Air pollutants influence the morphological, physiological, and biochemical status of plants, and their impacts vary substantially among different species and cultivars. Current review synthesises published literature on the assessment of air pollution impacts on vegetation, with a specific focus on chronicling and summarizing scientific methods that quantify those impacts. Investigations carried out globally on pollutant-plant exposure-response, and articles that describe impact of air pollutants on plants and pollutant abatement using green infrastructure (GI) were systematically reviewed. 273 articles reviewed indicated that a substantial number of past explorations were on a small spectrum of certain species, mainly wheat, rice, soybean and maize; and fewer on non-crop plant species, which cover most of the urban areas and are part of GI. Furthermore, in lower middle-income countries which face significant pollution loads, even studies on crop species are limited. Most studies either use Air Pollution Tolerance Index, which is not pollutant dependent or concentrate on either Ozone or Particulate Matter (PM) and rarely investigate the impact of multiple pollutants in the atmosphere. Also, very few studies differentiate the effect of PM on plants based on its composition. Subsequently, the best possible experimental set ups and wide array of plant health parameters for determining and understanding the effects of different air pollutants on a variety of plant species has been emphasized. While this review compiled literature-based commendations for academic federations wanting to study and quantify air pollutant impacts on vegetation, numerous pertinent vital topics for future research were identified.

Ambient concentrations and sources of non-Methane Hydrocarbons (NMHCs) with 6–9 carbon atoms were investigated at an industrialized coastal location within the Port of Piraeus in Greece. Measurements were performed for a yearlong period during 2019 by means of an automated gas chromatograph with flame ionization detector (GC-FID). N-Hexane registered the highest annual mean concentration, followed by toluene and benzene, whereas all compounds presented important day to day variability, with an enhancement in summer. The seasonal diurnal cycles were characterized by strong morning peaks, especially in summer. The night-time maxima were less pronounced during the warm period, by almost 50% relative to the morning ones. On the contrary, during winter night-time, the combined impact of emissions and the shallow boundary layer was reflected on the night-time peaks. The area seems to be affected mainly by local land emission sources, whereas temperature possibly triggers evaporation processes, as indicated by comparisons with nearby traffic and urban background sites. The enhanced NMHCs concentration, in spite of increased ventilation coefficients during the summer, indicated again the impact of local emission sources. This was also highlighted by means of Positive Matrix Factorization (PMF) modeling. Three PMF factors were identified, quantified and supported by supplementary seasonal runs during short-term campaigns. Fugitive emissions were recognized as the main source, contributing more than 70% of total NMHCs year-round, while the input of emissions associated with traffic and diesel combustion was almost equal (13% and 15%, respectively).

The present work compared both the bioaccumulation of trace elements and the values of ecophysiological parameters measured in thalli of the lichen Pseudevernia furfuracea (L.) Zopf in two monitoring campaigns performed before and after improvement measures put in place by a 15 MW biomass power plant (BPP): the activation of a concentrated solar thermodynamic plant and the increasing percentage of exhausted olive pomace used as fuel. The cases of no enrichment and moderate enrichment change from 49 and 17% in 2013 to 68 and 4.2% in 2019, respectively. Several metals in 2019, show a Delta (difference between exposed and not exposed lichen thalli concentration) that is significantly lower than in 2013. The spatial pattern of contamination is comparable between the two years. However, the BPP affects the spatial variation of Ti, Al, V and Co in both 2019 and 2013, but only in the latter year also that of Cu, Cr and As which, in some monitoring sites, developed extremely high levels of enrichment. Traffic, whose rate increased over time, constantly influences the bioaccumulation of Cu, Sb and Mo. In 2019, the lichen oxidative stress is significantly reduced as well as the number of correlations between malondialdehyde levels and those of trace elements. Pigment values never differ (p > 0.05) from pre-exposure levels. Our results suggest that the development of hybrid plants, as well as a better fuel selection can reduce the environmental impact due to the combustion of biomass contributing to make this type of energy source more sustainable.

Countries in Northeast Asia have been regulating PM₂.₅ sources and studying their local and transboundary origins since PM₂.₅ causes severe impacts on public health and economic losses. However, the separation of local and transboundary impacts is not fully realized because it is impossible to change air pollutant emissions from multiple countries experimentally. Exceptionally, the early stage of the COVID-19 outbreak (January–March 2020) provided a cross-country experiment to separate each impact of PM₂.₅ sources identified in Seoul, a downwind area of China. We evaluated the contributions of PM₂.₅ sources compared to 2019 using dispersion normalized positive matrix factorization (DN-PMF) during three meteorological episodes. Episodes 1 and 2 revealed transboundary impacts and were related to reduced anthropogenic emissions and accumulated primary pollutants in Northeast China. Anthropogenic emissions, except for the residential sector, decreased, but primary air pollutants accumulated by residential coal combustion enhanced secondary aerosol formation. Thus, the contributions of sulfate and secondary nitrate increased in Seoul during episode 1 but then decreased maximally with other primary sources (biomass burning, district heating and incineration, industrial sources, and oil combustion) during episode 2 under meteorological conditions favorable to long-range transport. Local impact was demonstrated by atmospheric stagnation during episode 3. Meteorological condition unfavorable to local dispersion elevated the contributions of mobile and coal combustion and further contributed to PM₂.₅ high concentration events (HCE). Our study separates the local and transboundary impacts and highlights that cooperations in Northeast Asia on secondary aerosol formation and management of local sources are necessary.

