Microplastics (MPs) and microfibers (MFs) in stormwater have been poorly investigated. Data on their intra and inter rain events variability over time are still sparse. For the first time, the variability of microlitter concentrations in stormwater has been studied. MF and MP concentrations were investigated in stormwater runoff at the outlet of the suburban catchment at Sucy-en-Brie (a suburb of Paris, France), during four rain events. Median MF and MP concentrations were 1.9 and 29 items/L, with an interquartile range of 2.3 and 36 items/L, respectively (N = 18). A different pattern was observed between MFs and MPs. While no relationship or trends were observed for MFs, the highest MP concentrations were observed before the flow rate peak of the rain events. This could indicate a difference in the behaviour between MFs and MPs. We estimated the median MP mass concentration to be 56 μg/L with an interquartile range of 194 μg/L, whereas the mass concentration of macroplastics was estimated to be 31 μg/L with an interquartile range of 22 μg/L at the same sampling site, in a previous study. For this sampling site, MPs and macroplastics have the same order of magnitude. This study may have strong implications on microplastic assessment in urban waters.

Heavy metals in atmospheric dust can directly pollute the soil, water and sediment, causing serious harm to human health. In this study, the temporal and spatial distribution characteristics of heavy metals in atmospheric deposition in western Taihu Lake were studied. We established 10 sampling sites to collect atmospheric deposition for two years in different seasons. The atmospheric deposition flux follows the order urban area (95.6 g m⁻²·a⁻¹) > suburban area (80.2 g m⁻²·a⁻¹) > forestland (56.8 g m⁻²·a⁻¹). The concentrations of heavy metals in atmospheric deposition show trends of high values in the winter and low values in the summer and are significantly negatively correlated with distance from the city. The pollution level of Igₑₒ-Cd is 6, which is very high, and that of E-Cd is 219, which means high risk. Heavy metals in atmospheric deposition are mainly taken up via hand-mouth intake, and the harm to children is significantly higher than the harm to adults. The highest health risk assessment values for the four analyzed heavy metals in atmospheric deposition are located near the city and in suburbs (within 5 km of the city center), that is, in areas where human activities are concentrated. The health risk assessment values in areas outside the suburbs are low; these areas are less affected by human activities. The health risk assessment values of heavy metals in the winter and spring are higher than those in the summer and autumn. The Pb isotope ratios show that the main sources of heavy metals in atmospheric deposition and local soil are human activities, such as industry and coal combustion, with less input from natural sources. Heavy metals in atmospheric deposition in the western part of Taihu Lake not only directly threaten local human health but also enter Taihu Lake, posing a serious threat to the Taihu Lake ecosystem.

Urbanization is conducive to promoting social development and improving living standards. However, the changing land use attributed to urbanization has placed both the environment and humans at risk. Based on the long-term monitoring and the land use change during 2010–2017, we investigated the exposure of fluoride (F) and arsenic (As) in groundwater. We analyzed the temporal and spatial variation of F and As from different land use changes. The study assessed health risk for children by calculating carcinogenic risk and non-carcinogenic risk. Furthermore, we mapped the distribution pattern of F and As using GIS. For the 768 water samples collected from 2010 to 2017, F concentrations ranged between 0.10 and 5.70 mg L⁻¹ (M = 0.68 ± 0.02 mg L⁻¹), As concentrations ranged between 0.50 and 71.50 μg L⁻¹ (M = 4.28 ± 0.28 μg L⁻¹). A concerning result showed that 6.77% of F concentrations larger than 1.5 mg L⁻¹ and 11.46% of As concentrations larger than 10 μg L⁻¹ based on the recommendation by WHO, respectively. Results proved that land use change caused by human activity increased groundwater pollution and placed human health at risk. High F and As risk were found in southern Taiyuan City. In particular, the groundwater of industrial land suffered from more severe pollution, especially at the frontier of urban and suburban areas in the southern part of Taiyuan City. Land use change attributed to industrial land resulted in major increases in the F and As concentrations in groundwater across 2010–2017. Both carcinogenic risk and non-carcinogenic risk in 2016–2017 were higher than that in 2010–2015. Rational land use planning, strict groundwater protection policies and the regular monitoring of pollution levels are necessary in order to prevent the adverse health of residents.

