ocimene. The emission rates presented here contribute the first data for further studies to quantify the potential impact on UK atmospheric composition, if there were widespread planting of eucalypts in the UK for bioenergy purposes.

In Turkey, Southeastern Anatolia region is the highest in terms of solar radiation level. However, the provinces in the region are subject to Particulate Matter (PM) coming from the Sahara desert, the Syrian Desert and the Arabian Desert by atmospheric transport. The daily limit of PM₁₀ and PM₂.₅ set by WHO for health is often exceeded in Sanliurfa. PM₁₀ and PM₂.₅ pollutants also accumulate on the Photovoltaic (PV) panels and cause loss of PV panel performance. In this study, the effects of atmospheric dust deposition on the performance of PV panel was determined for both monocrystalline and polycrystalline technologies under Sanliurfa atmospheric conditions. Two panels with the same characteristics were used for each PV panel group from 2 different PV technologies. One of the panels in the group was cleaned by washing with distilled water every Monday while the other was not cleaned. Thus, the effect of the dust accumulation on the PV panel was determined by comparison to the cleaned PV panel. PV panel power is measured with I–V meter. Panel surface temperature, solar radiation and other meteorological parameters are measured simultaneously. The measurements were done every Monday, Wednesday and Friday at 12:00 am from May 1 to December 31, 2019. It is observed that the dust accumulation reduces the PV power output up to 8% depending on the amount of radiation. During the summer months, the power loss on the average is 4.33% for monocrystalline and 4.57% for polycrystalline. In the autumn months, it is less than 1.77%.

This study investigates the contents, distribution patterns, and sources of lanthanoid elements (La to Lu) in aerosols with an aerodynamic diameter ≤10 μm (PM₁₀) in a coastal Caribbean region in order to better constrain the origin of the atmospheric PM contamination. We sampled and analysed PM₁₀ aerosols during 2015 simultaneously at a rural and an urban site in Cienfuegos (Cuba) as well as particles samples from regional contamination sources. Results showed that the sum of the studied lanthanoids concentrations ranged from 0.03 to 13.42 ng m⁻³ and from 0.51 to 18.75 ng m⁻³ at the rural and the urban site, respectively. Time variations for the lanthanoid concentrations displayed similar trends and showed that the highest concentrations corresponded to the influence of the African dust for both sites, but presented distinct variability and lower concentrations when dust intrusions were less frequent. The lanthanoid distribution patterns in the rural and urban sites were significantly different, due to the impact of different local combustion sources. Our results were comforted by comparing the degree of fractionation of the lighter and heavier lanthanoids and the δEu and δCe anomalies between our PM₁₀ samples and those of the local sources of contamination. Ultimately, we highlight the added value of lanthanoid elements as reliable indicators for discriminating emission sources and for tracking the origin of atmospheric particulate matter.

In this paper, we investigate the footprint of the operation of Athens International Airport in loads of air pollutants emitted during the Landing-Take Off phase of incoming and outgoing flights. This part of the flight has the distinctive characteristic that it operates in the human environment, at low altitudes, so it directly affects the air quality at the airport and its surroundings by changing the total amounts of air pollutants involved. The present survey covers the period 2002–2019 and only civil aircrafts flights have been considered. In particular, the concentrations mono-nitrogen oxides (NOX), carbon monoxide (CO), carbon dioxide (CO₂), unburnt hydrocarbons (HC) and total Particulate Matter (PM) consisting of volatile organic PM, volatile sulphuric PM and non-volatile PM have been studied. According to the results obtained more than 6500 kt of CO₂, almost 28 kt of NOX, about 18 kt of CO, almost 1.5 kt of HC and 0.3 kt of PMₜₒₜₐₗ have been released into the atmosphere during the total operating time of the airport. Actions related to the conduct of new measurements of air pollutants are aimed which point to the reduction of their impacts in the coming years.

