Heavy metal contamination in the Bohai Sea (China) has been the focus of many studies, but most of them only focused on local pollution levels and thus lacked high spatial resolution for the whole sea. In this study, heavy metals (i.e., As, Cr, Cu, Cd, Pb, Zn, and Fe) in surface sediments were analyzed to assess the spatio-temporal pollution conditions of the Bohai Sea, an important coastal environment consisting of Bohai Bay, Laizhou Bay, and Liaodong Bay. The results indicated that the heavy metal concentration in the sediments was in the range of 6.43–32.18 mg/kg for As, 14.90–58.07 mg/kg for Cr, 3.90–27.19 mg/kg for Cu, 0.04–0.27 mg/kg for Cd, 11.09–30.95 mg/kg for Pb, 18.76–65.58 mg/kg for Zn, and 0.78%–2.55% for Fe. The distribution of heavy metals revealed that the concentrations were relatively low in Laizhou Bay, very high in the northwest coastal region of the Bohai Sea, and decreased from near-shore to off-shore areas. Moreover, both the enrichment factor and geo-accumulation index demonstrated that there was no contamination to be found for Cr, Cu, Zn in the region and a slight to moderate pollution of As, Cd, and Pb. Cd and As presented considerable potential ecological risk as a result of their high toxicity. The potential ecological risk index (RI) suggested that a third of the areas (northwest coastal area of the Bohai Sea) has moderate ecological risk. The risk area was generally decreased as offshore distance increased, which suggested that the contamination and risk of heavy metals are influenced by anthropogenic activities.

The ecotoxicology of surfactants is attracting wide attention due to the rapidly expanding global application. As interspecific relationships play one of the central roles in structuring biological communities, it is necessary to take it into risk assessments on surfactants. With this aim, our study investigated the interference of three common surfactants on the inducible defense of a freshwater phytoplankton Scenedesmus obliquus. Nonlethal environmentally relevant concentrations (10 and 100 μg L⁻¹) of several surfactants were set up. Results showed that growth and photosynthetic efficiency of Scenedesmus were inhibited during first 96 h, but recovered in the later stage. Surfactants interfered inducible defense of Scenedesmus against Daphnia grazing, and the interference was related to chemical characteristics of surfactants. The anionic surfactant sodium dodecyl sulfate (SDS) enhanced the colony formation even without grazing cues, whereas fewer defensive colonies were formed under the effects of cationic surfactant benzalkonium bromide (BZK) and nonionic surfactant polyoxyethylene (40) nonylphenol ether (NPE). These findings highlighted the sensitivity of grazer-induced morphological defense of Scenedesmus to surfactants even at nonlethal concentrations, which potentially affects the energy and information flow between trophic levels. This study appeals for more attention to take interspecific relationships into consideration in assessing the potential ecological risk of pollutants.

Wastewater has become one of the most important and least expensive water for the agriculture sector, as well as an alternative to the overexploitation of water resources. However, inappropriate treatment before its reuse can result in a negative impact on the environment, such as the presence of pathogens. This poses an increased risk for environmental safety, which can subsequently lead to an increased risk for human health. Among all the emerging wastewater pathogens, bacteria of the genus Helicobacter are some of the most disturbing ones, since they are directly related to gastric illness and hepatobiliary and gastric cancer. Therefore, the aim of this study was to determine the presence of potentially pathogenic Helicobacter spp. in treated wastewater intended for irrigation. We used a next generation sequencing approach, based on Illumina sequencing in combination with culture and other molecular techniques (qPCR, FISH and DVC-FISH), to analyze 16 wastewater samples, with and without an enrichment step. By culture, one of the direct samples was positive for H. pylori. FISH and DVC-FISH techniques allowed for detecting viable Helicobacter spp., including H. pylori, in seven out of eight samples of wastewater from the tertiary effluents, while qPCR analysis yielded only three positive results. When wastewater microbiome was analyzed, Helicobacter genus was detected in 7 samples. The different molecular techniques used in the present study provided evidence, for the first time, of the presence of species belonging to the genus Helicobacter such as H. pylori, H. hepaticus, H. pullorum and H. suis in wastewater samples, even after disinfection treatment.

