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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]

[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]

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]

Abstract: Solid/solution partition coefficient (K d) and speciation of soil heavy metals can be used for predicting their environmental risks. The K d values and solution speciation of soil Cu, Cd and Zn were analyzed in 40 samples of contaminated agricultural soils around Jiuhua copper mine in eastern Nanjing city, China. The K d ranges (and mean values) for soil Cu, Cd and Zn are 703–7418 (3453), 37.3–3963 (940) and 319–17965 (7244)Lkg−1, respectively, showing a large variability both for metals and soils. The results of differential pulse anodic stripping voltammetry (DPASV) indicates that 95.6% solution Cu is bound to dissolved organic ligands. About half of the dissolved Zn is DPASV-labile at pH<6, while 92.1% solution Zn is in the form of organic complexes at pH>6. DPASV-labile Cd is ranged from 22.6 to 98.7% with the mean value of 56.3%. Multiple linear regressions indicate that K d, the dissolved and DPASV-labile concentrations of Cd and Zn are mostly influenced by the soil solution pH with R 2 of 0.50, 0.59 and 0.63, respectively for Cd, and 0.58, 0.72 and 0.64, respectively for Zn. Considering the second parameter of corresponding soil metal, the linear relationships of K d with pH were improved with R 2 of 0.70 and 0.73 for Cd and Zn, respectively. However, the solubility of soil Cu was insensitive to pH. Only SOC shows a weak relationship to the dissolved Cu with R 2 of 0.21. As for its K d, total soil Cu is the most significant factor. But for DPASV-labile Cu, no soil parameters were found to be good predictors. [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]

Air pollution is a serious environmental issue. As a key aerosol component, PM 2.5 associated toxic trace metals pose significant health risks by inhalation and ingestion, but the evidences and mechanisms were insufficient and not well understood just by their total environmental concentrations. To accurately assess the potential risks of airborne metals, a series of in vitro physiologically based tests with synthetic human lung and gastrointestinal fluids were conducted to assess both the bioaccessibility and bioavailability of various PM 2.5 bound metals in the respiratory and digestive systems from both urban and industrial areas of Nanjing city. Moreover, the chemical acellular toxicity test [dithiothreitol (DTT) assay] and source analysis were performed. Generally, the bioaccessibility and bioavailability of investigated metals were element and body fluid dependent. Source oriented metals in PM 2.5 showed diverse bioaccessibility in different human organs. The PM 2.5 induced oxidative potential was mainly contributed by the bioaccessible/bioavailable transition metals such as Fe, Ni and Co from metallurgic dust and traffic emission. Future researches on the toxicological mechanisms of airborne metals incorporating the bioaccessibility, bioavailability and toxicity tests are directions. ga1 • Bioaccessibility and bioavailability of airborne metals were compared sequentially. • Metals dissolved in respiratory–digestive systems were element and fluid dependent. • Source-dependent PM 2.5 metals pose varied bioaccessibility/bioavailability in organs. • Bioaccessible/bioavailable transition metals induce PM 2.5 oxidative potential. • Metal bioaccessibility/bioavailability explain aerosol toxicity and health risks. [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]

Aerosol pollution is a serious environmental issue, especially in China where there has been rapid urbanization. To identify the intra-annual and regional distributions of health risks and potential sources of heavy metals in atmospheric particles with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5), this work collected monthly PM2.5 samples from urban, industrial, suburban, and rural areas in Nanjing city during 2016 and analyzed the heavy metal compositions (Cu, Pb, Cd, Co, V, Sr, Mn, Ti, and Sb). Enrichment factors (EFs) and principal component analysis (PCA) were applied to investigate the sources. The atmospheric PM2.5 pollution level was highest in the industrial area, followed by the urban and suburban areas, and was the lowest in the rural area. Seasonally, the concentrations of PM2.5 and associated heavy metals in spring and winter were higher than those in summer and autumn. Besides natural sources, heavy metal pollution in PM2.5 might come from metallurgical dust in the industrial area, while it mainly comes from automobile exhaust in urban and suburban areas. Health risk assessments revealed that noncancerous hazards of heavy metals in PM2.5 were low, while the lifetime cancer risks obviously exceeded the threshold. The airborne metal pollution in various functional areas of the city impacted human health differently. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM2.5) is a typical air pollutant and has adverse health effects across the world, especially in the rapidly developing China due to significant air pollution. The PM2.5 pollution varies with time and space, and is dominated by the locations owing to the differences in geographical conditions including topography and meteorology, the land use and the characteristics of urbanization and industrialization, all of which control the pollution formation by influencing the various sources and transport of PM2.5. To characterize these parameters and mechanisms, the 5-year PM2.5 pollution patterns of Jiangsu province in eastern China with high-resolution was investigated. The Kriging interpolation method of geostatistical analysis (GIS) and the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model were conducted to study the spatial and temporal distribution of air pollution at 110 sites from national air quality monitoring network covering 13 cities. The PM2.5 pollution of the studied region was obvious, although the annual average concentration decreased from previous 72 to recent 50 μg m−3. Evident temporal variations showed high PM2.5 level in winter and low in summer. Spatially, PM2.5 level was higher in northern (inland, heavy industry) than that in eastern (costal, plain) regions. Industrial sources contributed highest to the air pollution. Backward trajectory clustering and potential source contribution factor (PSCF) analysis indicated that the typical monsoon climate played an important role in the aerosol transport. In summer, the air mass in Jiangsu was mainly affected by the updraft from near region, which accounted for about 60% of the total number of trajectories, while in winter, the long-distance transport from the northwest had a significant impact on air pollution. [ABSTRACT FROM AUTHOR]

