The estimation of PM₂.₅-related mortality is becoming increasingly important. The accuracy of results is largely dependent on the selection of methods for PM₂.₅ exposure assessment and Concentration-Response (C-R) function. In this study, PM₂.₅ observed data from the China National Environmental Monitoring Center, satellite-derived estimation, widely collected geographic and socioeconomic information variables were applied to develop a national satellite-based Land Use Regression model and evaluate PM₂.₅ exposure concentrations within 2013–2015 with the resolution of 1 km × 1 km. Population weighted concentration declined from 72.52 μg/m³ in 2013 to 57.18 μg/m³ in 2015. C-R function is another important section of health effect assessment, but most previous studies used the Integrated Exposure Regression (IER) function which may currently underestimate the excess relative risk of exceeding the exposure range in China. A new Shape Constrained Health Impact Function (SCHIF) method, which was developed from a national cohort of 189,793 Chinese men, was adopted to estimate the PM₂.₅-related premature deaths in China. Results showed that 2.19 million (2013), 1.94 million (2014), 1.65 million (2015) premature deaths were attributed to PM₂.₅ long-term exposure, different from previous understanding around 1.1–1.7 million. The top three provinces of the highest premature deaths were Henan, Shandong, Sichuan, while the least ones were Tibet, Hainan, Qinghai. The proportions of premature deaths caused by specific diseases were 53.2% for stroke, 20.5% for ischemic heart disease, 16.8% for chronic obstructive pulmonary disease and 9.5% for lung cancer. IER function was also used to calculate PM₂.₅-related premature deaths with the same exposed level used in SCHIF method, and the comparison of results indicated that IER had made a much lower estimation with less annual amounts around 0.15–0.5 million premature deaths within 2013–2015.

Chemical compositions of streambed biofilms from a major river of central Japan (the Kushida River) were obtained, with data of associated sediments (fine-grained fractions < 63 μm) and dissolved components of waters, in order to provide preliminary information about biogeochemical significance of streambed biofilms. During the sampling period (July 31st to August 3rd, 2013), dissolved components of the river waters were influenced by the dam reservoir. Concentrations of NO₃⁻, silica (as Si), SO₄²⁻, PO₄³⁻ and Ca²⁺ decreased across the dam, whereas Fe and Mn increased across the dam, and then decreased downstream rapidly. Streambed biofilms contain significant amount of non-nutrient elements such as Al (up to 21% as Al₂O₃ on water and others-free basis), indicating that they are contaminated as siliciclatic (silt and clay) materials. Siliciclastic materials in the biofilms are basically compositionally similar to fine-grained (<63 μm) fractions of streambed sediments. However, some elements such as Ca, P, Mn, and Zn are markedly enriched in the biofilms. Particularly, Mn concentrations in the biofilm samples collected just below the dam reservoir are very high (∼4.0 wt %), probably due to accumulation from the discharged water. Concentrations of trace elements such as P, Cr, Cu, Zn and V appear to be controlled by amounts of Fe-oxides and/or Mn-oxides in biofilms. Numbers of factors are involved in controlling chemical compositions of streambed biofilms, including amount of contaminated siliciclastics, authigenic mineral formation, adsorption of dissolved materials and microbial metabolisms. As demonstrated by this study, systematic analyses including major elements and comparison with associated sediments and waters could reveal biogeochemistry of this complex system.

The Sanjiang Plain, which is located in northeastern China, given the distribution of temperate freshwater wetlands there and this region has considerable significance in ensuring food security in China. Two periods of farmland reclamation that occurred during the last 100 years led to the loss of nearly 80% of the area of the native wetlands, and the development of agriculture has also increased the potential environmental risks to the residual wetlands. To evaluate the effects of farmland reclamation on the accumulation of key elements within the residual wetland ecosystems, six wetland profiles in the Sanjiang Plain are selected in this study. Using age-depth models and the concentrations of key elements, the historical accumulation rates (ARs) of carbon (C), nutrient elements (N and P) and potentially toxic elements (Hg, As, Pb, Cu, and Zn) over the last 150 years are reconstructed. The results show that the ARs of the potentially toxic elements in two of the wetland profiles begin to increase during the first reclamation period (AD 1900–1930). The ARs of both of the key elements clearly increase in all of the wetland profiles during the second reclamation period (AD 1950–1980). After land reclamation had ceased, increases in population and the development of industry became major factors that caused the potential environmental risks to wetlands to continue to increase from AD 1980 to the present. During the last 100 years, reclamation has increased the potential environmental risks and has led to the storage of additional carbon in the residual wetlands of the Sanjiang Plain.

