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Micro-nano plastics (MNPs; size <5 mm), ubiquitous and emerging pollutants, accumulated in the natural environment through various sources, and are likely to interact with nutrients, thereby influencing their biogeochemical cycle. Increasing scientific evidences reveal that MNPs can affect nitrogen (N) cycle processes by affecting biotopes and organisms in the environmental matrix and MNPs biofilms, thus plays a crucial role in nitrous oxide (N 2 O) and ammonia (NH 3) emission. Yet, the mechanism and key processes behind this have not been systematically reviewed in natural environments. In this review, we systematically summarize the effects of MNPs on N transformation in terrestrial, aquatic, and atmospheric ecosystems. The effects of MNPs properties on N content, composition, and function of the microbial community, enzyme activity, gene abundance and plant N uptake in different environmental conditions has been briefly discussed. The review highlights the significant potential of MNPs to alter the properties of the environmental matrix, microbes and plant or animal physiology, resulting in changes in N uptake and metabolic efficiency in plants, thereby inhibiting organic nitrogen (ON) formation and reducing N bioavailability, or altering NH 3 emissions from animal sources. The faster the decomposition of plastics, the more intense the perturbation of MNPs to organisms in the natural ecosystem. Findings of this provide a more comprehensive analysis and research directions to the environmentalists, policy makers, water resources planners & managers, biologists, and biotechnologists to do integrate approaches to reach the practical engineering solutions which will further diminish the long-term ecological and climatic risks. [Display omitted] • Micro-nano plastics (MNPs) impact N cycle in ecosystems. • Properties of MNPs are the key factors of environmental roles. • Microorganisms in environmental matrix and MNPs biofilms differ significantly. • MNPs influence microbial structure, activities and evolution in environment. • Effects of MNPs on plants, animals, and microorganisms are interrelated. [ABSTRACT FROM AUTHOR]

As typical antibiotics, tetracycline (TC) and sulfadiazine (SDZ) enter the human body through the food chain. Therefore, it is necessary to understand their individual and combined toxicity. In this study, the effects of TC, SDZ, and their mixture on cell viability, cell membrane damage, liver cell damage, and oxidative damage were evaluated in in vitro assays with human liver cells Huh-7. The results showed cytotoxicity of TC, SDZ, and their mixture, which induced oxidative stress and caused membrane and cell damage. The effect of antibiotics on Huh-7 cells increased with increasing concentration, except for lactate dehydrogenase (LDH) activity that commonly showed a threshold concentration response and cell viability, which commonly showed a biphasic trend, suggesting the possibility of hormetic responses where proper doses are included. The toxicity of TC was commonly higher than that of SDZ when applied at the same concentration. These findings shed light on the individual and joint effects of these major antibiotics on liver cells, providing a scientific basis for the evaluation of antibiotic toxicity and associated risks. [Display omitted] • Tetracycline and sulfadiazine cause liver cytotoxicity increased with concentration. • Tetracycline was more toxic than sulfadiazine to liver. • Cell viability showed biphasic response while membrane damage was threshold. • Toxicity mechanism was through oxidative stress and liver cell and membrane damage. • Toxicity mechanisms differed between individual antibiotics and their mixture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Coal type affects particulate emission composition and cytotoxicity. • Water-soluble ions dominate PM 10 from honeycomb, anthracite, and industrial coals. • PM 10 from bituminous coal is dominated by carbonaceous components. • Heavy metals and water-soluble ions in PM 10 strongly correlated with cytotoxicity. • Limiting anthracite coal combustion is crucial in air quality for public health. Inhalable particles (PM 10 , particulate matters with an aerodynamic diameter < 10 μm) emitted from coal combustions is one of the most significant contributors to air pollution, endangering human health. The compositions of emissions and corresponding health risks of different types of coal sources are currently unclear. To address this, ten distinct types of coal were burnt, and original PM 10 samples were collected using dilution channel samplers. Subsequently, we performed a componential analysis on the collected samples and conducted in vitro cytotoxicity tests. Results showed that PM 10 from honeycomb, anthracite and industrial coals were dominated by water-soluble ions, while bituminous coal was dominated by carbonaceous components. Although heavy metal contents were lower than other investigated components in these PM 10 , they were still enriched in Fe, Pb and Zn. The NH 4 +, Cl- and SO 4 2- account for a large proportion of water-soluble ions. PM 10 induced obvious cytotoxicity to human lung cell A549, and the ability of anthracite coal to induce cellular TNF-α production was greater than that of honeycomb and bituminous coal. For IL-6, industrial coal elicited a stronger response than bituminous coal, followed by honeycomb and anthracite coal. Correlation analysis revealed that although heavy metals (Fe, Mn, Co, Ni, Cu) and water-soluble ions (K+, Ca2+, F-) accounted for less particle mass, they were strongly and significantly correlated with oxidative stress and inflammatory damage (r > 0.6, p < 0.05). Considering the actual coal consumption amount, our study identified restricting anthracite coal combustion should be a crucial focus for aerosol pollution control and public health protection policies. The results of the study not only increase the understanding of the chemical composition and cytotoxicity of PM 10 from the perspective of source emissions, but also provide targeted advice on the control of coal combustion, which is of great significance in environmental research, public health policy and air pollution control efforts. [ABSTRACT FROM AUTHOR]

