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Perfluorinated alkylated substances in vegetables collected in four European countries; occurrence and human exposure estimations النص الكامل
2013
Herzke, Dorte | Huber, Sandra | Bervoets, Lieven | D’Hollander, Wendy | Hajslova, Jana | Pulkrabova, Jana | Brambilla, Gianfranco | De Filippis, Stefania Paola | Klenow, Stefanie | Heinemeyer, Gerhard | Voogt, Pim de
Perfluorinated alkylated substances in vegetables collected in four European countries; occurrence and human exposure estimations النص الكامل
2013
Herzke, Dorte | Huber, Sandra | Bervoets, Lieven | D’Hollander, Wendy | Hajslova, Jana | Pulkrabova, Jana | Brambilla, Gianfranco | De Filippis, Stefania Paola | Klenow, Stefanie | Heinemeyer, Gerhard | Voogt, Pim de
The human diet is recognised as one possible major exposure route to the overall perfluorinated alkylated substances (PFAS) burden of the human population, resulting directly from contamination of dietary food items, as well as migration of PFAS from food packaging or cookware. Most European countries carry out national monitoring programs (food basket studies) to monitor contamination with pollutants. Usually, for PFASs, non-coordinated approaches are used in Europe, since food basket studies are mainly carried out by national authorities following national requirements and questions, making comparisons between different countries difficult. A harmonised sampling campaign collecting similar food items in a uniform procedure enabling direct comparison between different regions in Europe was designed. We selected four countries (Belgium, Czech Republic, Italy and Norway), representing the four regions of Europe: West, East, South and North. In spring 2010 and 2011, 20 different types of vegetables were sampled in Belgium, Czech Republic, Italy and Norway. Perfluorinated carboxylic acids (PFCAs) were the main group of detected PFASs, with perfluorinated octanoic acid (PFOA) as the most abundant PFCA (with exception of samples from Czech Republic), followed by perfluorinated hexanoic acid and perfluorinated nonanoic acid. Dietary intake estimates for PFOA show only low human exposure due to vegetable consumption for adults and children, mostly governed by high intake of potatoes.
اظهر المزيد [+] اقل [-]Perfluorinated alkylated substances in vegetables collected in four European countries; occurrence and human exposure estimations النص الكامل
2013
Herzke, D. | Huber, S. | Bervoets, L. | D’Hollander, W. | Hajslova, J. | Pulkrabova, J. | Brambilla, G. | Filippis, S. P. | Klenow, S. | Heinemeyer, G. | Voogt, P.
The human diet is recognised as one possible major exposure route to the overall perfluorinated alkylated substances (PFAS) burden of the human population, resulting directly from contamination of dietary food items, as well as migration of PFAS from food packaging or cookware. Most European countries carry out national monitoring programs (food basket studies) to monitor contamination with pollutants. Usually, for PFASs, non-coordinated approaches are used in Europe, since food basket studies are mainly carried out by national authorities following national requirements and questions, making comparisons between different countries difficult. A harmonised sampling campaign collecting similar food items in a uniform procedure enabling direct comparison between different regions in Europe was designed. We selected four countries (Belgium, Czech Republic, Italy and Norway), representing the four regions of Europe: West, East, South and North. In spring 2010 and 2011, 20 different types of vegetables were sampled in Belgium, Czech Republic, Italy and Norway. Perfluorinated carboxylic acids (PFCAs) were the main group of detected PFASs, with perfluorinated octanoic acid (PFOA) as the most abundant PFCA (with exception of samples from Czech Republic), followed by perfluorinated hexanoic acid and perfluorinated nonanoic acid. Dietary intake estimates for PFOA show only low human exposure due to vegetable consumption for adults and children, mostly governed by high intake of potatoes.
اظهر المزيد [+] اقل [-]Adaptive alterations in the fatty acids composition under induced oxidative stress in heavy metal-tolerant filamentous fungus Paecilomyces marquandii cultured in ascorbic acid presence النص الكامل
2013
Słaba, Mirosława | Gajewska, Ewa | Bernat, Przemysław | Fornalska, Magdalena | Długoński, Jerzy
The ability of the heavy metal-tolerant fungus Paecilomyces marquandii to modulate whole cells fatty acid composition and saturation in response to IC₅₀ of Cd, Pb, Zn, Ni, and Cu was studied. Cadmium and nickel caused the most significant growth reduction. In the mycelia cultured with all tested metals, with the exception of nickel, a rise in the fatty acid unsaturation was noted. The fungus exposure to Pb, Cu, and Ni led to significantly higher lipid peroxidation. P. marquandii incubated in the presence of the tested metals responded with an increase in the level of linoleic acid and escalation of electrolyte leakage. The highest efflux of electrolytes was caused by lead. In these conditions, the fungus was able to bind up to 100 mg g⁻¹ of lead, whereas the content of the other metals in the mycelium was significantly lower and reached from 3.18 mg g⁻¹ (Cu) to 15.21 mg g⁻¹ (Zn). Additionally, it was shown that ascorbic acid at the concentration of 1 mM protected fungal growth and prevented the changes in the fatty acid composition and saturation but did not alleviate lipid peroxidation or affect the increased permeability of membranes after lead exposure. Pro-oxidant properties of ascorbic acid in the copper-stressed cells manifested strong growth inhibition and enhanced metal accumulation as a result of membrane damage. Toxic metals action caused cellular modulations, which might contributed to P. marquandii tolerance to the studied metals. Moreover, these changes can enhance metal removal from contaminated environment.