Global water safety is facing great challenges due to increased population and demand. There is an urgent need to develop suitable water treatment strategy for small rural and remote communities in low-income developing countries. In order to find a low-cost solution, the reduction of E. coli using ceramic water disk coated with nano ZnO was investigated in this study. The performance of modified ceramic disk filters was influenced by several factors in the filter production process. Based on the factorial analysis, the pore size of the disk filters was the most significant factor for influencing E. coli removal efficiency and the clay content was the most significant one for influencing flow rate of modified disk filters. The coating of nano ZnO led to the change of disk filter surface and porosity. The reduction of E. coli could be attributed to both filter retention and photocatalytic antibacterial activity of nano ZnO. The effects of filter operation factors including initial E. coli concentration, illumination time and lamp power on E. coli removal effectiveness were also revealed. The results can help find a safe and cost-effective approach to solve drinking water problems in small rural and remote communities of developing regions.

The cyanobacterium Cylindrospermopsis raciborskii is of particular concern due to its ability to fix nitrogen (N), sporadic bloom, potential toxicity and apparent invasiveness. However, the toxicity associated behavior and response of toxic C. raciborskii under N fluctuations in water have been poorly investigated. The present study initiated based on the field survey in which Cylindrospermopsis species was found to have a high fitness under nitrate concentrations fluctuating from 0.02 mg L−1 to 2.90 mg L−1 in Chinese freshwater lakes. Examination on the role of short-term N fluctuations was conducted in two C. raciborskii strains which were exposed to a range of N concentrations supplied in two patterns, namely one-time pattern and ten-time pattern in which the equal amount of N was divided into ten-time accretions. The results showed the growth of both strains were not vulnerable to the transient nutrient fluctuations. The toxic strain showed considerable toxicological flexibility with the highest yield of cylindrospermopsin (CYN) obtained in the absence of N and the lowest in full medium. Generally, larger amounts of total CYN were observed at lower N levels, indicating that N deficiency promoted the intracellular accumulation and simultaneously restrained the extracellular release of CYN. Furthermore, CYN production was significantly different in two N supply patterns. The maximum quotas of intracellular and extracellular CYN in one-time pattern were respectively 2.79–3.53 and 3.94–7.20 times higher compared to the ten-time pattern. To our knowledge, our results are the first evidence of toxicity variations of C. raciborskii to the impermanent N fluctuations, shedding new light on its toxicological plasticity.

Microplastic polystyrene foam has been found widely in the environment and is readily transported by wind or water. Beached and virgin foams of size 0.45–1 mm were prepared as sorbents to study oxytetracycline sorption. Enhanced adsorption were found in the beached foams compared to the virgin foams, corresponding to the higher specific surface area, micropore area and the degree of oxidation of the former. The Freundlich Kf value was 894 ± 84 ((mg kg⁻¹) (mg L⁻¹)¹/ⁿ) for oxytetracycline adsorption on the beached foams, approximately twice as high as on the virgin foams. Effects of solution pH on adsorption to the beached foams were more pronounced to the virgin foams. Maximum adsorption occurred at pH 5 at which electrostatic repulsion between the microplastic surface and the oxytetracycline zwitterion was minimal, indicating that electrostatic interaction may have regulated adsorption. Moreover, H-bonding and multivalent cationic bridging mechanisms may also have affected the adsorption of oxytetracycline to the beached foams as reflected by the ionic effects. Adsorption was promoted more in the presence of humic acid than of fulvic acid, perhaps owing to π-π conjugation between the humic acid and the microplastic surface which led to enhanced electrostatic attraction for oxytetracycline. This study suggests that weathered polystyrene foams may act as carriers of antibiotics in the environment and their potential risks to ecosystem and human health merit further investigation.

Exposure to fine particulate matter (PM₂.₅) is one of the leading risk factors for the mortality and morbidity burden in India. Health benefit expected from mitigation of emissions from individual sectors is the key policy information to address this issue. Here we quantify the relative shares of four major year-round anthropogenic sources to ambient PM₂.₅ in India using a chemical transport model and estimate premature deaths that could have been avoided due to complete mitigation of emissions from these sources at state level. Population-weighted all-India averaged (±1σ) annual ambient PM₂.₅ exposures due to residential, transport, industrial and energy sectors in 2010 are estimated to be 26.2 ± 12.5, 3.8 ± 4.3, 5.5 ± 2.7 and 2.2 ± 2.3 μg m⁻³, respectively. Complete mitigation of emissions from the transport, industrial and energy sectors combined would avoid 92,380 (95% uncertainty interval (UI), 40,918–140,741) premature deaths annually, primarily at the urban hotspots. For the residential sector, this would result in avoiding 378,295 (95% UI, 175,002–575,293) premature deaths due to a reduction in ambient PM₂.₅ exposure in addition to the benefit of avoiding all premature deaths from household exposure. Bihar and Goa are expected to have the largest (289) and smallest (48) premature mortality burden per 100,000 population due to anthropogenic PM₂.₅ exposure. From policy perspective, controlling residential sources should be prioritized in view of the effectiveness of implementing mitigation measures and the expected larger health benefit at a regional scale. However, additional mitigation measures are advised at the urban hotspots to curb emissions from the other sectors to get maximum possible health benefit.

