Multiple contaminants can affect plant-microbial remediation processes because of their interactive effects on environmental behaviour, bioavailability and plant growth. Recent studies have suggested that arbuscular mycorrhizal fungi (AMF) can facilitate the revegetation of soils co-contaminated with rare earth elements (REEs) and heavy metals. However, little is known regarding the role of AMF in the interaction of REEs and heavy metals. A pot experiment was conducted to evaluate the effects of Claroideoglomus etunicatum on the biomass, nutrient uptake, metal uptake and translocation of maize grown in soils spiked with Lanthanum (La) and Cadmium (Cd). The results indicated that individual and combined applications of La (100 mg kg−1) and Cd (5 mg kg−1) significantly decreased root colonization rates by 22.0%–35.0%. With AMF inoculation, dual-metal treatment significantly increased maize biomass by 26.2% compared to single-metal treatment. Dual-metal treatment significantly increased N, P and K uptake by 20.1%–76.8% compared to single-metal treatment. Dual-metal treatment significantly decreased shoot La concentration by 52.9% compared to single La treatment, whereas AM symbiosis caused a greater decrease of 87.8%. Dual-metal treatment significantly increased shoot and root Cd concentrations by 65.5% and 58.7% compared to single Cd treatment and the La translocation rate by 142.0% compared to single La treatment, whereas no difference was observed between their corresponding treatments with AMF inoculation. Furthermore, AMF had differential effects on the interaction of La and Cd on metal uptake and translocation under the background concentrations of soil metals. Taken together, these results indicated that AMF significantly affected the interaction between La and Cd, depending on metal types and concentrations in soils. These findings promote a further understanding of the contributions of AMF to the phytoremediation of co-contaminated soil.

Homosalate is an organic ultraviolet filter used in most sunscreens but has been reported to be toxic to marine organisms. The estrogenic activity of homosalate has also been reported, but its endocrine-disrupting effect remains unclear. Although homosalate has been detected in human placental tissues, its effect on the survival of human trophoblast cells needs to be investigated. Therefore, in this study, we evaluated if HTR8/SVneo, a human trophoblast cell line, treated with homosalate showed decreasing proliferative activity in a dose-dependent manner. Homosalate promoted the death of HTR8/SVneo cells with elevated lipid peroxidation and intracellular Ca²⁺ concentration. It also induced endoplasmic reticulum stress and mitochondrial morphological disturbances associated with the differentiation of human trophoblast cells. However, when the intracellular Ca²⁺ or reactive oxygen species were removed using BAPTA-AM or N-acetyl-L-cysteine (NAC), the cell proliferation suppressed by homosalate was restored. Homosalate also significantly inhibited the invasion of HTR8/SVneo cells. Furthermore, it modulated phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signaling pathways, which were involved in the cross-talk between both signaling pathways in HTR8/SVneo cells. Thus, homosalate adversely affects the survival, proliferation, and invasiveness of human trophoblast cells and therefore pregnant women should practice caution while using personal care products containing homosalate.

As a transitional zone between riverine and marine environments, an estuary plays an important role for the sources, accumulation and transport of microplastics. Although estuarine environments are hotspots of microplastic pollution, the correlation between microplastic pollution and aquatic organisms is less known. Here we investigated microplastic pollution in wild oysters Saccostrea cucullata from 11 sampling sites along the Pearl River Estuary in South China. The microplastic abundances in oysters ranged from 1.4 to 7.0 items per individual or from 1.5 to 7.2 items per gram tissue wet weight, which were positively related to those in surrounding waters. The oysters near urban areas contained significantly more microplastics than those near rural areas. Fibers accounted for 69.4% of the total microplastics in oysters. Microplastic sizes varied from 20 to 5000 μm and 83.9% of which were less than 100 μm. Light color microplastics were significantly more common than dark color ones. Based on the results, oysters are recommended as a biomonitor for the microplastic pollution in estuaries.

