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Critical review of soil contamination by polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs); concentrations, sources and congener profiles النص الكامل
2017
McGrath, Thomas J. | Ball, A. S. | Clarke, Bradley O.
Polybrominated diphenyl ethers (PBDEs) have been used in a broad array of polymeric materials such as plastics, foams, resins and adhesives to inhibit the spread of fires since the 1970s. The widespread environmental contamination and well documented toxic effects of PBDEs have led to bans and voluntary withdrawals in many jurisdictions. Replacement novel brominated flame retardants (NBFRs) have, however, exhibited many of the same toxic characteristics as PBDEs and appear to share similar environmental fate. This paper presents a critical review of the scientific literature regarding PBDE and NBFR contamination of surface soils internationally, with the secondary objective of identifying probable pollution sources. An evaluation of NBFR distribution in soil was also conducted to assess the suitability of the newer compounds as replacements for PBDEs, with respect to their land contamination potential. Principle production of PBDEs and NBFRs and their consequent use in secondary polymer manufacture appear to be processes with strong potential to contaminate surrounding soils. Evidence suggests that PBDEs and NBFRs are also released from flame retarded products during disposal via landfill, dumping, incineration and recycling. While the land application of sewage sludge represents another major pathway of soil contamination it is not considered in this review as it is extensively covered elsewhere. Both PBDEs and NBFRs were commonly detected at background locations including Antarctica and northern polar regions. PBDE congener profiles in soil were broadly representative of the major constituents in Penta-, Octa- and Deca-BDE commercial mixtures and related to predicted market place demand. BDE-209 dominated soil profiles, followed by BDE-99 and BDE-47. Although further research is required to gain baseline data on NBFRs in soil, the current state of scientific literature suggests that NBFRs pose a similar risk to land contamination as PBDEs.
اظهر المزيد [+] اقل [-]To what extent are microplastics from the open ocean weathered? النص الكامل
2017
ter Halle, Alexandra | Ladirat, Lucie | Martignac, Marion | Mingotaud, Anne-Françoise | Boyron, Olivier | Perez, Emile
It is necessary to better characterize plastic marine debris in order to understand its fate in the environment and interaction with organisms, the most common type of debris being made of polyethylene (PE) and polypropylene (PP). In this work, plastic debris was collected in the North Atlantic sub-tropical gyre during the Expedition 7th Continent sea campaign and consisted mainly in PE. While the mechanisms of PE photodegradation and biodegradation in controlled laboratory conditions are well known, plastic weathering in the environment is not well understood. This is a difficult task to examine because debris comes from a variety of manufactured objects, the original compositions and properties of which vary considerably. A statistical approach was therefore used to compare four sample sets: reference PE, manufactured objects, mesoplastics (5–20 mm) and microplastics (0.3–5 mm). Infrared spectroscopy showed that the surface of all debris presented a higher oxidation state than the reference samples. Differential scanning calorimetry analysis revealed that the microplastics were more crystalline contrarily to the mesoplastics which were similar to references samples. Size exclusion chromatography showed that the molar mass decreased from the references to meso- and microplastics, revealing a clear degradation of the polymer chains. It was thus concluded that the morphology of marine microplastic was much altered and that an unambiguous shortening of the polymer chains took place even for this supposedly robust and inert polymer.
اظهر المزيد [+] اقل [-]Role of snow in the fate of gaseous and particulate exhaust pollutants from gasoline-powered vehicles النص الكامل
2017
Nazarenko, Yevgen | Fournier, Sébastien | Kurien, Uday | Rangel-Alvarado, Rodrigo Benjamin | Nepotchatykh, Oleg | Seers, Patrice | Ariya, Parisa A.