Because heavy metals (HMs) occurring naturally in soils accumulate continuously due to human activities, identifying and apportioning their sources becomes a challenging task for pollution prevention in urban environments. Besides the enrichment factors (EFs) and principal component analysis (PCA) for source classification, the receptor model (Absolute Principal Component Scores-Multiple Linear Regression, APCS-MLR) and Pb isotopic mixing model were also developed to quantify the source contribution for typical HMs (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) in urban park soils of Xiamen, a representative megacity in southeast China. Furthermore, distribution patterns of their concentrations and sources in 13 soil profiles (top 20 cm) were investigated by different depths (0–5, 5–10, 10–20 cm). Currently the principal anthropogenic source for HMs in urban soil of China is atmospheric deposition from coal combustion rather than vehicle exhaust. Specifically for Pb source by isotopic model ( 206 Pb/ 207 Pb and 208 Pb/ 207 Pb), the average contributions were natural (49%) > coal combustion (45%) ≫ traffic emissions (6%). Although the urban surface soils are usually more contaminated owing to recent and current human sources, leaching effects and historic vehicle emissions can also make deep soil layer contaminated by HMs. [ABSTRACT FROM AUTHOR]

Abstract: Trace metals in soils may pose risks to both ecosystem and human health, especially in an urban environment. However, only a fraction of the metal content in soil is mobile and/or available for biota uptake and human ingestion. Various environmental availabilities of trace metals (Cu, Pb and Zn) in topsoil from highly urbanized areas of Hong Kong to plants, organisms, and humans, as well as the leaching potential to groundwater were evaluated in the present study. Forty selected soil samples were extracted with 0.11M acid acetic, 0.01M calcium chloride, 0.005M diethylenetriaminepentaacetic acid, and simplified physiologically based extraction tests (PBET) for the operationally defined mobilizable, effectively bioavailable, potentially bioavailable, and human bioaccessible metal fractions, respectively. The metals were generally in the order of Zn>Cu∼Pb for both mobility (24%, 7.6%, 6.7%) and effective bioavailability (2.8%, 0.9%, 0.6%), Pb (18%)>Cu (13%)>Zn (7.4%) for potential bioavailability, and Pb (59%)∼Cu (58%)>Zn (38%) for human bioaccessibility. Although the variations in the different available concentrations of metals could mostly be explained by total metal concentrations in soil, the regression model predictions were further improved by the incorporation of soil physicochemical properties (pH, OM, EC). The effectively bioavailable Zn and Pb were mostly related to soil pH. Anthropogenic Pb in urban soils tended to be environmentally available as indicated by Pb isotopic composition analysis. Combining various site-specific environmental availabilities might produce a more realistic estimation for the integrated ecological and human health risks of metal contamination in urban soils. [Copyright &y& Elsevier]