The present study combines high-resolution measurements at various distances from a world-class gigantic petrochemical complex with model simulations to test a method to assess industrial emissions and their effect on local air quality.Due to the complexity in wind conditions which were highly seasonal, the dominant wind flow patterns in the coastal region of interest were classified into three types, namely northeast monsoonal (NEM) flows, southwest monsoonal (SEM) flows and local circulation (LC) based on six years of monitoring data. Sulfur dioxide (SO2) was chosen as an indicative pollutant for prominent industrial emissions. A high-density monitoring network of 12 air-quality stations distributed within a 20-km radius surrounding the petrochemical complex provided hourly measurements of SO2 and wind parameters. The SO2 emissions from major industrial sources registered by the monitoring network were then used to validate model simulations and to illustrate the transport of the SO2 plumes under the three typical wind patterns. It was found that the coupling of observations and modeling was able to successfully explain the transport of the industrial plumes. Although the petrochemical complex was seemingly the only major source to affect local air quality, multiple prominent sources from afar also played a significant role in local air quality. As a result, we found that a more complete and balanced assessment of the local air quality can be achieved only after taking into account the wind characteristics and emission factors of a much larger spatial scale than the initial (20 km by 20 km) study domain.

Microplastics exposure could be detrimental to marine organisms especially under high concentrations. However, few studies have considered the multiphasic nature of marine invertebrates' life history and investigated the impact of experiencing microplastics during early development on post-metamorphic stages (legacy effect). Many planktonic larvae can feed selectively and it is unclear whether such selectivity could modulate the impact of algal food-sized microplastic. In this two-stage experiment, veligers of Crepidula onyx were first exposed to additions of algae-sized micro-polystyrene (micro-PS) beads at different concentrations, including ones that were comparable their algal diet. These additions were then either halted or continued after settlement. At environmentally relevant concentration (ten 2-μm microplastic beads ml⁻¹), larval and juvenile C. onyx was not affected. At higher concentrations, these micro-PS fed larvae consumed a similar amount of algae compared to those in control but grew relatively slower than those in the control suggesting that ingestion and/or removal of microplastic was/were energetically costly. These larvae also settled earlier at a smaller size compared to the control, which could negatively affect post-settlement success. Juvenile C. onyx receiving continuous micro-PS addition had slower growth rates. Individuals only exposed to micro-PS during their larval stage continued to have slower growth rates than those in the control even if micro-PS had been absent in their surroundings for 65 days highlighting a legacy effect of microplastic exposure.

The use of DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane) in some countries, although regulated, is contributing to an increased worldwide risk of exposure to this organochlorine pesticide or its derivative p,p’-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene]. Many studies have associated p,p’-DDE exposure to type 2 diabetes, obesity and alterations of the reproductive system, but their molecular mechanisms of toxicity remain poorly understood. We have addressed this issue by using commercial microarrays based on probes for the entire Mus musculus genome to determine the hepatic transcriptional signatures of p,p’-DDE in the phylogenetically close mouse species Mus spretus. High-stringency hybridization conditions and analysis assured reliable results, which were also verified, in part, by qRT-PCR, immunoblotting and/or enzymatic activity. Our data linked 198 deregulated genes to mitochondrial dysfunction and perturbations of central signaling pathways (kinases, lipids, and retinoic acid) leading to enhanced lipogenesis and aerobic glycolysis, inflammation, cell proliferation and testosterone catabolism and excretion. Alterations of transcript levels of genes encoding enzymes involved in testosterone catabolism and excretion would explain the relationships established between p,p´-DDE exposure and reproductive disorders, obesity and diabetes. Further studies will help to fully understand the molecular basis of p,p´-DDE molecular toxicity in liver and reproductive organs, to identify effective exposure biomarkers and perhaps to design efficient p,p’-DDE exposure counteractive strategies.

The biodegradation of low- and high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) (LWM-PAHs and HMW-PAHs, respectively) has been studied extensively under aerobic conditions. Molecular O₂ plays 2 critical roles in this biodegradation process. O₂ activates the aromatic rings through hydroxylation prior to ring opening and serves as a terminal electron acceptor (TEA). However, several microorganisms have devised ways of activating aromatic rings, leading to ring opening (and thus biodegradation) when TEAs other than O₂ are used (under anoxic conditions). These microorganisms belong to the sulfate-, nitrate-, and metal-ion-reducing bacteria and the methanogens. Although the anaerobic biodegradation of monocyclic aromatic hydrocarbons and LWM-PAH naphthalene have been studied, little information is available about the biodegradation of HMW-PAHs. This manuscript reviews studies of the anaerobic biodegradation of HMW-PAHs and identifies gaps that limit both our understanding and the efficiency of this biodegradation process. Strategies that can be employed to overcome these limitations are also discussed.

