Environmental Research最新文献

Background

Previous studies have shown that urban neighborhood environmental factors significantly influence the health outcomes of urban older adults. However, most cross-sectional studies exploring the health effects of these factors have failed to quantify the relative importance of each factor.

Methods

We use XGBoost machine learning techniques and SHAPley Additive Interpretation (SHAP) to rank the importance of urban neighborhood environmental factors in shaping the mental health of urban older adults. To address self-selection bias in housing choice, we distinguish older adults living in private housing from those living in public as residents in private housing have more freedom to choose where to live.

Results

The results show that both natural and built environmental factors in urban neighborhoods are important predictors of mental well-being scores. Five natural environmental factors (blue space, perceived greenery quantity, NDVI, street view greenness, aesthetic quality) and three built environmental factors (physical activity facilities quality, physical activity facilities quantity, neighborhood disorder) had considerable predictive power for mental well-being scores in two groups. Among them, blue space, perceived greenery quantity and street view greenness quantity became less important after controlling for self-selection bias, possibly because of the unequal distribution of quantity and quality, and the performance of neighborhood disorder, aesthetic quality and physical activity facilities quality was more sensitive in public housing.

Conclusions

These results highlight the nuanced and differential effects of neighborhood environmental exposures on mental well-being outcomes, depending on housing preferences. The results of this study can provide support for decision makers in urban planning, landscape design and environmental management in order to improve the mental well-being status of urban older adults.

Vacuum collected toilet wastewater (VCTW) contains high and fluctuating contents of organics and nitrogen, which exerts technological challenges to biological treatment processes. A partial nitrification–denitrification and anammox (PND-AMX) process was developed in sequencing batch reactor (SBR) and moving bed biofilm reactor (MBBR) to achieve effective nitrogen removal in VCTW at low ambient temperature. Stable PND was achieved, and nitrogen removal efficiency in SBR could be manipulated by adjusting influent COD/N ratios. As temperature ≥18 °C, 91.0% nitrogen was removed in PND-AMX process. In spite of the decreased anammox activity at 13–18 °C, more than 90% nitrogen removal could be obtained by adjusting SBR influent COD/N to 2.43 ± 0.32 with methanol. In MBBR reactor, Candidatus Kuenenia was the dominant anammox bacteria and contributed to more than 90% nitrogen removal capacity. Co-existing anammox and denitrifying bacteria synergistically contributed to the removal of ammonium, nitrite, nitrate, and COD in MBBR.

Microplastics (MPs) pollution has raised serious environmental concerns due to its widespread generation and discharge across global ecosystems. It is estimated that approximately 400 million metric tons of plastic are produced annually, with 54% ending up as waste. The MPs account for a significant portion of this pollution. These MPs interact with heavy metals (HMs) in terrestrial ecosystems, such as cadmium (Cd), lead (Pb), and arsenic (As), which are introduced through various industrial activities at rates of thousands of tons per year. Such interactions may cause synergistic or antagonistic effects on plants. Recent studies suggest that MPs and HMs exposure impacts various physiological and biochemical pathways in plants, thereby increasing the toxicity symptoms. However, the existing scholarly understanding of the coupled effect of HMs and MPs on plants is limited, highlighting the need to explore these complex dynamics further. Through a comprehensive analysis of current research, this review underscores various pathways of MPs and HMs infiltration mechanisms, detailing their penetration, translocation, and bioaccumulation within plants. The physiological and biochemical effects of both pollutants on plants are deliberated individually and in combination. The review reveals that the co-existence of these contaminants results in a multifaceted environmental challenge, affecting overall plant growth, yield, and quality in ways that differ from individual exposure. Building on recent advancements, this article is expected to delineate the complex interactions between MPs, HMs, and plants and enhance the current understanding of the intricate interplay between them.

Reed (Phragmites australis) dominated wetlands are commonly known as strong carbon (C) sinks due to the high productivity of the reed plant and C fixation in the wetland soil. However, little is known about the effects of drought on reed-dominated wetlands and the possibility of Pannonian reed ecosystems being a source of greenhouse gases (GHG). The drought at Lake Neusiedl had a particular impact on the water level, but also had consequences for the reed belt. Therefore, we investigated the drought-influenced C fluxes and their drivers in the reed ecosystem of this subsaline lake over a period of 4.5 years (mid-2018 to 2022). We applied eddy covariance technique to continuously quantify the vertical turbulent GHG exchange between reed belt & atmosphere and used vegetation indices to account for reed growth. Methane emissions decreased by 76% from 9.2 g CH₄-C m^-2a^-1 (2019) to 2.2 g CH₄-C m^-2 a^-1 (2022), which can be explained by the falling water level, the associated drying out of the reed belt and its consequences. Carbon dioxide emissions initially decreased by 85% from 181 g CO₂-C m^-2 a^-1 (2019) to 27 g CO₂-C m^-2 a^-1 (2021), but then increased to twice the 2019 level in 2022 (391 g CO₂-C m^-2 a^-1). Due to the drying reed belt, the reed initially grew into formerly water-covered areas within the reed belt, especially in 2021, leading to higher photosynthesis through 2021. This development stopped and even reversed in 2022 as a consequence of the sharp decrease in sediment water content from about 65 to 32 Vol-% in mid-2022. Overall, drought led to a decoupling of the reed ecosystem from the open lake area and developed the wetland into a strong C source.

