Determination of per- and polyfluoroalkyl compounds in paper recycling grades using ultra-high-performance liquid chromatography-high-resolution mass spectrometry.

Globally, per- and polyfluoroalkyl substances (PFAS)-related research on paper products has focused on food packaging with less consideration on the presence of PFAS at different stages of the paper recycling chain. This study analysed the prevalence of PFAS in paper grades used for the manufacture of recycled paperboard. The presence of PFAS was attributed to the use of PFAS-containing additives, consumer usage, exposure to packed goods as well as contamination during mingling, sorting, collection, and recovery of paper recycling material. Q Orbitrap mass spectrometry was used to analyse the paper samples after accelerated solvent extraction and solid phase extraction. The distribution and possible propagation of 22 PFAS were determined in pre-consumer, retail and post-consumer paper products. Post-consumer samples had the highest combined average concentration (ΣPFAS) at 213 ng/g, while the ΣPFAS in retail (159 ng/g) and pre-consumer samples (121 ng/g) was detected at lower concentrations. This study showed that waste collection and recycling protocols may influence PFAS propagation and that measures must be developed to minimise and possibly eliminate exposure opportunities.

Exposure levels and health implications of fungicides, neonicotinoid insecticides, triazine herbicides and their associated metabolites in pregnant women and men.

Exposure to pesticides can pose a series of advance effects on human health. However, the exposure levels and health implications of the current use pesticides and their metabolites in both men and pregnant women remain unclear. In this study, an analytical method was developed to quantify fungicides, neonicotinoid insecticides, triazine herbicides, and their metabolites in the human serum. Fifty of the 73 target pesticides and metabolites were detected in the human serum of men and pregnant women from Wuxi, China, which included 11 triazine herbicides and metabolites, 17 neonicotinoid insecticides and metabolites, and 22 fungicides. Fungicides had the highest cumulative concentration (49.5 ng/mL), followed by neonicotinoid insecticides and metabolites (6.38 ng/mL), and triazine herbicides and metabolites (5.10 ng/mL). Moreover, the estimated daily intake (EDI) of fungicides was 10.4 and 12.7 times higher than that of triazine herbicides (included their metabolites) and neonicotinoid insecticides (included their metabolites), respectively. Of the three categories of pesticides, exposure to fungicides contributed to the highest exposure risk within the hazard quotient in the range of 5.1 × 10-3-0.17. Correlation analysis revealed that the pesticide exposure levels in human serum were correlated with their maximum residue levels in vegetables and fruits. Pesticide exposure has also been correlated with the weight and Body Mass Index (BMI) of humans based on structural equation modeling. This study provides new insights into the exposure of men and pregnant women to a cocktail of fungicides, neonicotinoid insecticides, triazine herbicides and their metabolites.

Conflicts of Interest in the Assessment of Chemicals, Waste, and Pollution.

Pollution by chemicals and waste impacts human and ecosystem health on regional, national, and global scales, resulting, together with climate change and biodiversity loss, in a triple planetary crisis. Consequently, in 2022, countries agreed to establish an intergovernmental science-policy panel (SPP) on chemicals, waste, and pollution prevention, complementary to the existing intergovernmental science-policy bodies on climate change and biodiversity. To ensure the SPP's success, it is imperative to protect it from conflicts of interest (COI). Here, we (i) define and review the implications of COI, and its relevance for the management of chemicals, waste, and pollution; (ii) summarize established tactics to manufacture doubt in favor of vested interests, i.e., to counter scientific evidence and/or to promote misleading narratives favorable to financial interests; and (iii) illustrate these with selected examples. This analysis leads to a review of arguments for and against chemical industry representation in the SPP's work. We further (iv) rebut an assertion voiced by some that the chemical industry should be directly involved in the panel's work because it possesses data on chemicals essential for the panel's activities. Finally, (v) we present steps that should be taken to prevent the detrimental impacts of COI in the work of the SPP. In particular, we propose to include an independent auditor's role in the SPP to ensure that participation and processes follow clear COI rules. Among others, the auditor should evaluate the content of the assessments produced to ensure unbiased representation of information that underpins the SPP's activities.

Identification and Coexposure of Neonicotinoid Insecticides and Their Transformation Products in Retail Cowpea (Vigna unguiculata).