A long-lasting high particulate matter (PM) concentration episode persisted over East Asia from May 24 to June 3, 2014. The Nested Air Quality Prediction Model System (NAQPMS) was used to investigate the mixing of dust and anthropogenic pollutants during this episode. Comparison of observations revealed that the NAQPMS successfully reproduced the time series PM₂.₅ and PM₁₀ concentrations, as well as the nitrate and sulfate concentrations in fine (aerodynamic diameter ≤ 2.5 μm) and coarse mode (2.5 μm < aerodynamic diameter ≤ 10 μm). This episode originated from two dust events that occurred in the inland desert areas of Mongolia and China, and then the long-range transported dust and anthropogenic pollutants were trapped over the downwind region of East Asia for more than one week due to the blocked north Pacific subtropical high-pressure system over the east of Japan. The model results showed that mineral dust accounted for 53–83% of PM₁₀, and 39–67% of PM₂.₅ over five cities in East Asia during this episode. Sensitivity analysis indicated that the Qingdao and Seoul regions experienced dust and pollution twice, by direct transport from the dust source region and from dust detoured over the Shanghai area. The results of the NAQPMS model confirmed the importance of dust heterogeneous reactions (HRs) over East Asia. Simulated dust NO₃⁻ concentrations accounted for 75% and 84% of total NO₃⁻ in fine and coarse mode, respectively, in Fukuoka, Japan. The horizontal distribution of model results revealed that the ratio of dust NO₃⁻/dust concentration increased from about 1% over the Chinese land mass to a maximum of 8% and 6% respectively in fine and coarse mode over the ocean to the southeast of Japan, indicating that dust NO₃⁻ was mainly formed over the Yellow Sea and the East China Sea before reaching Japan.

Rivers in the arid Western United States face increasing influences from anthropogenic contaminants due to population growth, urbanization, and drought. To better understand and more effectively track the impacts of these contaminants, biologically-based monitoring tools are increasingly being used to complement routine chemical monitoring. This study was initiated to assess the ability of both targeted and untargeted biologically-based monitoring tools to discriminate impacts of two adjacent wastewater treatment plants (WWTPs) on Colorado's South Platte River. A cell-based estrogen assay (in vitro, targeted) determined that water samples collected downstream of the larger of the two WWTPs displayed considerable estrogenic activity in its two separate effluent streams. Hepatic vitellogenin mRNA expression (in vivo, targeted) and NMR-based metabolomic analyses (in vivo, untargeted) from caged male fathead minnows also suggested estrogenic activity downstream of the larger WWTP, but detected significant differences in responses from its two effluent streams. The metabolomic results suggested that these differences were associated with oxidative stress levels. Finally, partial least squares regression was used to explore linkages between the metabolomics responses and the chemical contaminants that were detected at the sites. This analysis, along with univariate statistical approaches, identified significant covariance between the biological endpoints and estrone concentrations, suggesting the importance of this contaminant and recommending increased focus on its presence in the environment. These results underscore the benefits of a combined targeted and untargeted biologically-based monitoring strategy when used alongside contaminant monitoring to more effectively assess ecological impacts of exposures to complex mixtures in surface waters.

Recently it has been shown that there are two types of magnetite particles in the human brain, some, which occur naturally and are jagged in appearance, and others that arise from industrial sources, such as coal fired power plants, and are spherical. In order to confirm the latter, the magnetic component of coal ash is first purified and characterized by XRD, showing that it is magnetite with an average particle size of 211 nm. Studies confirm the coal ash magnetic behavior, and that the magnetite is not bound to the other components of coal ash but exist as an isolatable component. SEM studies confirm that in the process of burning coal at very high temperatures for industrial uses, the magnetite formed is spherically shaped, as recent studies of brain tissues of highly exposed urban residents have found. As such, the use of coal for industrial applications such as coking in the production of steel and in power plants is indicated to be a major source of the spherical magnetic combustion-associated magnetite fine particle and nanoparticle environmental pollution. The capacity of these magnetic particles to penetrate and damage the blood-brain-barrier and the early development of Alzheimer's disease hallmarks in exposed populations calls for detail analysis of magnetic fine and nanoparticle distribution across the world.Summation: Industrial coal usage produces spherical magnetic particles and nanoparticles, identical to those associated with neurological disorders.