Little is known about pollution in urban snow and how aerosol and gaseous air pollutants interact with the urban snowpack. Here we investigate interactions of exhaust pollution with snow at low ambient temperature using fresh snow in a temperature-controlled chamber. A gasoline-powered engine from a modern light duty vehicle generated the exhaust and was operated in homogeneous and stratified engine regimes. We determined that, within a timescale of 30 min, snow takes up from the exhaust a large mass of organic pollutants and aerosol particles, which were observed by electron microscopy, mass spectrometry and aerosol sizers. Specifically, the concentration of total organic carbon in the exposed snow increased from 0.948 ± 0.009 to 1.828 ± 0.001 mg/L (homogeneous engine regime) and from 0.275 ± 0.005 to 0.514 ± 0.008 mg/L (stratified engine regime). The concentrations of benzene, toluene and 13 out of 16 measured polycyclic aromatic hydrocarbons (PAHs), particularly naphthalene, benz[a]anthracene, chrysene and benzo[a]pyrene in snow increased upon exposure from near the detection limit to 0.529 ± 0.058, 1.840 ± 0.200, 0.176 ± 0.020, 0.020 ± 0.005, 0.025 ± 0.005 and 0.028 ± 0.005 ng/kg, respectively, for the homogeneous regime. After contact with snow, 50–400 nm particles were present with higher relative abundance compared to the smaller nanoparticles (<50 nm), for the homogeneous regime. The lowering of temperature from 25 ± 1 °C to (−8) – (−10) ± 1 °C decreased the median mode diameter of the exhaust aerosol particles from 69 nm to 57 nm (p < 0.1) and addition of snow to 51 nm (p < 0.1) for the stratified regime, but increased it from 20 nm to 27 nm (p < 0.1) for the homogeneous regime. Future studies should focus on cycling of exhaust-derived pollutants between the atmosphere and cryosphere. The role of the effects we discovered should be evaluated as part of assessment of pollutant loads and exposures in regions with a defined winter season.
اظهر المزيد [+] اقل [-]Oxidative stress and respiratory symptoms due to human exposure to polycyclic aromatic hydrocarbons (PAHs) in Kumasi, Ghana النص الكامل
2017
Bortey-Sam, Nesta | Ikenaka, Yoshinori | Akoto, Osei | Nakayama, Shouta M.M. | Asante, Kwadwo A. | Baidoo, Elvis | Obirikorang, Christian | Saengtienchai, Aksorn | Isoda, Norikazu | Nimako, Collins | Mizukawa, Hazuki | Ishizuka, Mayumi
Studies of polycyclic aromatic hydrocarbons (PAHs) and its metabolites in PM10, soils, rat livers and cattle urine in Kumasi, Ghana, revealed high concentrations and cancer potency. In addition, WHO and IARC have reported an increase in cancer incidence and respiratory diseases in Ghana. Human urine were therefore collected from urban and control sites to: assess the health effects associated with PAHs exposure using malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OHdG); identify any association between OH-PAHs, MDA, 8-OHdG with age and sex; and determine the relationship between PAHs exposure and occurrence of respiratory diseases. From the results, urinary concentrations of the sum of OH-PAHs (∑OHPAHs) were significantly higher from urban sites compared to the control site. Geometric mean concentrations adjusted by specific gravity, GMSG, indicated 2-OHNaphthalene (2-OHNap) (6.01 ± 4.21 ng/mL) as the most abundant OH-PAH, and exposure could be through the use of naphthalene-containing-mothballs in drinking water purification, insect repellent, freshener in clothes and/or “treatment of various ailments”. The study revealed that exposure to naphthalene significantly increases the occurrence of persistent cough (OR = 2.68, CI: 1.43–5.05), persistent headache (OR = 1.82, CI: 1.02–3.26), tachycardia (OR = 3.36, CI: 1.39–8.10) and dyspnea (OR = 3.07, CI: 1.27–7.43) in Kumasi residents. Highest level of urinary 2-OHNap (224 ng/mL) was detected in a female, who reported symptoms of persistent cough, headache, tachycardia, nasal congestion and inflammation, all of which are symptoms of naphthalene exposure according to USEPA. The ∑OHPAHs, 2-OHNap, 2-3-OHFluorenes, and -OHPhenanthrenes showed a significantly positive correlation with MDA and 4-OHPhenanthrene with 8-OHdG, indicating possible lipid peroxidation/cell damage or degenerative disease in some participants. MDA and 8-OHdG were highest in age group 21–60. The present study showed a significant sex difference with higher levels of urinary OH-PAHs in females than males.
اظهر المزيد [+] اقل [-]Anticancer drugs: Consumption trends in Spain, prediction of environmental concentrations and potential risks النص الكامل
2017
Franquet-Griell, Helena | Gómez-Canela, Cristian | Ventura, Francesc | Lacorte, Silvia
This study presents the occurrence and impact of 78 anticancer drugs compounds in Spanish river basins based on consumption data during the period 2010–2015 and calculation of the predicted environmental concentrations (PEC). The total consumption of anticancer drugs in Spanish pharmacies was of 23.4 tons in 2015, being mycophenolic acid and hydroxycarbamide the drugs with the highest prescription. Their PECs in river at national scale were up to 80 ng/L. However, the use of different dilution factors revealed major differences between hydrographic basins, and PECriver rose up to 68,014 ng/L in highly populated rivers with low flows. Concerning acute toxicity, there was no expected risk for the aquatic environment. However, chronic toxicity tests revealed possible long-term mutagenic effects for aquatic organisms. This study provides the tools for the estimation of PEC at river basin scale using time trend consumption data compilation. This information is very useful for prioritization of compounds of concern and permit to focus resources in environmental monitoring and risk evaluation.