The atmospheric concentrations of 14 organophosphate esters (OPEs) were monitored by passive air sampling at 33 sites to determine their spatial distributions, and seasonal variations (summer and winter) in Tianjin, North China. The total concentrations of the OPEs (∑₉OPEs) in the summer ranged from 0.08 to 1113 ng/sample with a median of 98.4 ng/sample, which was non-statistically different from the concentrations obtained in the winter (which ranged from 1.93 to 548 ng/sample with a median of 46.2 ng/sample). Among the observed OPEs, the concentrations of TnBP and TCiPP were statistically higher in the summer compared with the winter (p < 0.05). For grouped OPEs, only a significantly higher level of chlorinated OPEs was found in summer than that in winter. In the winter, spatial differences were found to be significantly different between the concentrations of TnBP, TiBP, TCEP, and TEHP in the suburban and rural areas (p < 0.05). Considering the possible point-sources, in the summer, the concentrations of TDCPP, TCiPP, DPEHP, TEHP, and the total concentration of TCPs (denoted as ∑₃TCP, comprised of the concentrations of TCP, TmCP, and ToCP) in an electronic-waste (e-waste) dismantling area were higher than those obtained at the other sampling sites. ∑₉OPEs at the e-waste site and another site located near a manufacturing plant of organophosphate flame retardants (OFRs) were both higher than the median concentrations obtained at the other sampling sites, and TCiPP was the most abundant pollutant. In the winter, the concentrations of ∑₉OPEs at the e-waste site were still higher than their median concentrations at the other sites. Because OPEs are used in aircraft lubricating oils and hydraulic fluids, an airport was thought to be another important source of TiBP and TPhP in the present study. Therefore, the e-waste site, airport, and OFR manufacturing plant may be the major sources of OPEs in the environment.

Coal-Gas replacement project has been implemented to decrease haze pollution in China in recent years. Airborne arsenic (As) mostly originates from coal burning processes. It is noteworthy to compare the distribution of arsenic fraction in PM₂.₅ before and after coal-gas replacement. Eighty PM₂.₅ samples were collected in Baoding in December 2016 (coal dominated year) and December 2017 (gas dominated year) at different functional areas including residential area (RA), industrial area (IA), suburb (SB), roadside (ST) and Botanical Garden Park (BG). The fraction, bioavailability and health risk of As in the PM₂.₅ samples were investigated and compared between these two years. Arsenic was mainly distributed in the non-specifically sorbed fraction (F1) and the residual fraction (F5). However, the proportion of F1 to the total As in 2017 was higher than that in 2016, while the proportion of As in the amorphous and poorly-crystalline hydrous oxides of Fe and Al fraction (F3) in 2017 was lower. The distributions of fraction and bioavailability showed temporal and spatial characteristics. The total concentration and bioavailability of As in SB and IA were significantly higher than those in RA, ST and BG. The BF (Bioavailability Factor) values of As ranged from 0.30 to 0.61. Health risk assessment indicated that the hazard quotient (HQ) and carcinogenic risk (CR) of As in PM₂.₅ significantly decreased after coal-gas replacement.

