Environmental Science and Pollution Research

Short-term stability assessment for the analysis of emerging contaminants in seawater Abstract This paper describes the stability study performed in seawater and seawater extracts (spiked at ~ 200 ng/L) for 23 emerging contaminants. Four different alternatives were tested at six different times (0, 3, 10, 17, 24 and 31 days): (i) seawater at 4 °C, (ii) mixed-mode solid-phase extraction cartridge (Bond Elute Plexa and Strata X-AW) stored at − 20 °C, (iii) polyethersulfone hollow fibre stored at − 20 °C and (iv) methanol extracts once the samples were extracted from PES hollow fibre and stored at − 20 °C. Moreover, the integrity of the supporting polymeric phases was studied by Raman, optical microscopy, differential scanning calorimetric and thermogravimetric analysis. As may be expected, seawater samples showed the lowest stability (losses between 21 and 99%) while methanol extract provides stable results (losses < 30%) over the tested period. In the case of solid-phase cartridges, the stability profile showed an average loss of 7% while, in polyethersulfone hollow fibres, losses up to 58% were observed. Finally, we were able to relate the lower efficiency of polyethersulfone fibres with the wettability of this material based on the thermogravimetric analysis.

Aerobic cometabolism of tetrabromobisphenol A by marine bacterial consortia Abstract The coastal environments worldwide are subjected to increasing TBBPA contamination, but current knowledge on aerobic biodegradability of this compound by marine microbes is lacking. The aerobic removal of TBBPA using marine consortia under eight different cometabolic conditions was investigated here. Results showed that the composition and diversity of the TBBPA-degrading consortia had diverged after 120-day incubation. Pseudoalteromonas, Alteromonas, Glaciecola, Thalassomonas, and Limnobacter were the dominant genera in enrichment cultures. Furthermore, a combination of beef extract- and peptone-enriched marine consortia exhibited higher TBBPA removal efficiency (approximately 60%) than the other substrate amendments. Additionally, Alteromonas macleodii strain GCW was isolated from a culture of TBBPA-degrading consortium. This strain exhibited about 90% of degradation efficiency toward TBBPA (10 mg L−1) after 10 days of incubation under aerobic cometabolic conditions. The intermediates in the degradation of TBBPA by A. macleodii strain GCW were analyzed and the degradation pathways were proposed, involving β-scission, debromination, and nitration routes.

Establishment of suitable separation distance by using different methods for malodor mitigation from palm oil mill Abstract Malaysia is the second-largest producer and exporter of palm oil amounting to 39% of world palm oil production and 44% of world exports (MPOB, 2014). An enormous amount of palm oil mill effluent is released during palm oil milling, and the effluent causes a major odor problem. Many methods, such as biofiltering, can be adopted to manage the malodor. However, these methods are expensive and require high maintenance. The separation distance method can be used as an alternative due to its low cost and effectiveness. This research was conducted to verify the performance of three different methods, namely, in-field monitoring by using an olfactometer, CALPUFF model, and Gaussian plume model. Given that no research has compared the three methods, this study examined the effectiveness of the methods and determined which among them is suitable for use in Malaysia. The appropriate separation distances were 1.3 km for in-field monitoring, 1.2 km for the CALPUFF model, and 0.5 for the Gaussian plume model. These different values of separation distance were due to the various approaches involved in each method. This research determined an appropriate means to establish a proper separation distance for reducing odor nuisance in areas around palm oil mills.

Sorption of iodine in soils: insight from selective sequential extractions and X-ray absorption spectroscopy Abstract The environmental fate of iodine is of general geochemical interest as well as of substantial concern in the context of nuclear waste repositories and reprocessing plants. Soils, and in particular soil organic matter (SOM), are known to play a major role in retaining and storing iodine. Therefore, we investigated iodide and iodate sorption by four different reference soils for contact times up to 30 days. Selective sequential extractions and X-ray absorption spectroscopy (XAS) were used to characterize binding behavior to different soil components, and the oxidation state and local structure of iodine. For iodide, sorption was fast with 73 to 96% being sorbed within the first 24 h, whereas iodate sorption increased from 11–41% to 62–85% after 30 days. The organic fraction contained most of the adsorbed iodide and iodate. XAS revealed a rapid change of iodide into organically bound iodine when exposed to soil, while iodate did not change its speciation. Migration behavior of both iodine species has to be considered as iodide appears to be the less mobile species due to fast binding to SOM, but with the potential risk of mobilization when oxidized to iodate.