Technological change has affected human health dating back to at least the Neolithic agricultural revolution. Growing evidence indicates widespread environmental pollution began with metallurgical practices and continues today. Environmental exposures to trace elements released from these practices have the potential to alter human body composition, such as bone mineral chemistry, especially for elements that are not homeostatically regulated. These signals can be used for inferences about human health, particularly when metallotoxins are detected in abundance. Therefore, trace element geochemistry of archaeological bone may provide a means to evaluate human health through time. However, diagenetic factors can hinder attempts to extract this information. Thus, we employed advanced analytical and interpretive methods to carefully distinct groups of European burials over about 1000 years to address questions of potentially toxic trace element exposures. Here, to address our hypothesis that Roman urbanization created one of the earliest urban toxic environment caused by multiple exposures, we present a comprehensive suite of bone trace element compositions of femora from burials spanning three distinct archaeological time periods (Bronze Age, Iron Age, and Roman period). All bone specimens were obtained from the anterior-mid shaft of carefully selected femora and processed using the same analytical techniques designed to mitigate soil contamination. Our data indicate that widespread environmental pollution accelerated in Londinium during the Roman Empire period, leading to conditions where population health would be vulnerable to environmental changes. Specifically, bone lead, silver, vanadium, arsenic, and cadmium concentrations were typically elevated and would likely be associated with multiple toxicities. In addition, bone iron levels were extremely high in some Londinium burials. Our interpretation is that the Romans inhabiting Londinium were not just poisoned by lead exposure as several previous studies show but by several metallotoxins.

Particle size effects significantly impact the concentration and toxicity of heavy metals (HMs) in dust. Nevertheless, the differences in concentrations, sources, and risks of HMs in dust with different particle sizes are unclear. Therefore, guided by the definition of atmospheric particulate matter, dust samples with particle sizes under 1000 μm (DT₁₀₀₀), 100 μm (DT₁₀₀), and 63 μm (DT₆₃) from Beijing kindergartens were collected. The concentrations of HMs (e.g., Cd, Pb, Zn, Ni, Cr, Ba, Cu, V, Mn, Co, and Ti) in dust samples with different particle sizes were measured. Besides, the differences in HM concentrations, contamination levels, sources, and source-oriented health risks in dust samples of different particle sizes were systematically explored. The results show that the concentrations of Mn, V, Zn, and Cd gradually increase with decreasing dust particle sizes, the concentrations of Ba and Pb show a decreasing trend, and the concentrations of Cr, Cu, Ni, and Co display an increasing and then decreasing trend. The degree of contamination of HMs in dust of different particle sizes varies, with Cd being the most dominant contaminant. Compared with DT₁₀₀₀ and DT₆₃, DT₁₀₀ is the most polluted. In addition, the sources of HMs in DT₁₀₀₀, DT₁₀₀, and DT₆₃ become more single with decreasing particle size, which may be mainly due to the particle-size effect inducing the redistribution of HMs in different sources. Notably, the potential health risk is higher in DT₁₀₀ than in DT₁₀₀₀ and DT₆₃. The highest contribution of industrial sources to the health risk is found in DT₁₀₀, which is mainly caused by highly toxic chromium (Cr). This work emphasizes the importance of considering particle size in risk assessment and pollution control, which can provide a theoretical basis for precise management of HMs pollution in dust.

Fertilization is a critical agronomic measure for croplands in tropical regions, owing to their low fertility. However, the effects of fertilization on the quantity and chemodiversity of latosolic dissolved organic matter (DOM) in tropical regions remain largely unknown. Therefore, in this study, the variations in latosol DOM concentrations and chemodiversity induced by inorganic fertilization and the co-application of inorganic fertilization with straw return, sheep manure, biochar, and vermicompost fertilizers at a molecular level were systematically investigated using multispectral techniques and ultrahigh-resolution mass spectrometry. In line with our expectations, the results showed that combined inorganic-organic fertilization improved soil quality by increasing soil organic carbon content compared to that under inorganic fertilization. However, as the most active and bioavailable organic carbon pool, dissolved organic carbonconcentrations between the fertilization treatments were not significantly different (p = 0.07). However, the dissolved organic carbon concentrations under combined inorganic-organic fertilization treatment (NPK plus straw return, 263.45 ± 37.51 mg/kg) were lower than those under inorganic fertilization treatment (282.10 ± 18.57 mg/kg). Spectral analysis showed that the DOM in the combined inorganic-organic fertilization treatments had a higher degree of humification and lower autogenetic contributions. Furthermore, Fourier transform ion cyclotron resonance mass spectrometry analysis indicated that the combined inorganic-organic fertilization increased the chemodiversity of latosolic DOM and promoted the production of large, oxidized, and stable molecules, including lignin, aromatic, and tannin compounds, which potentially benefits soil carbon sequestration in tropical regions. This study could provide a theoretical basis for elucidating on the potentially relevant ecological functions and environmental effects of DOM under fertilization regimes.