Abstract: Contaminants in urban soils can directly pose significant human health risks through oral ingestion, particle inhalation, and dermal contact, especially for children in public parks. Both non-carcinogenic and carcinogenic risks of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) were characterized in 40 surface soils (exposed lawns) from 14 urban parks in Xiamen, China. Results based on total metal concentrations may overestimate the actual risks in comparison with oral bioaccessibility assessment that were estimated by a simplified physiologically based extraction test (SBET). After considering the soil-specific bioaccessibility (Cd>Cu>Pb>Mn>Zn>Co~Ni>Cr), the non-cancer hazard of Pb to children via oral ingestion should be a consideration though its Hazard Index (HI) was below one. The overall cancer risks to adults still exceeded the target value 10−6, mainly contributed by Cr (93.8%) and Pb (6.19%) via dermal contact (68.3%) and oral ingestion (30.4%). To produce a more realistic estimation for human health risks of metal contamination in urban soils, a framework combining land use type and bioaccessibility is recommended and thereby should be applied for the derivation of risk-based, site-specific soil guidelines. [Copyright &y& Elsevier]

Abstract: The contamination of urban soils can affect the health of people living in urban areas, and the surrounding ecosystems. Urbanization in China has taken place at an unprecedented pace in the last three decades. This paper provides an overview of studies on the quality of urban soils in China with special reference to trace metal contamination. It summarizes the characteristics of accumulation, spatial and temporal distribution, and major sources of various toxic or potentially toxic trace metals in urban soils as reported in recent literature. Levels of pollution in urban soil and road dust were discussed using the concentrations, enrichment factors, pollution indexes, and chemical fractionation of trace metals in major cities of China, and compared with other countries. In future studies, more pollutants in urban environments need to be included in multi-compartmental environmental surveillance for potential risk assessments. In addition to routine urban soil surveys by a harmonized methodology, a comprehensive assessment of soil quality is needed for the control and management of many urban brownfield sites. Taking into consideration pathways of exposure and site characteristics, risk assessment frameworks for major pollutants in urban soils, which integrate land use type and environmental availability, may be developed in the future. [Copyright &y& Elsevier]

Urban soil Pb contamination is a great human health risk. Lead distribution and source in topsoils from 14 parks in Shanghai, China were investigated along an urban–rural gradient. Topsoils were contaminated averagely with 65 mg Pb kg−1, 2.5 times higher than local soil background concentrations. HCl-extracts contained more anthropogenic Pb signatures than total sample digests as revealed by the higher 207/206Pb and 208/206Pb ratios in extracts (0.8613 ± 0.0094 and 2.1085 ± 0.0121 versus total digests 0.8575 ± 0.0098 and 2.0959 ± 0.0116). This suggests a higher sensitivity of HCl-extraction than total digestion in identifying anthropogenic Pb sources. Coal combustion emission was identified as the major anthropogenic Pb source (averagely 47%) while leaded gasoline emission contributed 12% overall. Urbanization effects were observed by total Pb content and anthropogenic Pb contribution. This study suggests that to reduce Pb contamination, Shanghai might have to change its energy composition to clean energy. [Copyright &y& Elsevier]

The concentration and loading distribution of trace metals (Cu, Zn, Pb, Co, Ni, Cr, and Mn) and major elements (Al, Ca, Fe, and Mg) in different particle size fractions (2000–280, 280–100, 100–50, 50–10, 10–2, and <2μm) of surface soils from highly urbanized areas in Hong Kong were studied. The enrichment of Pb, Cu, and Zn in the urban soils was strongly influenced by anthropogenic activities, and Pb accumulated in fine particles was mainly derived from past vehicular emissions as shown by Pb isotopic signatures. Trace metals primarily accumulated in clay, fine silt, and very fine sand fractions, and might pose potential health risks via the inhalation of resuspended soil particles in the air (PM10 or PM2.5), and ingestion of adhered soils through the hand-to-mouth pathway. The mobility, bioavailability, and human bioaccessibility of Pb and Zn in bulk soils correlated significantly with metal concentrations in fine silt and/or very fine sand fractions. [Copyright &y& Elsevier]