Associations of gestational and the first year of life exposure to ambient air pollution with childhood eczema in Hubei, China Abstract Whether exposure to air pollution is associated with the increased incidence of childhood eczema is controversial. Only a few previous researches about the relationship between gestational and early-life exposures to ambient air pollutants and childhood eczema were conducted in China, and there is a lack of studies in Hubei province. This study aimed to explore the associations between air pollution exposure in gestation and the first year of life and childhood eczema. From November to December 2017, a total of 3383 children aged 3–6 years were recruited from 12 kindergartens in Hubei, China; 3167 were included in the final analysis. Parent-reported data involved with childhood eczema was inquired by questionnaire, and the concentrations of NO2, PM2.5, and PM10 were acquired from air quality monitoring stations which were the nearest to the twelve kindergartens. A binary logistic regression model was used to evaluate the associations of period-mean concentrations of individual pollutant exposure with childhood eczema. Of the 3167 children, 848 (26.8%) had a history of doctor-diagnosed eczema. After adjusting for the covariates, high levels of NO2, PM2.5, and PM10 exposures were significantly associated with a positive increase in risk of childhood eczema during the gestational period and the first year of life. In the gestational period, the estimate OR in the 3rd and 4th quartiles of NO2 was 1.256 and 1.496, respectively. During the first year of life, the estimate OR in the 3rd and 4th quartiles of NO2was 1.371 and 1.335, respectively. Our study indicated that the gestational period and the first year of life exposures to high levels of ambient NO2, PM2.5, and PM10 were significantly associated with increased eczema among preschool children. Some effective measures of prevention and intervention could be developed for preschool children.

Nitrogen pollution and sources in an aquatic system at an agricultural coastal area of Eastern China based on a dual-isotope approach Abstract Nitrogen (N) pollution of water courses is a major concern in most coastal watersheds in eastern China with intensive agricultural production. We use hydrogeological and dual-isotopic approaches to analyze the N concentrations, pollution, transformations, and sources of surface water and groundwater in an agricultural watershed of the Jiaozhou Bay (JZB) area. Results showed that dissolved total N (DTN) concentrations in sub-rivers (SRs) ranged from 6.0 to 25.3 mg N L−1 in the dry season and 9.1–26.7 mg N L−1 in the wet season, which indicated a positive relationship with the percentages of agricultural land. Meanwhile, the dominant dissolved N species in SRs changed from nitrate (NO3−, 64–100%) to dissolved organic N (DON, 52–77%) from the dry season to the wet season and the increased DON concentrations showed a positive relationship with the planted proportions of vegetable production systems. The NO3− concentrations of groundwaters ranged from 10.6 to 121.4 mg N L−1, which were over the limit for drinking water by the World Health Organization. Isotopic analysis indicated that most NO3− originated from the microbiological conversion via nitrification, whereas the deletion of denitrification was insignificant in this area. The results of the stable isotope analysis in R mixing model showed the contributions of potential NO3− sources which were in order of manure fertilizers (20.6–69.0%) > soil organic matter (19.5–53.2%) > chemical fertilizers (5.5–34.3%) > atmospheric deposition (1.3–18.8%). This study suggests that the management of crop productions and reasonable manure fertilizer application should be implemented to protect the quality of aquatic systems in the JZB area.

Abundance and properties of microplastics found in commercial fish meal and cultured common carp ( Cyprinus carpio ) Abstract Microplastics (MPs) are environmental contaminants that are of increasing global concern. This study investigated the presence of MPs in four varieties of marine-derived commercial fish meal, followed by identification of their polymer composition using Fourier transform infrared (FTIR) spectroscopy. Exposure experiments were conducted on cultured common carp (Cyprinus carpio) by feeding four varieties of commercially available fish meal to determine relationships between abundance and properties of MPs found both in meal and in those transferred to cultured common carp. Mean particle sizes were 452 ± 161 μm (± SD). Fragments were the predominant shape of MP found in fish meal (67%) and C. carpio gastrointestinal tract and gills (65%), and polypropylene and polystyrene were the most present plastic polymers found in fish meal (45% and 24%, respectively) and C. carpio (37% and 33%, respectively). Positive relationships were found between MP levels in fish meal and C. carpio. This study highlights that marine-derived fish meal may be a source of MPs which can be transferred to cultured fish, thus posing a concern for aquaculture.