There is growing evidence that the transformation products of emerging contaminants in foodstuffs may pose a health risk to humans. However, the exact identities, levels, and estimated dietary intake (EDI) of neonicotinoid transformation products in crops remain poorly understood. We established an extended suspect screening strategy to investigate neonicotinoid insecticides and their transformation products in retail cowpea from 11 cities in Hainan Province, China. Forty-nine transformation products were identified in retail cowpea, of which 22-36 were found in 98.6% of the samples. Notably, 31 new transformation products were derived from new processes or a combination of different transformation processes. The mean concentrations of neonicotinoids and nine of the transformation products (with authentic standards) were in the ranges of 0.0824-5.34 and 0.0636-1.50 ng/g, respectively. The cumulative EDIs of the quantified transformation products were lower than those of parent neonicotinoids with the exception of clothianidin desmethyl, which had a ratio of 1157%. However, the coexistence of the other 40 transformation products (without authentic standards) in cowpea suggested that the exposure risk from all of the transformation products might be higher. This study demonstrated that pesticide transformation products should be considered in food chain risk assessments and included in future regulatory management.

Vertical changes in water depth and environmental variables drove the antibiotics and antibiotic resistomes distribution, and microbial food web structures in the estuary and marine ecosystems.

The influence of vertical changes in water depth on emerging pollutants distribution and microbial food web remains elusive. We investigated the influence of vertical transition in water depth on the environmental variables, antibiotics and antibiotic resistomes, and microbial community structures in estuary and marine ecosystems (0-50 m). Stepwise multiple linear regression model showed that among investigated environmental variables, change in water salinity was the most influential factor dictating the fluoroquinolone and macrolides concentrations, while dissolved oxygen and turbidity were the key influencers of sulfonamides and beta-lactam concentrations, respectively. Bacterial and eukaryotic diversity and niche breadth significantly increased with the increasing water depth. Ecosystem food web structure at the bottom depths was more stable than at the middle and surface depths. At the surface depth, the top 5 keystone genera were Cryothecomonas, Syndiniales, Achromobacter, Pseudopirsonia, and Karlodinium. Whereas Eugregarinorida, Neptuniibacter, Mychonastes, Novel_Apicomplexa_Class_1, Aplanochytrium and Dietzia, Halodaphnea, Luminiphilus, Aplanochytrium, Maullinia dominated the top 5 genera at the middle and the bottom depth, respectively. Absolute abundance of antibiotic resistance genes (ARGs) was drastically increased at the surface depth compared with the middle and bottom depths. Abundance of the top 10 ARGs and mobile genetic elements (MGEs) detected including tnpA-05, aadA2-03, mexF, aadA1, intI-1(clinic), qacEdelta1-02, aadA-02, qacEdelta1-01, cmlA1-01, and aadA-01 were amplified at the surface depth. This study demonstrated that ARGs abundance was disproportionate to bacterial diversity, and anthropogenic disturbances, confinement, MGEs, and ecosystem stability play primary roles in the fate of ARGs. The findings of this study also implicate that vertical changes in the water depth on environmental conditions can influence antibiotic concentrations and microbial community dramatically.

Identification, occurrence, concentration and composition profile of fiproles in municipal wastewater treatment plants.

Although fipronil and several of its transformation products are ubiquitous in aquatic environments, limited information is available on the structural identities, detection frequencies, concentrations and composition profiles of fiproles (fipronil and its known and unknown transformation products) in municipal wastewater treatment plants (WWTPs). In this study, a suspect screening analysis was applied to identify and characterize fipronil transformation products in 16 municipal WWTPs from three cities in China. In addition to fipronil and its four transformation products (fipronil amide, fipronil sulfide, fipronil sulfone and desulfinyl fipronil), fipronil chloramine and fipronil sulfone chloramine were detected for the first time in municipal wastewater. Moreover, the cumulative concentrations of six transformation products were 0.236 ng/L and 3.44 ng/L in wastewater influents and effluents, and accounted for one-third (in influents) to half (in effluents) of fiproles. Of those transformation products, two chlorinated byproducts (fipronil chloramine and fipronil sulfone chloramine) were major transformation products in both municipal wastewater influents and effluents. Notably, the log Kow and bioconcentration factor (evaluated by EPI Suite software) of fipronil chloramine (log Kow = 6.64, and BCF = 11,200 L/kg wet-wt) and fipronil sulfone chloramine (log Kow = 4.42, and BCF = 382.9 L/kg wet-wt) were greater than that of their parent compound. Considering the persistence, bioaccumulation potential and toxicity, the high detection rates of fipronil chloramine and fipronil sulfone chloramine in urban aquatic systems need to be specifically considered in future ecological risk assessments.