The extent to which calcium, magnesium, sodium, potassium and hydrogen ions independently mitigate Cu rhizotoxicity to wheat (Triticum aestivum) in nutrient solutions was examined. Increasing activities of Ca2+ and Mg2+ but not Na+, K+ and H+ linearly increased the 2 d EC50 (as Cu2+ activity), supporting the concept that some cations can compete with Cu2+ for binding the active sites at the terrestrial organism–solution interface (i.e., the biotic ligand, BL). According to the biotic ligand model (BLM) concept, the conditional stability constants for the binding of Cu2+, Ca2+ and Mg2+ to the BL were derived from the toxicity data. They were 6.28, 2.43 and 3.34 for log K CuBL, log K CaBL and log K MgBL, respectively. It was calculated that on average 43.6% of BL sites need to be occupied by Cu2+ to induce 50% root growth inhibition. Using the estimated parameters, a BLM was successfully developed to predict Cu toxicity for wheat as a function of solution characteristics. [Copyright &y& Elsevier]

Abstract: To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode (ISE) and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid (IDA), ethylenediamine (EN), and glycine (Gly) were compared for calibrating the Cu-ISE curves in the range of free cupric ions (pCu2+) 7–13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu2+ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu2+ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu2+ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu2+ (with R 2 value of 0.76), while not important for the soluble Cu concentration. [Copyright &y& Elsevier]

PM 2.5 pollution is a widespread environmental and health problem, particularly in China. Besides leading to well-known diseases in the respiratory system, PM 2.5 can also alter immune function to induce or aggravate allergic diseases. To determine whether there are temporal and spatial differences in the allergic responses to PM 2.5 , monthly samples were collected from four regions (urban, industrial, suburban, and rural areas) through a whole year in Nanjing city, China. Inorganic chemical components (metals and water-soluble ions) of PM 2.5 were analyzed, and the rat basophil cells (RBL-2H3) exposed to PM 2.5 were assessed through quantitative measures of degranulation (β-hex and histamine) and pro-inflammation cytokine (IL-4 and TNF-α) expression. The highest levels of β-hex were measured in winter and spring PM 2.5 from urban and industrial areas, or autumn PM 2.5 from suburban and rural areas. With respect to histamine, autumn PM 2.5 samples were most potent irrespective of the location. Autumn and winter PM 2.5 induced higher levels of IL-4 than spring and summer samples. However, spring and autumn PM 2.5 caused higher levels of TNF-α. The concentrations of water-soluble ions (NH 4 +, K+ and Cl−), as well as heavy metals (Pb and Cr), were directly and statistically correlated to the inflammation observed in vitro. In general, the differences between regional and seasonal PM 2.5 in stimulating cell degranulation may depend on endotoxin and airborne allergen content of PM 2.5. The heavy metals and water-soluble ions in PM 2.5 were mostly anthropogenic, which increased the particles' mass-based cellular inflammatory potential, therefore, their health risks, e.g. from vehicular exhaust, coal, and biomass combustion, cannot be ignored. [Display omitted] • PM 2.5 could directly enhance β-hexosaminidase release by basophilic cells. • Degranulation of basophil cells exposed to PM 2.5 show regional and seasonal variations. • PM 2.5 shows the strong pro-inflammation effect on basophilic cells. • Airborne heavy metals and water-soluble ions correlate positively with cell inflammatory response. • PM 2.5 -induced cellular inflammation was driven by anthropogenic sources. [ABSTRACT FROM AUTHOR]