Organic pollutants are important harmful components in atmospheric fine particulate matters (PM 2.5), health risks of which varied with temporal and spatial distributions. To clarify the characteristics of atmospheric organic pollution, the concentrations, sources, and human health risks of typical organic compositions in PM 2.5 samples from both industrial and urban areas of Nanjing in eastern China were investigated monthly for a year. Results showed that, the concentrations of PM 2.5 -bound polycyclic aromatic hydrocarbons (PAHs) and n-alkanes were higher in winter and spring than those in summer and autumn. The organic pollution was slightly higher in industrial than urban area, though the PAHs in autumn and the n-alkanes in warm season (summer and autumn) were higher in urban area. With regards to the pollutant sources, the atmospheric PAHs were dominated by motor vehicle exhaust in the urban area, and combined with coal combustion emission in the industrial area. Airborne n-alkanes were mainly from biological source accompanied by fossil fuel combustion in industrial area. The PM 2.5 -bound PAHs indicated higher risks to adults in industrial area than in urban area with the seasonal patterns: winter > spring > autumn > summer. More attention should be paid to the health risks of exposure to organic pollutants accumulated in PM 2.5 during cold season. Controlling vehicle emissions might be the key measure for alleviating atmospheric PAHs and n-alkanes pollution in megacities, while coal purification can be an effective control method in industrial areas. • Organic pollutants are typical harmful components in PM 2.5 • Concentrations, sources, and health risks of PM 2.5 show spatio-temporal patterns. • PAHs and n-alkanes pollution were serious in cold season and industrial area. • Vehicle emission is a key target for alleviating particulate organic pollution. • Coal purification can be an effective pollution control method in industrial area. [ABSTRACT FROM AUTHOR]

Bioaerosols are a crucial part of atmospheric particulate matter (aerosols), combining physical and chemical aerosol properties with biological characteristics. They play a vital role in global ecosystems, climate change, air quality, and public health, and serve as an important pathway for transmitting respiratory infectious diseases. Major pandemics like H1N1, SARS, MERS, and COVID-19 have had far-reaching impacts on both human life and the global economy. Understanding the nexus 'sources-spatial and temporal distributions-influencing factors-health risks' of bioaerosols is crucial for developing strategies to mitigate pollution and prevent the spread of related epidemics. This review provides an overview of the primary sources of bioaerosols and their analysis methods, detailing the spatial and temporal distribution characteristics of their community structure across daily, annual, latitudinal gradient, vertical gradient, and urbanized environmental gradient variations. The study also elucidates the impact of land use types, meteorological conditions, climate change, and air quality on bioaerosols. It emphasizes the main exposure pathways, evaluation models, and constraints of pathogenic bioaerosols. Finally, this overview offers an outlook on the future development of bioaerosols and presents corresponding recommendations. [Display omitted] • The main source of pathogenic bioaerosols is anthropogenic. • The microbial indicator better tracks the migration of bioaerosols. • Bioaerosol fingerprints can more clearly specify their spatio-temporal distribution. • Urbanization and global warming may reduce the diversity of microbes in air. • Airborne pathogens are related to air pollution, climate change, and human activity. [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]

Behaviors of soil heavy metals are often affected by coexisting herbicides due to their physical and chemical interaction. Effect of glyphosate, an herbicide containing -PO_3^{2-} and -COOH groups, on cadmium adsorption in montmorillonite was studied in detail. The results showed that cadmium adsorption quantity in montmorillonite increased with increasing soil solution pH and cadmium concentration as usual, but decreased with glyphosate, which is due to the formation of a low affinity complex of Cd and glyphosate and decreasing solution pH induced by glyphosate addition. When the equilibrium solution pH was below 6.7, glyphosate has little effect on cadmium adsorption, but when the equilibrium solution pH was above 6.7, glyphosate significantly decreased cadmium adsorption quantity in montmorillonite. In addition, the adding order of Cd and glyphosate also influenced Cd adsorption quantity in montmorillonite. [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 determine the effectiveness of mineral dietary supplements to modulate cadmium (Cd) exposure, an in vivo mouse bioassay was conducted to determine Cd relative bioavailability (Cd-RBA) in Cd-contaminated rice (0.80 mg Cd kg-I) with and without Zn, Fe, or Ca supplements as nitrate or chloride salts. Without mineral supplements, Cd-RBA was 43 ± 5.3% based on average Cd accumulation in the liver plus kidneys as the end point. Among Ca(NO3)2, Zn(NO3)2, and Fe(NO3)2 supplements, 150-5000 mg kg-' Ca was the most effective in reducing rice Cd-RBA by 31-80% to 8.5-29%, while 30-200 mg kg-' Zn supplements was ineffective, with Cd-RBA being 33-57%. Low Fe at <40 mg kg-' had little impact on rice Cd-RBA (39-47%), while high Fe at 80-200 mg kg-' decreased Cd-RBA by 37% to 26-27%. The ineffectiveness of Zn supplements in reducing Cd-RBA was probably due to coinciding 83- and 3.1-fold increases in Zn accumulation in mouse kidneys and liver with Zn supplements, while Ca and Fe supplements led to much-smaller increases in Ca and Fe accumulation in mouse tissues (1.3-1.6 fold). In addition, compared to Ca(NO3)2 supplements, Cd-RBA values determined with CaCl2 supplements were significantly higher (25-67% versus 8.5-29%), suggesting that chloride enhanced Cd-RBA. Results of this study have important implications for developing effective dietary strategies to reduce dietary Cd exposure and the associated health risks in humans. [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]

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]