The concentrations of Cd, Cr and Pb in soil samples and As, Cd, Cr and Pb in plant specimens were analyzed in an arid area in central Iran. Plants were categorized into desert-adapted (Haloxylon ammodendron, Atraphaxis spinosa and Artemisia persica) and non-desert species. It was found that the trace element (TE) accumulating potential of the desert species (Haloxylon ammodendron and Artemisia persica) with a mean value of 0.1 mg kg⁻¹ for Cd was significantly higher than that of the majority of the non-desert species with an average of 0.05 mg kg⁻¹. Artemisia also had a high As accumulating capability with a mean level of 0.8 mg kg⁻¹ in comparison with an average of 0.2 mg kg⁻¹ for most of the other plant species. The mean values of Cr and Pb in Haloxylon ammodendron and Artemisia persica were 5 and 3 mg kg⁻¹, respectively. Among the desert-adapted plants, Atraphaxis proved to be a species with high Cr and Pb accumulating potential, as well. The geoaccumulation index and the overall pollution scores indicated that the highest environmental risk was related to Cd. Different statistical analyses were used to study the spatial patterns of soil Cd and their connections with pollution sources. The variogram was estimated using a classical approach (weighted least squares) and was compared with that of the posterior summaries that resulted from the Bayesian technique, which lay within the 95% Bayesian credible quantile intervals (BIC) of posterior parameter distributions. The prediction of cadmium values at un-sampled locations was implemented by multi-Gaussian kriging and sequential Gaussian simulation methods. The prediction maps showed that the region most contaminated by Cd was the north-eastern part of the study area, which was linked to mining activities, while agricultural influence contributed less in this respect.

Congenital heart defects (CHDs) are a major cause of death in infancy and childhood. Major risk factors for most CHDs, particularly those resulting from the combination of environmental exposures with social determinants and behaviors, are still unknown. This study evaluated the main effect of maternal environmental tobacco smoke (ETS), and its interaction with social-demographics and environmental factors on CHDs in China. A population-based, matched case-control study of 9452 live-born infants and stillborn fetuses was conducted using the Guangdong Registry of Congenital Heart Disease data (2004–2014). The CHDs were evaluated by obstetrician, pediatrician, or cardiologist, and confirmed by cardia tomography/catheterization. Controls were randomly chosen from singleton newborns without any malformation, born in the same hospital as the cases and 1:1 matched by infant sex, time of conception, and parental residence (same city and town to ensure sufficient geographical distribution for analyses). Face-to-face interviews were conducted to collect information on demographics, behavior patterns, maternal disease/medication, and environmental exposures. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals of ETS exposure on CHDs while controlling for all risk factors. Interactive effects were evaluated using a multivariate delta method for maternal demographics, behavior, and environmental exposures on the ETS-CHD relationship. Mothers exposed to ETS during the first trimester of pregnancy were more likely to have infants with CHD than mothers who did not (aOR = 1.44, 95% CI 1.25–1.66). We also observed a significant dose-response relationship when mothers were exposed to ETS and an increasing number of risk factors and CHDs. There were greater than additive interactions for maternal ETS and migrant status, low household income and paternal alcohol consumption on CHDs. Maternal low education also modified the ETS-CHD association on the multiplicative scale. These findings may help to identify high-risk populations for CHD, providing an opportunity for targeted preventive interventions.

Air pollution, being especially severe in the fast-growing developing world, continues to post a threat to public health. Yet, few studies are capable of quantifying well how different groups of people in different places experience different levels of air pollution at the global scale. In this paper, we use worldwide Chinese as a lens to quantify the spatiotemporal variations and geographic differences in PM2.5 exposures using unprecedented mobile phone big data and air pollution records. The results show that Chinese in South and East Asia suffer relatively serious PM2.5 exposures, where the Chinese in China have the highest PM2.5 exposures (52.8 μg/m3/year), which is fourfold higher than the exposures in the United States (10.7 μg/m3/year). Overall, the Chinese in Asian cities (35.5 μg/m3/year) experienced the most serious PM2.5 exposures when compared with the Chinese in the cities of other continents. These results, partly presented as a spatiotemporally explicit map of PM2.5 exposures for worldwide Chinese, help researchers and governments to consider how to address the effects of air pollution on public health with respect to different population groups and geographic locations.