Accumulation and oral bioavailability of nickel (Ni) were rarely assessed for staple crops grown in high geogenic Ni soils. To assess exposure risk of geogenic Ni, soil, wheat, and rice samples were collected from a naturally high background Ni area and measured for Ni oral relative bioavailability (RBA, relative to NiSO 4) using a newly developed mouse urinary Ni excretion bioassay. Results showed that soils were enriched with Ni (80.5 ± 23.0 mg kg−1, n = 58), while high Ni contents were observed in rice (2.66 ± 1.46 mg kg−1) and wheat (1.32 ± 0.78 mg kg−1) grains, with rice containing ∼2-fold higher Ni content than wheat. Ni-RBA was low in soil (14.8 ± 7.79%, n = 18), but high in wheat and rice with rice Ni-RBA (85.9 ± 19.1%, n = 9) being ∼2-fold higher than wheat (46.1 ± 21.2%, n = 16). A negative correlation (r = 0.61) was observed between Ni-RBA and iron content in rice and wheat, suggesting the low iron status of rice drives its high Ni bioavailability. The higher Ni accumulation and bioavailability for rice highlights that rice consumption was a more important contributor to daily Ni intake compared to wheat, while Ni intake from direct soil ingestion was negligible. This study suggests a potential health risk of staple crops especially rice when grown in high geogenic Ni areas. Image 1 • Geogenic Ni exposure via food consumption and soil ingestion was assessed. • Elevated Ni was observed in soil and rice/wheat at a high geogenic Ni area. • Rice accumulated ∼2-fold higher Ni content than wheat when grown in rotation. • Oral bioavailability of rice-Ni was ∼2-fold higher than that of wheat-Ni. • Rice consumption was the predominant contributor to Ni exposure. Geogenic Ni exposure via food consumption and soil ingestion was assessed by analyzing Ni concentration and oral bioavailability in soil, wheat, and rice. [ABSTRACT FROM AUTHOR]

Dust storm (DS) represent global air pollution and health issues considering the high morbidity and premature death rate every year. This study explores the characteristics, composition, and variations in inhalable particulate matters (PMs) as well as their corresponding in vitro toxicity to human lung epithelial cells (A549) during DS and normal days (ND) in the downtown (DT) and the north suburban (NS) of Nanjing city, eastern China. Results showed that compared to ND, concentrations of heavy metals (i.e., Cr, Cu, Ni, and Pb) bound in PMs were lower during the DS. Furthermore, the relationship of cytotoxicity with Ni and Pb levels in PMs was significant. However, the cytotoxicity difference was insignificant between NS and DT. This may be due to the long-range transport of components from natural sources mixed with local pollutants emitted from anthropogenic sources, offsetting the pollution difference between urban and suburban areas. During both periods, PM 2.5 toxicity was greater than PM 10 , while the potential of PM 10 to induce proinflammatory cytokines was comparable to PM 2.5. Results suggested that inflammation risk will increase significantly during DS due to a substantial increase in ambient air PM 10 concentration. [Display omitted] [ABSTRACT FROM AUTHOR]

Fine particulates in city air significantly impact human health, but the hazardous compositional mechanisms are still unclear. Besides the toxicity of environmental PM 2.5 to in vitro human lung epithelial cells (A549), the independent cytotoxicity of PM 2.5 -bound water-soluble (WS-PM 2.5) and water-insoluble (WIS-PM 2.5) fractions were also compared by cell viability, oxidative stress (reactive oxygen species, ROS), and inflammatory injury (IL-6 and TNF-α). The cytotoxicity of PM 2.5 varied significantly by sampling season and place, with degrees greater in winter and spring than in summer and autumn, related to corresponding trend of air PM 2.5 level, and also higher in industrial than urban site, although their PM 2.5 pollution levels were comparable. The PM 2.5 bound metals (Ni, Cr, Fe, and Mn) may contribute to cellular injury. Both WS-PM 2.5 and WIS-PM 2.5 posed significant cytotoxicity, that WS-PM 2.5 was more harmful than WIS-PM 2.5 in terms of decreasing cell viability and increasing inflammatory cytokines production. In particular, industrial samples were usually more toxic than urban samples, and those from summer were generally less toxic than other seasons. Hence, in order to mitigate the health risks of PM 2.5 pollution, the crucial targets might be components of heavy metals and soluble fractions, and sources in industrial areas, especially during the cold seasons. [Display omitted] • Both soluble and insoluble-PM 2.5 induced cytotoxicity with source differences. • PM 2.5 toxicity was higher for industrial than urban area and cold than warm season. • Soluble than insoluble-PM 2.5 induced stronger cytotoxicity and inflammation. • Transition metals Ni, Cr, Fe, Mn might contribute to the different PM 2.5 toxicity. • Spatial-temporal sources and solubility are important for PM 2.5 health risk assessment. [ABSTRACT FROM AUTHOR]