This study presents a method for “downscaling” aggregated global emissions of CO, NOₓ, and PM₂.₅ based on georeferenced information (spatial proxies). We distribute ECLIPSE-CLE emissions for Quito, Ecuador, in 2015 and 2017. The study area is a grid of 0.5 × 0.5 km² cells over a 110 × 110 km² area. The emission sectors (proxies in parenthesis) are agricultural (land-use maps), domestic (land-use and population density), energy, industry, and waste disposal (point source location from local inventory), and transport (population, vehicle traffic, and road density). Emission distribution quality is satisfactorily evaluated (graphically and statistically) by implementing them in the UBM model and comparing modeled concentrations with observations. This study also explores an alternative proxy set-up for main road emissions based on road density, which, for some modeling sites, results in a better agreement with the observations. Finally, this methodology is applied for comparing air pollution due to two urban growth types for Quito in 2040: sprawl and densification. Both scenarios lead to lower concentrations than in 2017, except for O₃. Although the two scenarios attain similar concentrations, urban sprawl presents, in general, noticeably higher values for NOₓ and NO₂.

Emission characteristics of biogenic volatile organic compounds (BVOCs) (such as isoprene and monoterpenes) emitted from major species of street trees and urban forests by variations in temperature and photosynthetically active radiation (PAR) were investigated. The isoprene and monoterpene emission rates from Prunus sargentii, Ginkgo biloba, Zelkova serrata and Taxus cuspidata were meager. In contrast, the isoprene and monoterpene emission rates from Metasequoia glyptostroboides were very high. In particular, the emission of α-pinene from Metasequoia glyptostroboides was over 10,000 times higher than that from Ginkgo biloba. The patterns of isoprene emissions from the four tree species except for Metasequoia glyptostroboides concerning temperature and PAR were difficult to determine because the emission rate is very low. However, monoterpene emissions from all five tree species were clearly affected by temperature and PAR. These results showed that the characteristics of isoprene and monoterpene emissions differed depending on the tree species. Regarding monoterpene composition, α-pinene (81.3%) accounts for the majority of total monoterpenes from Metasequoia glyptostroboides. This could be a critical consideration when planting trees in an urban forest because BVOC emissions (e.g., α-pinene) have been well known to affect ground-level ozone formation rate via photochemical reaction with NOX. Since Metasequoia glyptostroboides showed relatively high BVOC emissions, the use of this type of tree in an urban forest with relatively high nitrogen oxide emissions should be carefully considered.

Understanding and quantifying the influence of volatile organic compounds (VOCs) on ozone and secondary organic aerosol formation is essential for better prediction/estimation of these products. A total of 9 VOCs along with surface ozone were measured during the year 2019 at Pune (India) location. The ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) estimations are compared for 2 methods-using measured VOC concentrations and using their photochemical initial concentrations (PIC). The OFP and SOAFP estimated based on the measured VOC concentrations provide an incomplete understanding of these 2 formation processes. This is mainly because measured VOCs don't account for the photochemical losses that compounds undergo from the source to the receptor. The PIC values of VOCs have been estimated in this study to highlight the importance of considering the photochemical losses. For example, the PIC value of highly reactive compound, isoprene, was found to be 152% higher (1.48 ppbv) than its measured value (0.59 ppbv). The resultant total OFP estimate based on PIC values of all the VOCs was found to be 53.30 ± 35.02 ppbv as compared to 45.99 ± 29.35 ppbv obtained from measured VOCs. Based on k-means clustering analysis, it was found that the highest ozone formation was favored under transition regime chemistry when PIC values were considered. The average total SOAFP based on PIC values was found to be 1.32 ± 1.40 ppbv, while it was 1.17 ± 1.18 ppbv for measured VOCs. The aromatics contributed to over 90% of total SOAFP estimated for the region.

