Soil acidification has been expanding in many areas of Asia due to increasing reactive nitrogen (N) inputs and industrial activities. While the detrimental effects of acidification on forests have been extensively studied, less attention has been paid to grasslands, particularly alpine grasslands. In a soil pH manipulation experiment in the Qinghai-Tibet Plateau, we examined the effects of soil acidification on plant roots, which account for the major part of alpine plants.After three years of manipulation, soil pH decreased from 6.0 to 4.7 with the acid-addition gradient, accompanied by significant changes in the availability of soil nitrogen, phosphorus and cations. Plant composition shifted with the soil acidity, with graminoids replacing forbs. Differing from findings in forests, soil acidification in the alpine grassland increased root biomass by increasing the fraction of coarse roots and the production of fine roots, corresponding to enhanced sedge and grass biomass, respectively. In addition, litter decomposability decreased with altered root morphological and chemical traits, and soil acidification slowed root decomposition by reducing soil microbial activity and litter quality.Our results showed that acidification effect on root dynamics in our alpine grassland was significantly different from that in forests, and supported similar results obtained in limited studies in other grassland ecosystems. These results suggest an important role of root morphology in mediating root dynamics, and imply that soil acidification may lead to transient increase in soil carbon stock as root standing biomass and undecomposed root litter. These changes may reduce nutrient cycling and further constrain ecosystem productivity in nutrient-limiting alpine systems.

As an important component of organic carbon (OC), brown carbon (BrC) plays a significant role in radiative forcing in the atmosphere. Water-insoluble OC (WIOC) generally has higher light absorption ability than water-soluble OC (WSOC). The mass absorption cross-section (MAC) of WIOC is normally investigated by dissolving OC in methanol. However, all the current methods have shortcomings due to neglecting the methanol insoluble particulate carbon that is detached from the filter and suspended in methanol extracts, which results in MAC uncertainties of the methanol-soluble BrC and its climate warming estimation. In this study, by investigating typical biomass combustion sourced aerosols from the Tibetan Plateau and ambient aerosols from rural and urban areas in China, we evaluated the light absorption of extractable OC fraction for the existing methods. Moreover, a new method was developed to overcome the methanol insoluble particulate carbon detachment problem to achieve more reliable MAC values. We found that OC can be dissolved in methanol in a short time (e.g., 1 h) and ultrasonic treatment and long-term soaking do not significantly increase the extractable OC fraction. Additionally, we proved that methanol insoluble particulate carbon detachment in methanol does exist in previous methods, causing overestimation of the BrC mass extracted by methanol and thus the underestimation of MAC values. We therefore recommend the newly developed extraction method in this study to be utilized in future related studies to quantitatively obtain the light absorption property of methanol-soluble BrC.

Recent increased use of agricultural machines elevated the atmospheric pollutant emissions in the Yangtze River Delta (YRD) region in eastern China. Given the potentially large environmental and health impacts in busy seasons with enhanced machinery usage, it is important to accurately estimate the magnitude, spatial and temporal distributions of the emissions. We developed a novel method to estimate the real-world in-use agricultural machinery emissions, by combining satellite data, land and soil information, and in-house investigation. The machinery usage was determined based on the spatial distribution, growing and rotation pattern of the crops. The varied requirement of machinery power by heterogeneous soil texture, which was ignored in the previous studies, was considered in our methodology. The spatiotemporal pattern of machinery usage was determined based on the explored quantitative correlation between the local agricultural activity duration and the geographic location of the activity. A “grid-based” (30 × 30 m) inventory with daily emissions was then obtained, achieving significant improvement on spatial and temporal resolution. It substantially diminished the bias of previous inventories based on the machinery population or power installation census data. The emissions of NOX, PM₂.₅, CO and THC were estimated at 36300, 2000, 36900 and 8430 metric tons in YRD, with the majority contribution from Anhui and Jiangsu. Ten cities locating in northern and central Anhui and Jiangsu contributed the largest machinery emissions, accounting for 60% of the total emissions in YRD. Harvesting was found to have the largest emissions, followed by tilling and planting. Regarding the crops, the emissions from wheat and rice related machinery usage were the largest. In the busy seasons (spring and autumn), larger daily NOX and PM₂.₅ emissions were found from machinery than on-road vehicles in 42% of counties in Anhui and Jiangsu, highlighting the necessity of careful strategy making on controls of priority emission source.