In the study, personal PM₂.₅ exposures and their source contributions were characterized for 159 subjects living in the Beijing Metropolitan area. The exposures and sources were examined as functions of residential location, season, vocation, cigarette smoking, and time spent outdoors. Sampling was performed for two categories of volunteers, guards and students, that lived in urban and suburban areas of Beijing. Samples were collected using portable PM₂.₅ monitors during summer and winter. Exposure measurements were supplemented with a questionnaire that tracked personal activity and time spent in microenvironments that may have impacted exposures. Simultaneously, ambient PM₂.₅ data were obtained from national network stations located at the Gucheng and Huairouzhen sites. These data were used as a comparison against the personal PM₂.₅ exposures and produced poor correlations between personal and ambient PM₂.₅. These results demonstrate that individual behavior strongly affects personal PM₂.₅ exposure. Six primary sources of personal PM₂.₅ exposure were determined using a positive matrix factorization (PMF) source apportionment model. These sources included Roadway Transport Source, Soil/Dust Source, Industrial/Combustion Source, Secondary Inorganic Source, Cd Source, and Household Heating Source. Averaged across all subjects and seasons, the highest source contribution was Secondary Inorganic Source (24.8% ± 32.6%, AVG ± STD), whereas the largest primary ambient source was determined to be Roadway Transport (20.9% ± 13.6%). Subjects were classified according to the questionnaire and were used to help understand the relationship between personal activity and source contribution to PM₂.₅ exposure. In general, primary ambient sources showed only significant spatial and seasonal differences, while secondary sources differed significantly between populations with different personal behavior. In particular, Cd source was found to be related to smoking exposure and was the most unpredictable source, with significant differences between populations of different sites, vocations, smoking exposures, and outdoor time.

Twenty-six polycyclic aromatic hydrocarbons (PAHs) and four synthetic musk compounds (SMCs) accumulated by Masson pine needles from different areas of Shanghai were investigated in the present study. Concentrations of Σ26PAHs (sum of 26 PAHs) ranged from 234 × 10−3 to 5370 × 10−3 mg kg−1. Levels of Σ26PAHs in different sampling areas followed the order: urban areas (Puxi and Pudong) > suburbs > Chongming. Total concentrations of 16 USEPA priority PAHs ranged from 225 × 10−3 to 5180 × 10−3 mg kg−1, ranking at a relatively high level compared to other regions around the world. Factor analysis and multi-linear regression model has identified six sources of PAHs with relative contributions of 15.1% for F1 (vehicle emissions), 47.8% for F2 (natural gas and biomass combustion), 7.8% for F3 (oil), 10.6% for F4 (coal combustion), 15.7% for F5 (“anthracene” source) and 3.0% for F6 (coke tar). Total concentrations of 4 SMCs varied between 0.071 × 10−3 and 2.72 × 10−3 mg kg−1 in pine needles from Shanghai. SMCs with the highest detected frequency were Galaxolide and musk xylene, followed by musk ketone and Tonalide. The highest level of SMCs was found near industrial park and daily chemical plant. The results obtained from this study may have important reference value for local government in the control of atmospheric organic pollution.

The fast economic development of southwest China has resulted in significant increases in the concentrations of reactive nitrogen (Nr) in the atmosphere. In this study, an urban (Chengdu, CD), suburban (Shifang, SF) and agriculture (Yanting, YT) – dominated location in the Sichuan Province, southwest China, were selected to investigate the atmospheric composition of Nr, their concentrations and deposition rates. We measured Nr concentrations in precipitation (NH₄⁺, NO₃⁻ and organic N (DON)), the gas phase (NH₃ and NO₂), and the aerosol particles (PM₂.₅), and calculated their fluxes over a two year period (2014–2016). Total annual N deposition rates were 49.2, 44.7 and 19.8 kg N ha⁻¹ yr⁻¹ at CD, SF and YT, respectively. Ammonia concentrations were larger at the urban and suburban sites than the agricultural site (12.2, 14.9, and 4.9 μg N m⁻³ at CD, SF and YT, respectively). This is consistent with the multitude of larger sources of NH₃, including city garbage, livestock and traffic, in the urban and suburban areas. Monthly NO₂ concentrations were lower in warmer compared to the colder months, but seasonal differences were insignificant. Daily PM₂.₅ concentrations ranged from 7.7 to 236.0, 5.0–210.4 and 4.2–128.4 μg m⁻³ at CD, SF and YT, respectively, and showed significant correlations with fine particulate NH₄⁺ and NO₃⁻ concentrations. Ratios of reduced to oxidized N were in the range of 1.6–2.7. This implies that the control of reduced Nr especially in urban environments is needed to improve local air quality.