Atmospheric fine particulate matter (PM 2.5) can harm human health, but the chemical composition and toxicity of PM 2.5 pollution might vary with weather conditions. In order to investigate the impacts of snowfall weather on aerosol characteristics and toxicity by changing particle sources and components, the daily PM 2.5 samples were collected before, during, and after a snowfall event in urban, industrial, suburban, and rural areas of Nanjing city in eastern China, for both chemical composition analysis and cytotoxicity tests. After 24 h exposure to these PM 2.5 , the cell activity, oxidative stress indicators and inflammatory factor expression levels of human lung epithelial cells A549 were measured by ELISA, and DNA damage was determined by comet assay. Although the concentrations of PM 2.5 in the air were reduced during snowfall, they posed stronger cytotoxicity, genetic toxicity and inflammatory responses to A549 cells. Related to the elevated mass concentrations of some components accumulated in PM 2.5 during snowfall, As, Co, Cr, Sr, V, water-soluble Na+ and Ca2+ showed positive correlations with toxicity indicators. Therefore, snowfall will clean air by deposition, but also make the PM 2.5 components remaining in air mostly anthropogenic by covering ground soil/dust, thus increase the particle's mass-based cytotoxicity and their health risks still cannot be ignored, such as the heavy metals and water-soluble ions from automobile exhaust and coal combustion. Unlabelled Image • Snowfall clean air but the rest PM 2.5 also pose significant health risks. • Natural soil/dust sources contribute less to PM 2.5 while snow covering ground. • PM 2.5 contain higher anthropogenic component proportion in snowing weather. • PM 2.5 during snowfall pose stronger mass-based cytotoxicity and genotoxicity. • Airborne heavy metals and water-soluble ions correlate positively with cell toxicity. [ABSTRACT FROM AUTHOR]

To test high cadmium (Cd) concentration may not be high in health risk when considering Cd bioavailability, we assessed variation of Cd relative bioavailability (RBA, relative to CdCl 2) using a mouse assay for 14 vegetables of water spinach, amaranth, and pakchoi. Cadmium concentration varied from 0.13 ± 0.01–0.37 ± 0.00 μg g–1 fw. Cadmium-RBA also varied significantly from 22.9 ± 2.12–77.2 ± 4.46%, however, the variation was overall opposite to that of Cd concentration, as indicated by a strong negative correlation between Cd-RBA and Cd concentration (R 2 = 0.43). Based on both Cd concentration and bioavailability, the identified high-Cd pakchoi variety resulted in significantly lower Cd intake than the high-Cd varieties of water spinach and amaranth (4.74 ± 0.05 vs. 10.1 ± 0.54 and 8.03 ± 0.04 μg kg–1 bw week–1) due to significantly lower Cd-RBA (22.9 ± 2.12 vs. 77.2 ± 4.46 and 51.3 ± 2.93%). The lower Cd-RBA in pakchoi was due to its significantly higher Ca and lower phytate concentrations, which facilitated the role of Ca in inhibiting intestinal Cd absorption. This was ascertained by observation of decreased Cd-RBA (90.5 ± 12.0% to 63.5 ± 5.53%) for a water spinach when elevating its Ca concentration by 30% with foliar Ca application. Our results suggest that to assess food Cd risk, both total Cd and Cd bioavailability should be considered. [Display omitted] • A strong negative correlation between Cd bioavailability and Cd concentration. • Pakchoi with higher Cd concentration was lower in health risk due to low Cd-RBA. • Higher Ca concentration was associated with lower Cd bioavailability. • High phytate in leafy vegetables contributed to high Cd bioavailability. • Calcium biofortification was effective to reduce Cd bioavailability. [ABSTRACT FROM AUTHOR]