اظهر المزيد [+] اقل [-]Cadmium accumulation, activities of antioxidant enzymes, and malondialdehyde (MDA) content in Pistia stratiotes L النص الكامل
2013
Li, Yong | Zhang, Shanshan | Jiang, Wusheng | Liu, Donghua
The aquatic plant Pistia stratiotes L. (water lettuce) was studied due to its capability of absorption of contaminants in water and its subsequent use in wetlands constructed for wastewater treatment. The effects of Cd on root growth, accumulation of Cd, antioxidant enzymes, and malondialdehyde (MDA) content in P. stratiotes were investigated. The results indicated that P. stratiotes has considerable ability to accumulate Cd. Cadmium induced higher superoxide dismutase (SOD) and peroxidase (POD) activities than catalase activity, suggesting that SOD and POD provided a better defense mechanism against Cd-induced oxidative damage. The accumulation of Cd promoted MDA production.
اظهر المزيد [+] اقل [-]The acute effects of fine particles on respiratory mortality and morbidity in Beijing, 2004–2009 النص الكامل
2013
Li, Pei | Xin, Jinyuan | Wang, Yuesi | Wang, Shigong | Li, Guoxing | Pan, Xiaochuan | Liu, Zirui | Wang, Lili
Recent epidemiological and toxicological studies have shown associations between particulate matter and human health. However, the estimates of adverse health effects are inconsistent across many countries and areas. The stratification and interaction models were employed within the context of the generalized additive Poisson regression equation to examine the acute effects of fine particles on respiratory health and to explore the possible joint modification of temperature, humidity, and season in Beijing, China, for the period 2004-2009. The results revealed that the respiratory health damage threshold of the PM2.5 concentration was mainly within the range of 20-60 μg/m(3), and the adverse effect of excessively high PM2.5 concentration maintained a stable level. In the most serious case, an increase of 10 μg/m(3) PM2.5 results in an elevation of 4.60 % (95 % CI 3.84-4.60 %) and 4.48 % (95 % CI 3.53-5.41 %) with a lag of 3 days, values far higher than the average level of 0.69 % (95 % CI 0.54-0.85 %) and 1.32 % (95 % CI 1.02-1.61 %) for respiratory mortality and morbidity, respectively. There were strong seasonal patterns of adverse effects with the seasonal variation of temperature and humidity. The growth rates of respiratory mortality and morbidity were highest in winter. And, they increased 1.4 and 1.8 times in winter, greater than in the full year as PM2.5 increased 10 μg/m(3).
اظهر المزيد [+] اقل [-]Toxicokinetics of tilapia following high exposure to waterborne and dietary copper and implications for coping mechanisms النص الكامل
2013
Tsai, Jeng-Wei | Ju, Yun-Ru | Huang, Ying-Hsuan | Deng, Yue-Sun | Chen, Wei-Yu | Wu, Chin-Ching | Liao, Chung-Min
One of the major challenges in assessing the potential metal stress to aquatic organisms is explicitly predicting the internal dose in target organs. We aimed to understand the main sources of copper (Cu) accumulation in target organs of tilapia (Oreochromis mossambicus) and to investigate how the fish alter the process of Cu uptake, depuration, and accumulation (toxicokinetics (TK)) under prolonged conditions. We measured the temporal Cu profiles in selected organs after single and combined exposure to waterborne and dietary Cu for 14 days. Quantitative relations between different sources and levels of Cu, duration of treatment, and organ-specific Cu concentrations were established using TK modeling approaches. We show that water was the main source of Cu in the gills (>94 %), liver (>89 %), and alimentary canal (>86 %); the major source of Cu in the muscle (>51 %) was food. Cu uptake and depuration in tilapia organs were mediated under prolonged exposure conditions. In general, the uptake rate, depuration rate, and net bioaccumulation ability in all selected organs decreased with increasing waterborne Cu levels and duration of exposure. Muscle played a key role in accounting for the rapid Cu accumulation in the first period after exposure. Conversely, the liver acted as a terminal Cu storage site when exposure was extended. The TK processes of Cu in tilapia were highly changed under higher exposure conditions. The commonly used bioaccumulation model might lead to overestimations of the internal metal concentration with the basic assumption of constant TK processes.