اظهر المزيد [+] اقل [-]Assessment of chlorpyrifos toxic effects in zebrafish (Danio rerio) metabolism النص الكامل
2017
Gómez-Canela, Cristian | Prats, Eva | Piña, Benjamí | Tauler, Romà
Assessment of chlorpyrifos toxic effects in zebrafish (Danio rerio) metabolism النص الكامل
2017
Gómez-Canela, Cristian | Prats, Eva | Piña, Benjamí | Tauler, Romà
In this work the effect of chlorpyrifos exposure on metabolic profiles of zebrafish muscle was evaluated by liquid chromatography coupled to high resolution mass spectrometry. Different chemometric tools based on the selection of Regions of Interest and on Multivariate Curve-Resolution-Alternating Least Squares are proposed for the analysis of the complex data sets generated in the different exposure experiments. Analysis of Variance Simultaneous Component Analysis of changes on metabolite peak profile areas showed significant chlorpyrifos concentration and exposure time-dependent changes, clearly differentiating between exposed and non-exposed samples and between short (2 h) and long exposure times (6 h or 24 h). The changes observed in the concentrations of 50 muscle metabolites are indicative of induction of oxidative stress, of a general disruption of neurotransmitter metabolism, and of muscle exhaustion. These three effects are intimately related to the toxicity of chlorpyrifos.
اظهر المزيد [+] اقل [-]Assessment of chlorpyrifos toxic effects in zebrafish (Danio rerio) metabolism النص الكامل
2017
Gómez-Canela, Cristian | Prats, Eva | Piña, Benjamín | Tauler, Romà | European Research Council
In this work the effect of chlorpyrifos exposure on metabolic profiles of zebrafish muscle was evaluated by liquid chromatography coupled to high resolution mass spectrometry. Different chemometric tools based on the selection of Regions of Interest and on Multivariate Curve-Resolution-Alternating Least Squares are proposed for the analysis of the complex data sets generated in the different exposure experiments. Analysis of Variance Simultaneous Component Analysis of changes on metabolite peak profile areas showed significant chlorpyrifos concentration and exposure time-dependent changes, clearly differentiating between exposed and non-exposed samples and between short (2 h) and long exposure times (6 h or 24 h). The changes observed in the concentrations of 50 muscle metabolites are indicative of induction of oxidative stress, of a general disruption of neurotransmitter metabolism, and of muscle exhaustion. These three effects are intimately related to the toxicity of chlorpyrifos. © 2016 Elsevier Ltd | The research leading to these results has received funding from the European Research Council under European Union’s Seven Framework Programme (FP/2007-2013)/ERC Grant Agreement n.320737. | Peer reviewed
اظهر المزيد [+] اقل [-]Toxicokinetics and toxicodynamics of lead in the soil invertebrate Enchytraeus crypticus النص الكامل
2017
Zhang, Lulu | Van Gestel, Cornelis A.M.
The aim of the present study was to link Pb toxicokinetics to toxicodynamics in Enchytraeus crypticus. The enchytraeids were exposed for 14 d to different Pb concentrations (uptake phase) in natural Lufa 2.2 soil, followed by a 14-d elimination phase in clean soil. Pb accumulation and enchytraeid mortality were determined at different time intervals. At each exposure concentration, internal Pb concentration increased with exposure time and achieved equilibrium in approximately 7 d. Median lethal concentration (LC50) based on total Pb concentration in soil decreased with exposure time, but did not reach a steady-state level. Pb toxicity, therefore, showed a delay compared to accumulation in E. crypticus. LC50s based on internal Pb concentrations in the surviving animals did reach steady state in approx.14 d, suggesting that linking toxicokinetics to toxicodynamics may reduce the effects of time. This study highlighted that exposure time, as an important factor in metal uptake and toxicity, should be taken into account in ecotoxicological tests for risk assessment.