Glyphosate [N-(phosphonomethyl)glycine] (GPS; H3G) is a widely used pesticide throughout the world. It affects metal behaviors in soil–plant system due to its functional groups, which react with metal ions to form metal complexes. Adsorption and cosorption of cadmium and glyphosate on a Wushan soil (WS soil, Anthrosol) and a Zhuanhong soil (ZH soil, Udic Ferrisol) as affect by solution pH were studied by means of batch adsorption experiments. It indicated that the adsorption quantity of Cd or glyphosate was highly relevant to soil characteristics. The WS soil had higher adsorption capacity of Cd than the ZH soil, due to its high organic matter content and cation exchange capacity (CEC). In contrast, the adsorption quantity of glyphosate on the WS soil was less than that on the ZH soil, because the WS soil has lower iron and aluminum oxides content but higher pH than the ZH soil. The herbicide glyphosate affected Cd adsorption on the two soils when they coexisted in a same soil solution, which was attributed to a glyphosate-induced pH-decrease and the corresponding decline in negative surface charges of the soil. Beside that, glyphosate reacted with solution Cd to form the water-soluble complexes that had lower affinity to soil surface in comparison with Cd itself. On the other hand, the presence of Cd in the soil solution also affected the adsorption of glyphosate on the soils. The presence of Cd increased adsorption quantity of glyphosate on the WS and ZH soils, which was resulted from the decrease of equilibrium solution pH caused by Cd2+ exchange with H+ ions of soil surface. In addition to that, glyphosate adsorption possibly takes place on sites where Cd was previously adsorbed and acted as a bridge between the soil and glyphosate. [Copyright &y& Elsevier]

Trace metal contamination prevails in various compartments of the urban environment. Understanding the roles of various anthropogenic sources in urban trace metal contamination is critical for pollution control and city development. In this study, the source contribution from various contamination sources to trace metal contamination (e.g. , Cu, Pb, Zn, Co, Cr and Ni) in different environmental compartments in a typical megacity, Guangzhou, southern China, was investigated using the receptor model (Absolute Principal Component Scores-Multiple Linear Regression, APCS-MLR) coupled with the Kriging technique. Lead isotopic data and APCS-MLR analysis identified industrial and traffic emissions as the major sources of trace metals in surface soil, road dust, and foliar dust in Guangzhou. Lead isotopic compositions of road dust and foliar dust exhibited similar ranges, implying their similar sources and potential metal exchange between them. Re-suspended soil contributed to 0–38% and 25–58% of the trace metals in the road dust and foliar dust, respectively, indicating the transport of the different terrestrial dust. Spatial distribution patterns implied that Cu in the road dust was a good indicator of traffic contamination, particularly with traffic volume and vehicle speed. Lead and Zn in foliar dust indicated mainly industrial contamination, which decreased from the emission source (e.g. , a power plant and steel factory) to the surrounding environment. The spatial influence of industry and traffic on the contamination status of road dust/foliar dust was successfully separated from that of other anthropogenic sources. This study demonstrated that anthropogenic inputs of trace metals in various environmental compartments (e.g. , urban soil, road dust, and foliar dust) can be evaluated using a combined APCS-MLR receptor model and geostatistical analysis at a megacity scale. The coupled use of APCS-MLR analysis, geostatistics, and Pb isotopes successfully deciphered the spatial influence of the contamination sources in the urban environment matrix, providing some important information for further land remediation and health risk assessment. Unlabelled Image • A systematic geochemical survey of trace metals in soil, road dust, and foliar dust in Guangzhou was conducted. • The spatially influence of anthropogenic sources on the contamination status of urban environment was evaluated. • Industrial and traffic emissions were the major sources of trace metals in Guangzhou. • Copper in road dust can be used as an indicator of traffic, while Pb and Zn in foliar dust reflected industrial sources. [ABSTRACT FROM AUTHOR]