The extensive use of melamine and its three derivatives (i.e., ammeline, ammelide, and cyanuric acid) resulted in their widespread occurrence in the environment. Nevertheless, limited information is available on their distribution in the aquatic environment. In this study, concentrations and profiles of melamine and its derivatives were determined in 223 water samples, comprising river water, lake water, seawater, tap water, bottled water, rain water, wastewater, and swimming pool water, collected from New York State, USA. The sum concentrations of melamine and its derivatives (∑₄MELs) decreased in the following order: swimming pool water (median: 1.5 × 10⁷ ng/L) ≫ wastewater (1240) > precipitation (739) > tap water (512) > river water (370) > lake water (347) > seawater (186) > bottled water (98). Cyanuric acid was the major compound, accounting for 60–100% of ∑₄MELs concentrations in swimming pool water, wastewater, precipitation, tap water, seawater, and bottled water, whereas melamine dominated in river and lake water (54–64% of ∑₄MELs). Significant positive correlations (0.499 < R < 0.703, p < 0.002) were found between the concentrations of melamine and atrazine (a triazine herbicide) in surface waters. The geographic distribution in the concentrations of ∑₄MELs in river, lake, and tap water corresponded with the degree of urbanization, suggesting that human activities contribute to the sources melamine and cyanuric acid in the aquatic environments. A preliminary hazard assessment of melamine and cyanuric acid in waters suggested that their ecological or human health risks were minimal. This is the first study to document the occurrence and spatial distribution of melamine and its derivatives in waters from the United States.

Recently, environmental risk and toxicity of neonicotinoid insecticides to honey bees have attracted extensive attention. However, toxicological understanding of neonicotinoid insecticides on gut microbiota is limited. In the present study, honey bees (Apis mellifera L.) were exposed to a series of nitenpyram for 14 days. Results indicated that nitenpyram exposure decreased the survival and food consumption of honey bees. Furthermore, 16S rRNA gene sequencing revealed that nitenpyram caused significant alterations in the relative abundance of several key gut microbiotas, which contribute to metabolic homeostasis and immunity. Using high-throughput RNA-Seq transcriptomic analysis, we identified a total of 526 differentially expressed genes (DEGs) that were significantly altered between nitenpyram-treated and control honey bee gut, including several genes related to metabolic, detoxification and immunity. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed nitenpyram affected several biological processes, of which most were related to metabolism. Collectively, our study demonstrates that the dysbiosis of gut microbiota in honey bee caused by nitenpyram may influence metabolic homeostasis and immunity of bees, and further decrease food consumption and survival of bees.

As emerging pollutants, the occurrence and risks of organophosphate esters (OPEs) in mariculture farms should be concerned; however, information is limited. Beibu Gulf is one of the essential mariculture zones in China. This study aimed to investigate the occurrence of OPEs in mariculture farms of the Beibu Gulf, their phase distribution and bioaccumulation among sediment, organisms (shrimp, crab, and oyster), water, and feed. Human exposure to OPEs through seafood consumption was also assessed. The total concentrations of the 11 target OPEs (∑₁₁OPEs) in the water samples ranged 32.9–227 ng L⁻¹. It was significantly higher in water from the culture ponds (mean 122 ng L⁻¹) than in water from the estuaries and nearshore areas (mean 51.1 ng L⁻¹) (nonparametric test, p < 0.05). ∑₁₁OPEs in the feeds averaged 46.0 (range 21.7–84.5) ng g⁻¹ dw, which is similar to the level in the organism samples (mean 55.5, range 21.3–138 ng g⁻¹ dw) and 4.4 times higher than that in the sediment (mean 10.9, range 35–22.1 ng g⁻¹ dw). The ∑₁₁OPEs released from the feeds to the culture ponds was estimated to be 49 μg m⁻² per three-month period. In the aquaculture ponds, the sediment-water distribution coefficient (log KOC), and the bioaccumulation factors from the water (log BWAFs) or the feed (log BFAFs) to the organisms, depend linearly on the hydrophobicity (log KOW) of OPEs. The log BWAFs and log BFAFs increased with increasing log KOW within the log KOW range of 1–7. The human exposure to OPEs through consumption of shrimp, crab, and oysters from the mariculture farms does not pose a health risk at present.