Enhanced nutrient removal in agro-industrial wastes-amended hybrid floating treatment wetlands treating real sewage: Laboratory microcosms to field-scale studies.

The use of natural agro-industrial materials as suspended fillers (SFs) in floating treatment wetlands (FTWs) to enhance nutrient removal performance has recently been gaining significant attention. However, the knowledge concerning the nutrient removal performance enhancement by different SFs (alone and in mixtures) and the major removal pathways is so far inadequate. The current research, for the first time, carried out a critical analysis using five different natural agro-industrial materials (biochar, zeolite, alum sludge, woodchip, flexible solid packing) as SFs in various FTWs of 20 L microcosm tanks, 450 L outdoor mesocosms, and a field-scale urban pond treating real wastewater over 180 d. The findings demonstrated that the incorporation of SFs in FTWs enhanced the removal performance of total nitrogen (TN) by 20-57% and total phosphorus (TP) by 23-63%. SFs further enhanced macrophyte growth and biomass production, leading to considerable increases in nutrient standing stocks. Although all the hybrid FTWs showed acceptable treatment performances, FTWs set up with mixtures of all five SFs significantly enhanced biofilm formation and enriched the abundances of the microbial community related to nitrification and denitrification processes, supporting the detected excellent N retention. N mass balance assessment demonstrated that nitrification-denitrification was the major N removal pathway in reinforced FTWs, and the high removal efficiency of TP was attributable to the incorporation of SFs into the FTWs. Nutrient removal efficiencies ranked in the following order among the various trials: microcosm scale (TN: 99.3% and TP: 98.4%) > mesocosm scale (TN: 84.0% and TP: 95.0%) > field scale (TN: -15.0-73.7% and TP: -31.5-77.1%). These findings demonstrate that hybrid FTWs could be easily scaled up for the removal of pollutants from eutrophic freshwater systems over the medium term in an environmentally-friendly way in regions with similar environmental conditions. Moreover, it demonstrates hybrid FTW as a novel way of disposing of significant quantities of wastes, showing a win-win means with a huge potential for large-scale application.

Trophic transfer of polycyclic aromatic hydrocarbons in marine mammals based on isotopic determination.

The tissue distribution (liver, kidney, heart, lung, and muscle), source, and trophic transfer of 15 polycyclic aromatic hydrocarbons (PAHs) were studied on 14 stranded East Asian finless porpoises (Neophocaena asiaeorientalis sunameri), 14 spotted seals (Phoca largha), and 9 stranded minke whales (Balaenoptera acutorostrata) from Yellow Sea and Liaodong Bay. The PAHs levels ranged from below the limit of detection to 459.22 ng g-1 dry weight in the tissues of the three marine mammals, and light molecular weight PAHs were the primary pollutants. Although the PAHs levels were relatively higher in internal organs of the three marine mammals, generally no tissue-specific distribution of the PAHs congeners was found, either for gender-specific distribution of PAHs in the East Asian finless porpoises. However, species specific PAHs concentration distribution were obtained. The PAHs were mainly originated from petroleum and biomass combustion in the East Asian finless porpoises, while those for the spotted seals and minke whales were complex. Trophic level associated biomagnification was found for phenanthrene, fluoranthene, and pyrene in the minke whale. Benzo(b)fluoranthene exhibited a significant biodilution with increasing trophic levels in the spotted seals, but the total concentration of the PAHs showed a significant biomagnification with increasing trophic levels. Trophic level-associated biomagnification of acenaphthene, phenanthrene, anthracene, and ∑PAHs were found in the East Asian finless porpoise, while pyrene exhibited obvious biodilution with increasing trophic levels. Our current study filled knowledge gaps on tissue distribution and trophic transfer of the PAHs in the investigated three marine mammals.

Golgi fucosyltransferase 1 reveals its important role in α-1,4-fucose modification of N-glycan in CRISPR/Cas9 diatom Phaeodactylum tricornutum.