اظهر المزيد [+] اقل [-]Nopalea cochenillifera, a potential chromium (VI) hyperaccumulator plant النص الكامل
2013
Adki, Vinayak S. | Jadhav, Jyoti P. | Bapat, Vishwas A.
Hexavalant chromium [Cr(VI)] tolerance and accumulation in in vitro grown Nopalea cochenillifera Salm. Dyck. plants was investigated. A micropropagation protocol was establish for a rapid multiplication of N. cochenillifera and [Cr(VI)] tolerance and accumulation was studied in in vitro grown cultures. Cr concentration was estimated by atomic absorption spectroscopy in roots and shoots to confirm plant’s hyperaccumulation capacity. Plants showed tolerance up to 100 μM K₂Cr₂O₇ without any significant changes in root growth after 16 days treatment; whereas, chlorophyll content in plants treated with 1 and 10 μM K₂Cr₂O₇ were not so different than the control plant. The levels of lipid peroxidation and protein oxidation increased significantly (p < 0.01) with increasing concentration of chromium. Exposures of N. cochenillifera to lower concentrations of K₂Cr₂O₇ (≤10 μM) induced catalase (CAT) and superoxide dismutase (SOD) significantly (p < 0.001) but higher concentrations of K₂Cr₂O₇ (>100 μM) inhibited the activities of CAT and SOD. Roots accumulated a maximum of 25,263.396 ± 1,722.672 mg Cr Kg⁻¹ dry weight (DW); while the highest concentration of Cr in N. cochenillifera shoots was 705.714 ± 32.324 mg Cr Kg⁻¹ DW. N. cochenillifera could be a prospective hyperaccumulator plant of Cr(VI) and a promising candidate for phytoremediation purposes.
اظهر المزيد [+] اقل [-]Eukaryotic diversity in premise drinking water using 18S rDNA sequencing: implications for health risks النص الكامل
2013
Buse, Helen Y. | Lu, Jingrang | Struewing, Ian T. | Ashbolt, Nicholas J.
The goal of this study was to characterize microbial eukaryotes over a 12-month period to provide insight into the occurrence of potential bacterial predators and hosts in premise plumbing. Nearly 6,300 partial 18S rRNA gene sequences from 24 hot (36.9-39.0 °C) and cold (6.8-29.1 °C) drinking water samples were analyzed and classified into major eukaryotic groups. Each major group, consisting of free-living amoebae (FLA)/protozoa, algae, copepods, dinoflagellates, fungi, nematodes, and unique uncultured eukaryotic sequences, showed limited diversity dominated by a few distinct populations, which may be characteristic of oligotrophic environments. Changes in the relative abundance of predators such as nematodes, copepods, and FLA appear to be related to temperature and seasonal changes in water quality. Sequences nearly identical to FLA such as Hartmannella vermiformis, Echinamoeba thermarmum, Pseudoparamoeba pagei, Protacanthamoeba bohemica, Platyamoeba sp., and Vannella sp. were obtained. In addition to FLA, various copepods, rotifers, and nematodes have been reported to internalize viral and bacterial pathogens within drinking water systems thus potentially serving as transport hosts; implications of which are discussed further. Increasing the knowledge of eukaryotic occurrence and their relationship with potential pathogens should aid in assessing microbial risk associated with various eukaryotic organisms in drinking water.
اظهر المزيد [+] اقل [-]Comparative analysis of selected biomarkers and pesticide sensitivity in juveniles of Solea solea and Solea senegalensis النص الكامل
2013
Sànchez-Nogué, B. | Varó, I. | Solé, M.
Comparative analysis of selected biomarkers and pesticide sensitivity in juveniles of Solea solea and Solea senegalensis النص الكامل
2013
Sànchez-Nogué, B. | Varó, I. | Solé, M.
The common sole, Solea solea (Linneus, 1758), and the Senegalese sole, Solea senegalensis (Kaup, 1858), are two important commercial species that coexist in the NW Mediterranean. In order to assess the species' ability to respond to chemical insults, a comparison of activities on enzymes involved in xenobiotic metabolism was carried out. Juveniles of both species were sampled in winter 2011 from the Ebro Delta region, and activities of selected enzymes such as acetylcholinesterase (AChE), carboxylesterase (CbE), ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) were determined in several tissues. Lipid peroxidation (LP) levels in plasma were measured as a sign of oxidative stress. In vitro exposures to selected pesticides were contrasted, analysing AChE and CbE activities in several tissue homogenates. Overall, enzymatic activities were higher in S. solea except for gill GST and CbE and kidney GST, while plasmatic LP levels were similar. In vitro contrasts revealed lower IC50 values for CbE activities in S. solea, suggesting a greater buffer capacity of this enzyme to potentially reduce pesticide toxicity over AChE.