As the number of Coronavirus Disease (2019) (COVID-19) cases increase globally, countries are taking more aggressive preventive measures against this pandemic. Transmission routes of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) include droplet and contact transmissions. There are also evidence of transmission through aerosol generating procedures (AGP) in specific circumstances and settings. Institutionalized populations without mobility and living in close proximity with unavoidable contact are especially vulnerable to higher risks of COVID-19 infection, such as the elderly in nursing homes, children in orphanages, and inmates in prisons. In these places, higher prevention and control measures are needed. In this study, we proposed prevention and control strategies for these facilities and provided practical guidance for general measures, health management, personal protection measures, and prevention measures in nursing homes, orphanages, and prisons, respectively.

Triclosan (TCS) and Triclocarbon (TCC) are chlorinated synthetic antimicrobial agents formaternal urinelated in quantities of consumer products. However, the biomonitoring of direct exposure reflection for fetuses are rare. In this study, we determine the concentrations of TCS and TCC in paired maternal serum, cord serum, maternal urine, and amniotic fluid samples collected from a cohort of 95 expecting mother-fetal pairs in Southern China. TCS and TCC are detected widely (detection rates: >76.9%) in maternal serum, cord serum, maternal urine, and amniotic fluid samples. TCS is found to be the predominant antimicrobial agent with median concentrations in maternal serum (1.5 ng/mL) and cord serum (1.8 ng/mL) that are one order of magnitude higher than those of tcc in maternal serum (0.085 ng/mL) and cord serum (0.052 ng/mL), respectively. Cord serum concentrations of tcs and tcc correlated well with the concentrations in maternal serum, which reflect the mothers’ contribution to fetal exposure. The higher median ratio of cord serum/maternal serumTCS (0.95) compared to that of cord serum/maternal serumTCC (0.53) indicates high placental transmission ability of TCS. Moreover, the facility to penetrate the placental barrier and hard to depurate characteristics lead to the long residence of TCS in the fetal environment, causing great concern over the prenatal exposure risks during the critical window of fetal development. This study provides a novel contribution by increasing existing knowledge on the exposure assessment of TCS and TCC during pregnancy through the exploration of matched maternal-fetal samples.

Recently, we reported that hypoxia disrupts the endocrine system and causes metabolic abnormalities in prawns. Although transgenerational impairment effects of hypoxia have become a hot topic in vertebrate, it is unknown whether hypoxia could exert cross-generational effects on testicular function crustaceans. The present study aimed to investigate hypoxia’s toxic effects on the testicular function of oriental river prawns (Macrobrachium nipponense) and offspring development. Hypoxia disrupted testicular germ cells quality, caused sex hormone imbalance (testosterone and estradiol), and delayed testicular development. The F1 generation derived from male prawns exposed to hypoxia showed retarded embryonic development, and reduced hatching success and larval development, despite not being exposed to hypoxia. Analysis of the transcriptome the F0 generation (exposed to hypoxia) showed that the impaired testicular functions were associated with changes to mitochondrial oxidative phosphorylation, apoptosis, and steroid biosynthesis. Interestingly, quantitative real-time PCR confirmed that hypoxia could significantly suppress the expression of antioxidant and gonad development-related genes in the testis of the F1 generations, with and without continued hypoxia exposures. In addition, paternal exposure to hypoxia could result in a higher production of reactive oxygen species in offspring testis tissue compared with those without hypoxia exposure. The cross-generational effects of testicular function implied that the sustainability of natural freshwater prawn populations would be threatened by chronic hypoxia.

Hydrophobic pollutants are still present in agricultural soil. The Cucurbitaceae family accumulates hydrophobic pollutants through roots, resulting in the contamination of aerial parts. Major latex-like proteins (MLPs), found in the Cucurbitaceae family, play an important role in the contamination by binding to these hydrophobic pollutants. Thus far, efficient cultivation methods for the production of safe crops with lower concentrations of hydrophobic pollutants have not been developed. Herein, we competitively inhibited the binding of MLPs to hydrophobic pollutants, pyrene and dieldrin, in roots by using MLP binding pesticides. By conducting a chemical array screening, we found that MLPs bound compounds with indole- and quinazoline-like structures. Commercially available pesticides amisulbrom and pyrifluquinazon, which possess such structures, successfully inhibited the binding of MLPs to pyrene and dieldrin in vitro. When zucchini plants were cultivated in the contaminated soil with 1.25 mmol/kg pyrene and 12.5 μmol/kg dieldrin, the concentration of pyrene and dieldrin in xylem sap was significantly decreased by 30% and 15%, respectively. Our results demonstrate that the pesticides binding to MLPs competitively inhibited the binding of MLPs to pyrene and dieldrin in roots, resulting in the reduction of overall contamination. This study proposes a novel approach to cultivate safer crops and advances the utilization of unknown functions of pesticides.