Phaeodactylum tricornutum (Pt) is a critical microbial cell factory to produce a wide spectrum of marketable products including recombinant biopharmaceutical N-glycoproteins. N-glycosylation modification of proteins is important for their activity, stability, and half-life, especially some special modifications, such as fucose-modification by fucosyltransferase (FucT). Three PtFucTs were annotated in the genome of P. tricornutum, PtFucT1 was located on the medial/trans-Golgi apparatus and PtFucT2-3 in the plastid stroma. Algal growth, biomass and photosynthesis efficiency were significantly inhibited in a knockout mutant of PtFucT1 (PtFucT1-KO). PtFucT1 played a role in non-core fucose modification of N-glycans. The knockout of PtFucT1 might affect the activity of PtGnTI in the complex and change the complex N-glycan to mannose type N-glycan. The study provided critical information for understanding the mechanism of protein N-glycosylation modification and using microalgae as an alternative ecofriendly cell factory to produce biopharmaceuticals.

Ecological mechanisms of sedimental microbial biodiversity shift and the role of antimicrobial resistance genes in modulating microbial turnover.

The mechanisms of phylogenetic turnover of microbial communities to environmental perturbations in sediments remain unclear. In this study, the molecular mechanisms of phylogenetic turnover, and impact of antibiotics and antibiotic resistance genes (ARGs) on the modification of microbial assemblages were unravelled. We investigated 306 ARGs, 8 transposases, and 4 integron integrases, bacteria, and eukaryotic diversity through high-throughput quantitative PCR and illumina sequencing, 21 antibiotics and 3 tetracycline byproducts. The freshwater and estuary ecosystems were mainly dominated by genus Sulfurovum and colonised by closely related species compared with the estuary (closeness centrality = 0.42 vs. 0.46), which was dominated by genus Mycobacterium. Eighty-six percent of the ecological process in the bacterial community was driven by stochastic processes, while the rest was driven by deterministic processes. Environmental-related concentrations of antibiotics (0.15-32.53 ng/g) stimulated the proliferation of ARGs which potentially modulated the microbial community assembly. ARG acquisition significantly (P < 0.001) increased eukaryotic diversity through protection mechanisms. ARGs showed complex interrelationships with the microbial communities, and phylum arthropods and Nematea demonstrated the strongest ARG acquisition potential. This study provides key insights for environmental policymakers into understanding the ecological impact of antibiotics and the role of ARGs in modulating the phylogenetic turnover of microbial communities and trophic transfer mechanisms.

Interspecies differences in mammalian susceptibility to legacy POPs and trace metals using skin fibroblast cells.

The susceptibility to trace metals and legacy POPs is different between terrestrial and marine mammals. In this study, we established the first cell line from Indo-Pacific finless porpoises and compared the cellular responses of skin fibroblast cells from Pygmy killer whales, Pantropic spotted dolphins, Indo-Pacific finless porpoises, mice, and humans following exposure to copper, methylmercury, cadmium, PCB126, PCB153, and BDE47 to better understand the interspecies sensitivities of mammals to chemical pollutants. We conducted a risk assessment by comparing no-observed effect concentrations (NOEC), lowest-observed effect concentrations (LOEC), and half maximal effective concentrations (EC50) from cell viability assays and previously reported pollutant body burdens in mammals. Based on the in vitro data, Indo-Pacific finless porpoises were more sensitive to copper and methylmercury than other mammals. PCB153 exposure reduced cell viability in all mammals except humans, while PCB126 was more potent, with 13.33 µg/mL exposure reducing cell viability in all mammals. In contrast, BDE47 exposure reduced cell viability only in terrestrial mammals in addition to pantropic spotted dolphin. Based on the in vitro data and the natural context of metal concentrations, both methylmercury and cadmium posed a higher risk to cetaceans than human, while copper posed a lower risk to cetaceans. All three legacy POPs (PCB126, PCB153, and BDE47) posed minor risk to cetaceans for short-term exposure. This study demonstrated that a species-specific in vitro model may provide more accurate information on the potential risk of pollutants to mammals. However, due to the bioamplification of POPs and their potential impact on the endocrine system and immune system of cetaceans, risk assessment with long-term exposure with more in vitro models should be further studied.

Tissue distribution and trophic magnification of trace elements in typical marine mammals in Bohai and north Yellow Seas.