اظهر المزيد [+] اقل [-]Comparative analysis of selected biomarkers and pesticide sensitivity in juveniles of Solea solea and Solea senegalensis النص الكامل
2013
Sánchez-Nogué, B. | Varó, Inmaculada | Solé, Montserrat
The common sole, Solea solea (Linneus, 1758), and the Senegalese sole, Solea senegalensis (Kaup, 1858), are two important commercial species that coexist in the NW Mediterranean. In order to assess the species' ability to respond to chemical insults, a comparison of activities on enzymes involved in xenobiotic metabolism was carried out. Juveniles of both species were sampled in winter 2011 from the Ebro Delta region, and activities of selected enzymes such as acetylcholinesterase (AChE), carboxylesterase (CbE), ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) were determined in several tissues. Lipid peroxidation (LP) levels in plasma were measured as a sign of oxidative stress. In vitro exposures to selected pesticides were contrasted, analysing AChE and CbE activities in several tissue homogenates. Overall, enzymatic activities were higher in S. solea except for gill GST and CbE and kidney GST, while plasmatic LP levels were similar. In vitro contrasts revealed lower IC50 values for CbE activities in S. solea, suggesting a greater buffer capacity of this enzyme to potentially reduce pesticide toxicity over AChE. © 2012 Springer-Verlag Berlin Heidelberg. | This work was financed by the Ministry of Science and Innovation of Spain (ref CTM2010-16611). | Peer Reviewed
اظهر المزيد [+] اقل [-]Numerical modeling on air quality in an urban environment with changes of the aspect ratio and wind direction النص الكامل
2013
Yassin, Mohamed F.
Due to heavy traffic emissions within an urban environment, air quality during the last decade becomes worse year by year and hazard to public health. In the present work, numerical modeling of flow and dispersion of gaseous emissions from vehicle exhaust in a street canyon were investigated under changes of the aspect ratio and wind direction. The three-dimensional flow and dispersion of gaseous pollutants were modeled using a computational fluid dynamics (CFD) model which was numerically solved using Reynolds-averaged Navier–Stokes (RANS) equations. The diffusion flow field in the atmospheric boundary layer within the street canyon was studied for different aspect ratios (W/H = 1/2, 3/4, and 1) and wind directions (θ = 90°, 112.5°, 135°, and 157.5°). The numerical models were validated against wind tunnel results to optimize the turbulence model. The numerical results agreed well with the wind tunnel results. The simulation demonstrated that the minimum concentration at the human respiration height within the street canyon was on the windward side for aspect ratios W/H = 1/2 and 1 and wind directions θ = 112.5°, 135°, and 157.5°. The pollutant concentration level decreases as the wind direction and aspect ratio increase. The wind velocity and turbulence intensity increase as the aspect ratio and wind direction increase.
اظهر المزيد [+] اقل [-]Dioxin/POPs legacy of pesticide production in Hamburg: Part 1—securing of the production area النص الكامل
2013
Weber, Roland | Varbelow, Hans Gerhard
α-Hexachlorocyclohexane (HCH), β-HCH, and γ-HCH (lindane) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention. Therefore, the chemicals need to be globally addressed, including the disposal of historic wastes. At most sites, the approximately 85 % of HCH waste isomers were dumped. At a former lindane factory in Hamburg and some other factories the HCH, waste was recycled producing residues with high polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDF) levels. The soil and ground water under the former pesticide factory was/is highly contaminated with HCH (260 tons), chlorobenzenes (550 tons), and PCDD/PCDF (6 kg toxic equivalents (TEQ)). This contamination did not result from disposal operations but from spillages and leakages during the 30 years of the factory's production history. A containment wall has been constructed around the production area to prevent the dispersal of the pollutants. The ground water is managed by a pump and treat system. Over the last 15 years, approximately 10–30 tons of this pollution reservoir has been pumped and incinerated. For the contaminated production buildings, specific assessment and demolition technologies have been applied. In addition to their HCH waste isomer deposition, former lindane/HCH productions need to be assessed for possible recycling practice of HCH and related PCDD/PCDF contamination of the production area and buildings. Since such recycling activities have taken place at several factories in different countries, the experience of assessment and management of the described production area and contaminated buildings could be valuable. Such assessment could be addressed within the frame of the Stockholm Convention.
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