Tremendous efforts have been devoted by researchers on air particulate matter pollution for the increasing harm, however, the Air Pollution Index (API) from “good” to “excellent” is something hard to achieve. Here, halloysite nanotubes/polyvinyl alcohol (HNTs/PVA) hybrid membrane with surface micro-nano structure processing using a one-step method for efficient PM₂.₅ capture was prepared. The filtration efficiency is 45.35% and the pressure drop is 41.57 Pa of composite membrane with a 60 wt% halloysite dosage. Specially, it resulted in a relatively safer PM index value of about 16.54, which tends to be more stringent than the restriction by Government of China (PM₂.₅ < 35 μg/m³). The filtration performance was mainly attributed to the controllable microroughness surface as well as the hierarchical structure constructed by one-step method, which has a functional role in obstruction and adsorption for diluted PM₂.₅. The methodology can employ halloysite onto various polymers, like polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyacrylonitrile (PAN) and also polycaprolactone (PCL) to yield hybrid membranes with the similar modification of surface and structure. Such versatile membrane filters can be purposely designed and scaled up, which endows the existing hybrid membrane with great potentials in both residential and public areas pollution control to achieve a healthier living environment.

Microplastics (MPs) are a ubiquitous pollutant detected not only in marine and freshwater bodies, but also in tap and bottled water worldwide. While MPs have been extensively studied, the toxicity of their smaller counterpart, nanoplastics (NPs), is not well documented. Despite likely large-scale human and animal exposure to NPs, the associated health risks remain unclear, especially during early developmental stages. To address this, we investigated the health impacts of exposures to both 50 and 200 nm polystyrene NPs in larval zebrafish. From 6 to 120 h post-fertilization (hpf), developing zebrafish were exposed to a range of fluorescent NPs (10-10,000 parts per billion). Dose-dependent increases in accumulation were identified in exposed larval fish, potentially coinciding with an altered behavioral response as evidenced through swimming hyperactivity. Notably, exposures did not impact mortality, hatching rate, or deformities; however, transcriptomic analysis suggests neurodegeneration and motor dysfunction at both high and low concentrations. Furthermore, results of this study suggest that NPs can accumulate in the tissues of larval zebrafish, alter their transcriptome, and affect behavior and physiology, potentially decreasing organismal fitness in contaminated ecosystems. The uniquely broad scale of this study during a critical window of development provides crucial multidimensional characterization of NP impacts on human and animal health.

Methylmercury (MeHg) is a neurotoxic compound that is found in virtually all fish and biomagnifies in aquatic food webs. Although MeHg concentrations in marine and estuarine fish are often elevated, the impacts of MeHg on marine and estuarine fish have largely been understudied. To evaluate the impact of dietary MeHg on marine fish reproduction and effects on their offspring, female juvenile sheepshead minnows (Cyprinodon variegatus) at three months of age were experimentally exposed to MeHg-contaminated diets for two months and then paired with Hg-free males for spawning. Egg production, hatching success of embryos, time to hatching, survival of larvae, growth of larvae and swimming behavior of larvae were determined. Selenium (Se) was also measured and Se/Hg molar ratios were calculated to assess whether Se reduced MeHg toxicity. MeHg had no significant impact on fish reproduction or on survival and growth of larvae. Larvae produced by MeHg-exposed mothers had concentrations of Hg about 1 ppm (dry wt), or about 12% of that in the muscle of their mothers and consistently displayed 6–15% increased swimming speed relative to controls; the ecological significance of this moderate effect on swimming speed requires further study. The Se/Hg molar ratios in these fish, which were >1 in controls (adults and larvae) and MeHg-exposed larvae but <1 in Hg-exposed adults, did not correlate with MeHg effects. The sheepshead minnow, at a low trophic level, appears to have a high tolerance of MeHg; however, it can pass MeHg to higher trophic levels in marine ecosystems where upper level predators have MeHg concentrations sometimes exceeding US FDA safety limits of 1 ppm wet wt.