A total of 20 stranded spotted seals (Phoca largha) and 9 stranded minke whales (Balaenoptera acutorostrata) were collected from Liaodong Bay and the northern part of the Yellow Sea to investigate the tissue distribution (liver, kidney, heart, lung, and muscle), risk, and trophic magnification of 13 trace elements (TEs, Hg, As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, Sn, V, Zn). The 13 TEs were all detected in all spotted seal and minke whale tissue samples, with mean concentrations ranging from 0.041 to 136.3 mg kg-1 dry weight (dw) and 0.022 to 152.6 mg kg-1 dw, respectively. Zn was the dominant contaminant in all tissues for both spotted seals and minke whales. There was tissue-specific distribution of TEs in both marine mammals, and the TEs tended to accumulate in internal organs. Significant positive correlations were found in the body length of the spotted seals and minke whales among some of the TEs, especially for Cd in the internal organs. Gender-dependent distribution of the TEs was not obtained for the spotted seal. Ecological risk evaluation for spotted seals and minke whales suggested that greater concern should be given to Hg, As, and Se. Based on the TE concentrations detected in this study and trophic levels determined by stable carbon and nitrogen isotopes, trophic level-associated biodilution was obtained for As, Cd, Co, Cu, Mn, Pb, Se, Sn, and V in the spotted seal, while Zn displayed a significant biomagnification trend with increasing trophic levels. In the case of the minke whale, As, Cd, Co, Mn, Pb, Se, and V displayed significant biomagnification trends with increasing trophic levels.

Rare earth elements in oysters and mussels collected from the Chinese coast: Bioaccumulation and human health risks.

Rare earth elements (REEs) are increasingly used in various industries worldwide, resulting in their release into aquatic ecosystems. We evaluated the distribution and bioaccumulation of 14 REEs in marine sediments and biotas along the Chinese coasts. The total concentration of REEs (ΣREEs) in sediments was 41.65-170.94 mg/kg. The concentrations of ΣREEs were 1.97-4.77 and 0.62-4.96 mg/kg dry mass (DM) for oysters and mussels. The concentration of total light REEs (ΣLREEs) was higher than the concentration of total heavy REEs (ΣHREEs) at all samples. The bioaccumulation factor (BAF) of ΣLREEs was higher than ΣHREEs and BAF of ΣREE was 0.34-1.49 and 0.25-1.10 for oysters and mussels. The positive correlation between sediments and biotas was higher in mussels than oysters, showing a good potential for being environmental indicators for REEs. The risk of REEs to humans via oysters and mussels consumption could be negligible based on the estimated daily intake.

Risk factors associated with a high incidence of sexually transmitted infections in Beitbridge, Zimbabwe.

BACKGROUND:  Sexually transmitted infections (STIs) are a major public health challenge, particularly in developing countries where the health infrastructure is often poor. Despite having a number of interventions in Beitbridge (such as the 24-h wellness centre), Zimbabwe, the incidence and prevalence of STIs is increasing. OBJECTIVES:  This study, therefore, aims to assess the risk factors associated with the high incidence of STIs in urban Beitbridge. METHOD:  A case-control study was conducted on 30 respondents who had suffered from STIs (selected from the registers at Beitbridge hospital and followed up) and 90 respondents who had not suffered from STIs (from the community) who resided in Beitbridge for at least 6 months and this excluded all those who were in transit. The factors contributing to the high incidence of STIs were identified using a pretested interviewer-administered semi-structured questionnaire in conjunction with a Likert scale to establish the attitudes and risk behaviours of the respondents on STIs. RESULTS:  A significant association was observed between high STI incidences and the nature of occupation (odds ration [OR]: 3.8), area of residence (OR: 2.78), number of sexual partners (OR: 7.56), payment demanded for sex (OR 22), condom use (OR: 3.7), alcohol use (OR: 2.86), and suspicion that partners had other sexual companions (OR: 15.5). Furthermore, a larger proportion of controls were knowledgeable on STIs as compared to the cases who participated in the study. CONCLUSION:  There is a need to develop awareness strategies that foster safe sexual practices, particularly among populations who do not choose abstinence or a single sexual partner lifestyle.

Spatial distribution and ecological risks of polychlorinated biphenyls in a river basin affected by traditional and emerging electronic waste recycling in South China.