اظهر المزيد [+] اقل [-]Urinary paraben concentrations and their associations with anthropometric measures of children aged 3 years النص الكامل
2017
Guo, Jianqiu | Wu, Chunhua | Lu, Keng | Jiang, Shuai | Liang, Weijiu | Chang, Xiuli | Xu, Hao | Wang, Guoquan | Zhou, Zhijun
Parabens, known as ubiquitous preservatives, have been linked to adverse health outcomes in humans. This study aimed to examine urinary paraben concentrations of children at 3 years of age and evaluate their associations with anthropometric parameters. Urinary parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP) and benzylparaben (BeP) were measured among 436 children in a birth cohort using gas chromatography with tandem mass spectrometry. Generalized linear models were performed to evaluate associations of paraben exposures with age- and sex-specific z scores, including weight, height, weight for height and body mass index. MeP, EtP and PrP were the dominant parabens in urinary samples, with the median concentrations of 6.03 μg/L, 3.17 μg/L, 2.40 μg/L, respectively. The median values of estimated daily intake (EDIurine) of five urinary paraben concentrations were 12.10, 5.68, 4.50, 0.06 and 0.17 μg/kg-body weight/day, respectively. Urinary EtP concentrations were positively associated with weight z scores [regression coefficient β = 0.16, 95% confidence interval (CI): 0.04, 0.29; p = 0.01] and height z scores (β = 0.15, 95% CI: 0.03, 0.27; p = 0.01). Positive associations were found between the sum of molar concentrations of five parabens and height z scores among all children (β = 0.24, 95% CI: 0.04, 0.45; p = 0.02). These significant associations were only observed in boys. Our findings suggest that exposure to parabens may be adversely associated with physical growth in 3-year-old boy children. Further prospective studies are warranted to understand the toxicological mechanisms of paraben exposures and potential risk of children.
اظهر المزيد [+] اقل [-]Decomposition characteristics of three different kinds of aquatic macrophytes and their potential application as carbon resource in constructed wetland النص الكامل
2017
Wu, Suqing | He, Shengbing | Zhou, Weili | Gu, Jianya | Huang, Jungchen | Gao, Lei | Zhang, Xu
Decomposition of aquatic macrophytes usually generates significant influence on aquatic environment. Study on the aquatic macrophytes decomposition may help reusing the aquatic macrophytes litters, as well as controlling the water pollution caused by the decomposition process. This study verified that the decomposition processes of three different kinds of aquatic macrophytes (water hyacinth, hydrilla and cattail) could exert significant influences on water quality of the receiving water, including the change extent of pH, dissolved oxygen (DO), the contents of carbon, nitrogen and phosphorus, etc. The influence of decomposition on water quality and the concentrations of the released chemical materials both followed the order of water hyacinth > hydrilla > cattail. Greater influence was obtained with higher dosage of plant litter addition. The influence also varied with sediment addition. Moreover, nitrogen released from the decomposition of water hyacinth and hydrilla were mainly NH3-N and organic nitrogen while those from cattail litter included organic nitrogen and NO3⁻-N. After the decomposition, the average carbon to nitrogen ratio (C/N) in the receiving water was about 2.6 (water hyacinth), 5.3 (hydrilla) and 20.3 (cattail). Therefore, cattail litter might be a potential plant carbon source for denitrification in ecological system of a constructed wetland.
اظهر المزيد [+] اقل [-]Biomarker responses in zebrafish (Danio rerio) larvae exposed to pristine low-density polyethylene fragments النص الكامل
2017
Karamī, ʻAlī | Groman, David B. | Wilson, Scott P. | Ismail, Patimah | Neela, Vasantha K.
There are serious concerns over the adverse impacts of microplastics (MPs) on living organisms. The main objective of this study was to test the effects of MPs on the total length, weight, condition factor (CF), transcriptional level of antioxidant, anti and pro-apoptotic, and neurotransmitter genes, and the histopathology of the gill, liver, brain, kidney, and intestine in the larvae of zebrafish (Danio rerio). Fish were exposed to one of three levels of pristine low-density polyethylene (LDPE) fragments (5, 50, or 500 μg/L) for 10 or 20 days. No significant changes were observed in any of the selected biomarkers across MP concentrations at days 10 or 20. The expression of casp9 (caspase 9, apoptosis-related cysteine protease), casp3a (caspase 3, apoptosis-related cysteine protease a) and cat (catalase), however, were significantly lower in the larvae sampled at day 20 than day 10. We provide evidence that virgin short-term exposure to LDPE fragments has minimal impact on biomarker responses in D. rerio larvae.
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