Sleep is a crucial aspect of the human daily life since it allows us to recover from physical and psychological fatigue and its lack can bring several consequences to human health. People spend around one third of their life sleeping but, despite that, their exposure to pollutants during sleep is often neglected. Specifically, students typically change their habits after entering university, due to the freedom that they are allowed at this stage of their lives. These habits often include their sleep patterns, which not only affects their health, but their academic performance as well. This study aimed to assess the indoor air quality (IAQ) that university students are exposed to in their sleeping environment and how it affects their sleep quality. Firstly, an online survey, based in standardized questionnaires, was conducted to a sample of 1040 individuals to characterize sleep habits and, ultimately, to provide an overview of the sleep quality of the Portuguese population. Students were one of the population groups that showed worse results: only 31% had good sleep quality and only 62% showed good sleep health. Afterwards, a study to assess sleep quality (by actigraphy and standardized questionnaires) and IAQ (by a monitoring unit based in low-cost sensors) during the sleeping period of two consecutive nights of 13 students in Lisbon university dorms was conducted. Mean levels of CO₂ and VOCs above the established legislation were found during sleep, indicating that ventilation conditions were not sufficient to keep an acceptable IAQ. Temperature was also out of the acceptable comfort range during 44% of the sleeping time. The perceived sleep quality of students was found to be negatively associated with the number of awakenings and the mean levels of carbon dioxide and relative humidity during the sleeping period. These results confirm previous findings where some IAQ parameters may influence the sleep quality of the individuals, highlighting the importance to focus on the IAQ of sleeping environments as a strategy to improve sleep quality of individuals.

In Belgium, 16 shredding facilities manage annually tens of thousands tons of wastes from different origins (end-of-life vehicles, electronic waste, electrical transformers, …). These materials contain hazardous persistent organic pollutants such as polychlorinated dibenzo-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The shredding process promotes the production and the emission of dust contaminated by these compounds. The objective of this study is to measure the concentrations of PCDD/Fs, PCBs and PBDEs in fallout dust collected in the vicinity of 3 shredding plants located in Wallonia (French speaking part of Belgium). Samples were collected by using Owen gauges and pollutant levels were measured by GC-MS. The median deposition levels measured for ∑PCDD/Fs, ∑dioxin-like PCBs, 5 × ∑6 DIN PCBs and PBDE 209 were 1.9 pg TEQ/m².day, 4.4 pg TEQ/m².day, 246.5 ng/m².day and 253.8 ng/m².day, respectively. These levels represent high concentrations compared to those observed in most of the remote, rural and urban areas studied around the world and were similar to those measured in other heavily industrialized districts. Consequently, the health effects of this high exposure to pollutants among workers and residents in the vicinity of these shredding facilities are of concern.

A source apportionment study was carried out at four sites in Emilia-Romagna region, southern Po Valley, one of the most critical regions in Europe in terms of atmospheric pollution. PM₂.₅ daily samples were collected during 4 years from April 2013 to October 2017 at one rural site (San Pietro Capofiume) and three urban background locations in the cities of Bologna, Rimini, Parma which show different features and are located in the central, coastal and inner part of the investigated region. Samples were analyzed to achieve a complete chemical characterization (carbon fractions, ions, and elements). A source apportionment analysis by Positive Matrix Factorization (PMF) was performed and 6 PM₂.₅ factors were identified at all sites but the rural one (where 5 out of 6 of them were detected); the factors were associated to traffic with dust resuspension, biomass burning, oil combustion/ship emission, mix anthropogenic (not found at the rural site), ammonium nitrate and ammonium sulfate with organics. Chemical profiles of factors were very similar among all the 4 sites, indicating that main pollution sources are basically the same at the 4 sites, while some differences emerged with regard to source contributions. Factors related to secondary components seem to explain almost 50% or even more of PM₂.₅ mass concentration in all seasons. Traffic and biomass burning are the most relevant contributors to PM₂.₅ in terms of primary components. A not negligible contribution of biomass burning results in Rimini during the summer, suggesting other possible sources of wood combustion, such as cooking or open burning of agricultural pruning bonfires. Agriculture is not singled out as a PMF factor, but a rough estimate based on ammonium concentrations and ammonia data from emission inventory indicates a contribution from this source of about 10% of PM₂.₅ mass, thus resulting the single productive activity with the highest impact on PM₂.₅ at the investigated sites. Back trajectory analysis points out the relevant extra-regional contributions of two factors; indeed, oil combustion/ship emission is related to long-range transport of air masses overpassing the Mediterranean sea and secondary sulfate from Eastern Europe countries occasionally impacts on the Po Valley.