Whether toxicity of silver nanoparticles (AgNPs) to organisms originates from the nanoparticles themselves or from the dissolved Ag-ions is still debated, with the majority of studies claiming that extracellular release of Ag-ions is the main cause of toxicity. The objective of this study was to determine the contributions of both particles and dissolved ions to toxic responses, and to better understand the underlying mechanisms of toxicity. In addition, the pathways of AgNPs exposure to plants might play an important role and therefore are explicitly studied as well. We systematically assessed the phytotoxicity, internalization, biodistribution, and antioxidant responses in lettuce (Lactuca sativa) following root or foliar exposure to AgNPs and ionic Ag at various concentrations. For each endpoint the relative contribution of the particle-specific versus the ionic form was quantified. The results reveal particle-specific toxicity and uptake of AgNPs in lettuce as the relative contribution of particulate Ag accounted for more than 65% to the overall toxicity and the Ag accumulation in whole plant tissues. In addition, particle toxicity is shown to originate from the accumulation of Ag in plants by blocking nutrient transport, while ion toxicity is likely due to the induction of excess ROS production. Root exposure induced higher toxicity than foliar exposure at comparable exposure levels. Ag was found to be taken up and subsequently translocated from the exposed parts of plants to other portions regardless of the exposure pathway. These findings suggest particle related toxicity, and demonstrate that the accumulation and translocation of silver nanoparticles need to be considered in assessment of environmental risks and of food safety following consumption of plants exposed to AgNPs by humans.

Both air pollution and dyslipidemias contributed to large number of deaths and disability-adjusted life lost years. Long-term air pollution exposure was related to changed blood lipids and risk of dyslipidemias. This study was designed to evaluate relationships between air pollutants, blood lipids and prevalence of dyslipidemias in a Chinese rural population exposed to high-level air pollution based on baseline data of The Henan Rural Cohort study. An amount of 39,057 participants from rural areas in China were included. The 3-year average exposure of air pollutants (PM2.5, PM10, NO2) was estimated by a spatiotemporal model. Logistic and linear regression models were employed to explore relationships between air pollutants, blood lipids (TC, TG, HDL-C and LDL-C) and prevalence of dyslipidemias. The three-year concentration of PM2.5, PM10 and NO2 was 72.8 ± 2.3 μg/m3, 131.5 ± 5.7 μg/m3and 39.1 ± 3.1 μg/m3, respectively. Overall, increased air pollution exposure was related to increased TC and LDL-C, while decreased TG and HDL-C. Each 1-μg/m3 increment of PM2.5 was related to 0.10% (0.07%–0.19%) increase in TC, 0.63% (0.50%–0.77%) increase in LDL-C, 2.93% (2.70%–3.16%) decrease in TG, 0.49% (0.38%–0.60%) decrease in HDL-C; and 5.7% (95%CI: 3.7%–7.6%), 4.0% (95%CI: 2.1%–6.0%) and 3.8% (95%CI: 2.5%–5.1%) increase in odds for hypercholesterolemia, hyperbetalipoproteinemia and hypoalphalipoproteinemia, respectively. Stronger associations were found in male and older participants. Findings suggest that air pollutants were associated with changed blood lipid levels and higher risk of dyslipidemias among rural population. Male and elder people should pay more attention to personal safety protection.