Due to metal toxicity, widespread industrialization has negatively impacted crop yield and soil quality. The current study was aimed to prepare and characterize biochar made from wood shavings of Pinus roxburghii and to determine the plant growth promoting and heavy metal detoxification of cadmium (Cd) and chromium (Cr) contaminated soil. FTIR SEM coupled with EDX characterization of biochar was performed; Cd and Cr were used at a rate of 20 mg/kg. Biochar was used at the rate of 50 mg/kg for various treatments. The completely randomized design (CRD) was used for the experiment and three replicates of each treatment were made. Various agronomic and enzymatic parameters were determined. The results indicated that all growth and enzymatic parameters were enhanced by the prepared biochar treatments. The most prominent results were observed in treatment T5 (in which shoot length, root length, peroxidase dismutase (POD), superoxide dismutase (SOD) catalyzes (CAT), and chlorophyll a and b increased by 28%, 23%, 40%, 41%, 42%, and 27%, respectively, compared to the control). This study demonstrated that biochar is a sustainable and cost-effective approach for the remediation of heavy metals, and plays a role in plant growth promotion. Farmers may benefit from the current findings, as prepared biochar is easier to deliver and more affordable than chemical fertilizers. Future research could clarify how to use biochar optimally, applying the minimum amount necessary while maximizing its benefits and increasing yield.

Cyanobacteria represent a promising resource for sustainable agriculture, as they have demonstrated the ability to restore soil fertility even after death and decay. However, several cyanobacteria can also release secondary metabolites, such as cyanotoxins, which may compromise the quality of agricultural products and pose a potential risk to human health. Depending on the concentration of exposure, few studies reported deleterious effects on plant species when irrigated with cylindrospermopsin (CYN) contaminated water, impairing plant growth and leading to food product contamination, while other studies show promoting effects on plant yield. To evaluate the potential of cyanobacterial biomass (cyanotoxin-containing or not) as a sustainable resource for soil amendment, biostimulants or fertilizers for lettuce cultivation, a study was carried out that consisted of the culture of lettuce plants under controlled conditions, in soil: (1) with no extra nutrient addition (control) and supplemented with 0.6 g of freeze-dried Raphidiopsis raciborskii biomass of (2) a non-CYN-producing strain, (3) a CYN-producing strain, and (4) the same CYN-producing strain pasteurized. Results showed no significant differences in photosystem II efficiency with the amendment addition. On the contrary, shoot fresh weight significantly increased in lettuce plants grown with the cyanobacterial biomass addition, especially in condition (3). In addition, there were significant differences in mineral concentrations in lettuce leaves after the cyanobacterial biomass addition, such as K, Na, Ca, P, Mg, Mn, Zn, Cu, Mo, and Co. CYN accumulation was detected under conditions (3) and (4), with concentrations observed in descending order from roots > soil > shoot. Nevertheless, the CYN concentration in edible tissues did not exceed the WHO-proposed tolerable daily intake of 0.03 μg/kg/day. These findings suggest that incorporating cyanobacterial biomass as a soil amendment, biostimulant or fertilizer for lettuce cultivation, even with trace amounts of CYN (1–40 μg/g), may enhance plant yield without leading to cyanotoxin accumulation in edible tissues above the WHO-recommended tolerable daily intake.

Greenhouse gas (GHG) emissions from streams and rivers are important sources of global GHG emissions. As a crucial parameter for estimating GHG emissions, the gas transfer coefficient (expressed as K₆₀₀ at water temperature of 20 °C) has uncertainties. This study proposed a new approach for estimating K₆₀₀ based on high-frequency dissolved oxygen (DO) data and an ecosystem metabolism model. This approach combines the numerical solution method with the Markov Chain Monte Carlo analysis. This study was conducted in the Chaohu Lake watershed in Southeastern China, using high-frequency data collected from six streams from 2021 to 2023. This study found: (1) The numerical solution of K₆₀₀ demonstrated distinct dynamic variability for all streams, ranging from 0 to 111.39 cm h⁻¹ (2) Streams with higher discharge (>10 m³ s⁻¹) exhibited significant seasonal differences in K₆₀₀ values. The monthly average discharge and water temperature were the two factors that determined the variation in K₆₀₀ values. (3) K₆₀₀ was a major source of uncertainty in CO₂ emission fluxes, with a relative contribution of 53.72%. An integrated K₆₀₀ model of riverine gas exchange was developed at the watershed scale and validated using the observed DO change. Our study stressed that K₆₀₀ dynamics can better represent areal change to reduce uncertainty in estimating GHG emissions.