Fungi-assisted phytoextraction of lead: tolerance, plant growth–promoting activities and phytoavailability Abstract Lead (Pb) is known for its low mobility and persistence in soils. The main aim of the present study was to explore potential of different fungal strains to promote phytoextraction of Pb-contaminated soils. Five non-pathogenic fungal strains (Trichoderma harzianum, Penicillium simplicissimum, Aspergillus flavus, Aspergillus niger, and Mucor spp.) were tested for their ability to modify soil properties (pH and organic matter) and to increase Pb phytoavailability at varying concentrations. Lead tolerance of fungal strains followed the decreasing order as A. niger > T. harzianum > A. flavus > Mucor sp. > P. simplicissimum. Lead solubility induced by A. flavus and Mucor spp. was increased by 1.6- and 1.8-fold, respectively, as compared to the control soil (Pb added, without fungi). A. flavus and Mucor spp. lowered the soil pH by − 0.14 and − 0.13 units, in soils spiked with 2000 mg Pb kg−1. The maximum increase in the percentage of organic matter (OM) recorded was 1.7-fold for A. flavus at 500 mg Pb kg−1 soil. Plant growth–promoting assays confirmed the beneficial role of these fungal strains. Significantly high production of IAA (249 μg mL−1) and siderophores (61%) was observed with A. niger, and phosphate solubilization with P. simplicissimum (58 μg mL−1). Based on the results in Pb-contaminated soils, Pelargonium hortorum L. inoculated with Mucor spp. showed the potential to enhance phytoextraction of Pb by promoting Pb phytoavailability in soil and improving plant biomass production through plant growth–promoting activities.

Prevalence of mycotoxins in feed and feed ingredients between 2015 and 2017 in Taiwan Abstract Contamination of feed by mycotoxins is a global epidemic that has a sizeable impact on animal health and causes economic losses. Mycotoxins, including aflatoxins (AFs), zearalenone (ZEN), fumonisins (FUMs), deoxynivalenol (DON), and ochratoxin A (OTA), lead to acute and chronic adverse effects in pigs. Animal feed and feed ingredients are commonly contaminated by one or more mycotoxins worldwide; however, the prevalence of mycotoxin contamination in feed and feed ingredients in Taiwan remains unclear. A total of 820 cornmeal and corn-based swine feed (pregnancy and nursery diets) samples provided by feed and animal producers were analyzed using the enzyme-linked immunosorbent assay method between January 2015 and December 2017 to determine the presence of mycotoxins. The results revealed that the most prevalent mycotoxin in Taiwan was DON, with 91.4% of positive samples between 2015 and 2017, followed by ZEN, AFs, and FUMs, with 70.2%, 58.0%, and 50.4% of positive samples, respectively. A similar prevalence of mycotoxins was observed in cornmeal and corn-based swine feed. Furthermore, 7.7% of the analyzed feed samples contained one mycotoxin, and 91.3% contained multiple mycotoxins. DON was the most prevalent mycotoxin in cornmeal and corn-based swine feed in Taiwan. Moreover, a high incidence of contamination by multiple mycotoxins was observed in swine feed. Awareness of mycotoxin presence in feed and development of mycotoxin detoxification strategies are unmet needs.

Growth of Dehalococcoides spp. and increased abundance of reductive dehalogenase genes in anaerobic PCB-contaminated sediment microcosms Abstract Polychlorinated biphenyls (PCBs) contaminate 19% of US Superfund sites and represent a serious risk to human and environmental health. One promising strategy to remediate PCB-contaminated sediments utilizes organohalide-respiring bacteria (OHRB) that dechlorinate PCBs. However, functional genes that act as biomarkers for PCB dechlorination processes (i.e., reductive dehalogenase genes) are poorly understood. Here, we developed anaerobic sediment microcosms that harbor an OHRB community dominated by the genus Dehalococcoides. During the 430-day microcosm incubation, Dehalococcoides 16S rRNA sequences increased two orders of magnitude to 107 copies/g of sediment, and at the same time, PCB118 decreased by as much as 70%. In addition, the OHRB community dechlorinated a range of penta- and tetra-chlorinated PCB congeners including PCBs 66, 70 + 74 + 76, 95, 90 + 101, and PCB110 without exogenous electron donor. We quantified candidate reductive dehalogenase (RDase) genes over a 430-day incubation period and found rd14, a reductive dehalogenase that belongs to Dehalococcoides mccartyi strain CG5, was enriched to 107 copies/g of sediment. At the same time, pcbA5 was enriched to only 105 copies/g of sediment. A survey for additional RDase genes revealed sequences similar to strain CG5’s rd4 and rd8. In addition to demonstrating the PCB dechlorination potential of native microbial communities in contaminated freshwater sediments, our results suggest candidate functional genes with previously unexplored potential could serve as biomarkers of PCB dechlorination processes.