This study explored the interspecies and seasonal variation of polycyclic aromatic hydrocarbons (PAHs) in the extracted lipids of the leaves of seven local plants in an urban environment of Kolkata (22°33′N and 88°20′E), India. Based on the degree of toxicity and carcinogenicity (expressed in terms of their Benzo(a)pyrene equivalent (BaPeq) concentrations) the overall foliar-PAH accumulation during the study period (September 2018‒;August 2019) in the various plants showed the following order: Nerium oleander (80.96 ± 30.08 ng.gdw−1) > Mangifera indica (74.15 ± 20.34 ng.gdw−1) > Lantana aculeata (60.13 ± 21.71 ng.gdw−1) > Thevetia peruviana (40.97 ± 12.45 ng.gdw−1) > Ixora coccinea (38.11 ± 9.5 ng.gdw−1) > Murraya paniculata (37.1 ± 7.35 ng.gdw−1) > Polyalthia longifolia (25.72 ± 5.71 ng.gdw−1). The PAHs like phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo (b+k)fluoranthene, benzo(a)pyrene, benzo [ghi]perylene and indeno [1,2,3-cd]pyrene were predominant during the study period over the PAHs like naphthalene, acynaphthylene, acenaphthene, fluorine and dibenz [a,h]anthracene in the extracted lipids. The temperature-dependent partitioning of the PAHs onto leaf-surface and photo-degradation could have affected the availability of the PAHs. The foliar PAH accumulation varied seasonally as winter (December–February) > postmonsoon (September–November) > premonsoon (March–May) > monsoon (June–August). The leaf epicuticular wax determined the PAH uptake and storage, which in turn was affected by the temperature and solar radiation. In consistence with the idea of “nature-based solutions” for deteriorated air quality remediation in an urban environment, this study could be a promising initiative to build up cost-effective biological filters to combat the airborne pollutants and improve urban air quality.

Aerosols have severe effects on climate, human health and ecosystems. The impact of aerosols on climate, ecosystems and human health can be better understood if the variability of optical properties of aerosols is accurately known. In this paper, we have used Moderate Resolution Imaging Spectroradiometer (MODIS) datasets of aerosol optical depth (AOD) at 550 nm, Angstrom exponent (440/870) (AE) and enhanced vegetation index (EVI) over Pakistan. We have also analyzed the relationship between meteorological variables (e.g., temperature, relative humidity (RH) and wind speed (WS)) and aerosol optical properties to acquire a deep knowledge of aerosol variability. The coefficients of determination (R²) between Aqua-AOD and AERONET-AOD are found to be 0.6724 over Lahore and 0.7678 over Karachi. Aqua-AOD has also been validated with AOD data from Terra, MISR and SeaWiFS. High AOD (0.8–1) and low AE (0.4–0.8) have been observed over south and southwestern Pakistan indicating the presence of dust aerosols. In northeastern Pakistan, EVI is negatively correlated with AOD. The northeastern Pakistan is characterized by high values of AOD (~1) during all seasons. AOD showed a significant interannual variation with the lowest values (0.22) in January and the highest (0.58) in July. AE is observed to be lower in spring and summer than in winter and autumn seasons in south and south-western Pakistan. A positive R (≥0.6) is observed between AOD and temperature over the southwestern Pakistan while a negative R (−0.4 ≤) is observed between AOD and RH over the southwestern Pakistan.

Based on the ground-level observed NO₂ concentration, satellite-observed NO₂ column concentration from the Ozone Monitoring Instrument (OMI) and meteorological parameters, we comprehensively consider the seasonal and regional differences in the relationship between NO₂ column concentration and measured NO₂ concentration and establish a two-stage combined ground NO₂ concentration estimation (TSCE-NO₂) model using a support vector machine for regression (SVR) and a genetic algorithm optimized back propagation neural network (GABP). On this basis, the spatial-temporal variation in the modelled ground-level NO₂ concentration over China during the period of 2005–2019 was analysed. The results show that the TSCE-NO₂ model proposed in this study provides a reliable estimation of the modelled ground-level NO₂ concentration over China, effectively filling the spatial and temporal gaps in China's air quality ground monitoring network (the model's correlation coefficient, R, is 0.92, the mean absolute error, MAE, is 3.62 μg/m³, the mean square percentage error, MSPE, is 0.72%, and the root-mean-square error, RMSE, is 5.93 μg/m³). The analysis results of the spatial and temporal variation indicate that (1) the perennial ground-level NO₂ concentration over China is high in the eastern area and low in the western area, and the high values are mainly distributed along the northern coast, the eastern coast, the middle reaches of the Yangtze River, the middle reaches of the Yellow River, the Pearl River Delta and the Sichuan Basin. (2) The modelled ground-level NO₂ concentrations over China are highest in winter, followed by those in autumn and spring, and they are lowest in summer. Before 2011, the ground-level NO₂ concentration over China increased at a rate of 0.348 ± 0.132 μg/(m³∙a) but decreased at a rate of 0.312 ± 0.188 μg/(m³∙a) after 2011. (3) From 2011 to 2019, measures such as energy savings and emission reductions alleviated NO₂ pollution on the premise of ensuring sustained China's GDP growth.