With development of e-waste related legislation in China, formal recycling activities are designated in some areas while informal ones are illegally transferred to emerging areas to avoid supervision. However, the resulting environmental impact and ecological risks are not clear. Here, we investigated the discharge of polychlorinated biphenyls (PCBs) to soil and aquatic environments by e-waste recycling activities in the Lian River Basin, China. The study area included a designated industrial park in the traditional e-waste recycling area (Guiyu, known as the world's largest e-waste center), several emerging informal recycling zones, and their surrounding areas and coastal area. A total of 27 PCBs were analyzed, and the highest concentration was found in an emerging site for soil (354 ng g-1) and in a traditional site for sediment (1350 ng g--1) respectively. The pollution levels were significantly higher in both the traditional and emerging recycling areas than in their respective upstream countryside areas (p = 0.0356 and 0.0179, respectively). Source analysis revealed that the traditional and emerging areas had similar PCB sources mainly associated with three PCB technical mixtures manufactured in Japan (KC600) and the USA (Aroclor 1260 and Aroclor 1262). The PCB pollution in their downstream areas including the coastal area was evidently affected by the formal and informal recycling activities through river runoff. The ecological risk assessments showed that PCBs in soils and sediments in the Lian River Basin could cause adverse ecotoxicological consequences to humans and aquatic organisms.

Insights on Gut and Skin Wound Microbiome in Stranded Indo-Pacific Finless Porpoise (Neophocaena phocaenoides).

The gut microbiome is a unique marker for cetaceans' health status, and the microbiome composition of their skin wounds can indicate a potential infection from their habitat. Our study provides the first comparative analysis of the microbial communities from gut regions and skin wounds of an individual Indo-Pacific finless porpoise (Neophocaena phocaenoides). Microbial richness increased from the foregut to the hindgut with variation in the composition of microbes. Fusobacteria (67.51% ± 5.10%), Firmicutes (22.00% ± 2.60%), and Proteobacteria (10.47% ± 5.49%) were the dominant phyla in the gastrointestinal tract, while Proteobacteria (76.11% ± 0.54%), Firmicutes (22.00% ± 2.60%), and Bacteroidetes (10.13% ± 0.49%) were the dominant phyla in the skin wounds. The genera Photobacterium, Actinobacillus, Vibrio, Erysipelothrix, Tenacibaculum, and Psychrobacter, considered potential pathogens for mammals, were identified in the gut and skin wounds of the stranded Indo-Pacific finless porpoise. A comparison of the gut microbiome in the Indo-Pacific finless porpoise and other cetaceans revealed a possible species-specific gut microbiome in the Indo-Pacific finless porpoise. There was a significant difference between the skin wound microbiomes in terrestrial and marine mammals, probably due to habitat-specific differences. Our results show potential species specificity in the microbiome structure and a potential threat posed by environmental pathogens to cetaceans.

Performance of various fillers in ecological floating beds planted with Myriophyllum aquaticum treating municipal wastewater.

The performance of different suspended fillers (zeolite, drinking water treatment residual, biochar, woodchip and stereo-elastic packing) and their combinations in treating municipal wastewater in ecological floating beds (Eco-FBs) planted with Myriophyllum aquaticum was assessed. Six sets of enhanced Eco-FBs were developed to assess the individual and synergistic effects of combinations of the various fillers and microorganisms on nutrient elimination. The results demonstrated mean TN, NH4-N, TP and COD purification efficiencies of 99.2 ±â€¯11.2 %, 99.82 ±â€¯16.4 %, 98.3 ±â€¯14.3 %, and 96.1 ±â€¯12.3 %, respectively in the Eco-FBs strengthened with all five fillers. The corresponding purification rates were 0.89 ±â€¯0.14, 0.75 ±â€¯0.12, 0.08 ±â€¯0.016, and 7.05 ±â€¯1.09 g m-2 d-1, which were 2-3 times higher than those of the conventional Eco-FB system. High-throughput sequencing showed that some genera related to nutrient transformation, including Proteobacteria (24.13-51.95 %), followed by Chloroflexi (5.64-25.01 %), Planctomycetes (8.48-14.43 %) and Acidobacteria (2.29-11.65 %), were abundantly enriched in the strengthened Eco-FBs. Enhancement of the Eco-FBs with various fillers significantly increased microbial species richness and diversity as demonstrated by Chao1, Shannon and Simpson's indexes, particularly when all the five fillers were combined. Therefore, introducing suspended fillers into Eco-FBs is an appropriate approach for improving nutrient elimination from municipal wastewater.