Investigating the nature of PM₁₀ is crucial to differentiate sources and their relative contributions. In this study we compared the levels, and the chemical and mineralogical properties of PM₁₀ particles sampled in different seasons at monitoring stations representative of urban background, urban traffic and suburban traffic areas of Naples city. The aims were to relate the PM₁₀ load and characteristics to the location of the monitoring stations, to investigate the different sources contributing to PM₁₀ and to highlight PM₁₀ seasonal variability. Bulk analyses of chemical species in the PM₁₀ fraction included total carbon and nitrogen, δ¹³C and other 20 elements. Both natural and anthropogenic sources were found to contribute to the exceedances of the EU PM₁₀ limit values. The natural contribution was mainly related to marine aerosols and soil dust, as highlighted by X-ray diffractometry and SEM-EDS microscopy. The percentage of total carbon suggested a higher contribution of biogenic components to PM₁₀ in spring. However, this result was not supported by the δ¹³C values which were seasonally homogeneous and not sufficient to extract single emission sources. No significant differences, in terms of PM₁₀ load and chemistry, were observed between monitoring stations with different locations, suggesting a homogeneous distribution of PM₁₀ on the studied area in all seasons. The anthropogenic contribution to PM₁₀ seemed to dominate in all sites and seasons with vehicular traffic acting as a main source mostly by generation of non-exhaust emissions Our findings reinforce the need to focus more on the analysis of PM₁₀ in terms of quality than of load, to reconsider the criteria for the classification and the spatial distribution of the monitoring stations within urban and suburban areas, with a special attention to the background location, and to emphasize all the policies promoting sustainable mobility and reduction of both exhaust and not-exhaust traffic-related emissions.

Previous ecological risk assessments were mainly concentration-oriented rather than source-oriented. Moreover, land use is usually related to source emissions but was rarely used to improve the source apportionment accuracy. In this study, the land-use effects of heavy metals (HMs) in surface (0–20 cm) and subsurface (20–40 cm) soils were first explored using ANOVA in a suburb of Changzhou City, China; next, based on robust absolute principal component scores-robust geographically weighted regression (RAPCS/RGWR), this study proposed RAPCS/RGWR with land-use type (RAPCS/RGWR-LUT) and compared its source apportionment accuracy with those of basic RAPCS/RGWR and commonly-used absolute principal component scores/multiple linear regression (APCS/MLR); then, the source-oriented ecological risks were apportioned based on RAPCS/RGWR-LUT and Hakanson potential ecological risk index method; finally, this study proposed robust residual kriging with land-use type (RRK) for spatially predicting the source-oriented ecological risks, and compared its spatial prediction accuracy with those of robust ordinary kriging (ROK) and traditionally-used ordinary kriging (OK). Results showed that: (i) by incorporating land-use effects, RAPCS/RGWR-LUT obtained higher source apportionment accuracy than RAPCS/RGWR and APCS/MLR; (ii) the two most important external input sources of the ecological risks were 'atmospheric deposition' (PERIₛᵤᵣfₐcₑ = 47.11 and PERIₛᵤbₛᵤᵣfₐcₑ = 35.27) and 'agronomic measure' (PERIₛᵤᵣfₐcₑ = 28.93 and PERIₛᵤbₛᵤᵣfₐcₑ = 20.37); (iii) the biggest ecological risk factor was soil Cd (ERₛᵤᵣfₐcₑ = 57.14 and ERₛᵤbₛᵤᵣfₐcₑ = 47.62), which was mainly contributed by 'atmospheric deposition' (ERₛᵤᵣfₐcₑ=33.14 and ERₛᵤbₛᵤᵣfₐcₑ=25.71); (iv) RRK obtained higher spatial prediction accuracy than ROK and OK; (v) the high-risk areas derived from 'atmospheric deposition' were mainly located in the southwest of the study area, and the high-risk areas derived from 'agronomic measure' were scattered in the agricultural land in the north and south of the study area. The above information provided effective spatial decision support for reducing the source-oriented input of the ecological risks of soil HMs in a large-scale area.