Effects of norfloxacin, copper, and their interactions on microbial communities in estuarine sediment.

The discharge of antibiotics and metals in estuaries is of great concern since they threaten microbial communities that are critical for maintaining ecosystem function. To understand single and combined effects of norfloxacin (0-20 µg g-1) and copper (40 µg g-1) on microbial ecology in estuaries, we evaluated changes in bacteria population, inhibition rates, and microbial composition in estuarine sediments over a 28-day period. Bacteria population significantly decreased following single and combined exposure to norfloxacin and copper throughout the incubation period, except on Day 28 in treatments exposed to copper, 20 µg g-1 norfloxacin, or both. These three treatment groups had lower Shannon diversity and Simpson's indices on Day 28 than other treatments and the controls suggesting recovery in bacteria population did not correspond with recovery in richness and evenness. Furthermore, functional predictions revealed that the effect of time and contaminants were significantly different on some microbial community functions on Day 28, especially the combination of Cu and high concentration NFX, including aerobic chemoheterotrophy, methanol oxidation and methylotrophy. Thus, norfloxacin and copper had significant adverse effects on microbial communities in estuarine sediments; however, the combined effects were variable and depended on exposure duration and antibiotic concentration.

Accumulation of nutrients and potentially toxic elements in plants and fishes in restored mangrove ecosystems in South China.

Mangroves are highly dynamic ecosystems that offer important services such as maintaining biodiversity, filtering pollutants, and providing habitats for fishes. We investigated the uptake and accumulation of nutrients and potentially toxic elements in mangrove plants and fish to better understand the role of mangrove restoration in maintaining mangrove biota quality. In mangrove plants, the average bioconcentration factors of nutrients and potentially toxic elements were in the order P > Pb > Mn > Mg > Se > Zn > Hg > Cu > Cd > As > Co > Cr > Ni > Fe > V > Sb, where only P (all plant species) and Pb (Sonneratia apetala Buchanan-Hamilton) had a BCF > 1.0 in mangrove plants. In general, Sonneratia spp. had better performances than Kandelia candel (Linn.) Druce, Aegiceras corniculatum (Linn.) Blanco and Acanthus ilicifolius L. Sp. in terms of nutrient uptake and toxic metal(loid)s accumulation, and the best uptake capacity was found in S. apetala. Fast growth and easy adaptation make S. apetala suitable for a restored mangrove ecosystem, but continual management is needed to prevent its suppression of mangrove species diversity. The concentration of As, Cd, Hg, Cu, Cr and Pb in the mangrove sediment were 30-220% higher than the Chinese National Standard of Marine Sediment Quality Class I limits, suggesting that the sediments were unsuitable for aquaculture and nature reserves. Although a higher toxic metal(loid)s concentration in the sediment was found, the target hazard quotient (THQ) of this toxic metal(loid)s in 5 mangrove habitat fishes was <1.0, except THQ of Pb in Boleophthalmus pectinirostris Linnaeus was 1.17, and THQ of Cr in Bostrychus sinensis Lacépède was 1.12. The low THQ (less than 1.0) of mangrove habitat fishes suggested that the restored mangrove system could alleviate the bioaccumulation of toxic metal(loid)s in mangrove fish.

Biogeographic patterns of benthic microbial communities in metal(loid)-contaminated semi-enclosed bay.

Anthropogenic activities can adversely impact biogeochemical processes essential for maintaining ecosystem health in semi-enclosed bays. However, the influence of anthropogenic contaminants such as potentially toxic elements on microbial communities that regulate biogeochemical cycles in semi-enclosed bays is poorly understood. We determined the concentrations of four potentially toxic elements (Cu, Zn, Pb, and As) in sediments from a typical tropical semi-enclosed bay in Guangdong, China. Source apportionment using Pearson's correlation analysis revealed that aquaculture activities were probably the primary source of Cu, Zn, and Pb. Using high-throughput sediment DNA sequencing, we found that Proteobacteria was the dominant phylum in sediments. There was no evidence suggesting site-specific variation in microbial function even though sediments adjacent to aquaculture discharge points had higher microbial diversity. In contrast, pollutant-specific variations were observed; for example, Zn and Pd showed potential adverse effects on the environmental information processing function, while As showed a negative correlation with metabolic function. Based on different environmental characteristics, future research should consider the impact of multiple factors on the bacterial community in aquaculture systems.