Effects of realistic concentrations of TiO<Subscript>2</Subscript> and ZnO nanoparticles in <Emphasis Type="Italic">Prochilodus lineatus</Emphasis> juvenile fish

The impact of nanoparticles on fish health is still a matter of debate, since nanotechnology is quite recent. In this study, freshwater benthonic juvenile fish Prochilodus lineatus were exposed through water to three concentrations of TiO₂ (0.1, 1, and 10 μg l^?1) and ZnO (7, 70, and 700 μg l^?1) nanoparticles, as well as to a mixture of both (TiO₂ 1 μg l^?1?+?ZnO 70 μg l^?1) for 5 and 30 days. Nanoparticle characterization revealed an increase of aggregate size in the function of concentration, but suspensions were generally stable. Fish mortality was high at subchronic exposure to 70 and 700 μg l^?1 of ZnO. Nanoparticle exposure led to decreased acetylcholinesterase activity either in the muscle or in the brain, depending on particle composition (muscle—TiO₂ 10 μg l^?1; brain—ZnO 7 and 700 μg l^?1), and protein oxidative damage increased in the brain (ZnO 70 μg l^?1) and gills (ZnO 70 μg l^?1 and mixture) but not in the liver. Exposed fish had more frequent alterations in the liver (necrosis, vascular congestion, leukocyte infiltration, and basophilic foci) and gills (hyperplasia and epithelial damages, e.g., epithelial disorganization and epithelial loss) than the control fish. Thus, predicted concentrations of TiO₂ and ZnO nanoparticles caused detectable effects on P. lineatus that may have important consequences to fish health. But, these effects are much more subtle than those usually reported in the scientific literature for high concentrations or doses of metal nanoparticles.     

Evaluation of toxic metal (Hg, Cd, Pb), polychlorinated biphenyl (PCBs), and pesticide (DDTs) levels in aromatic herbs collected in selected areas of Southern Italy

This study provides, for the first time, data regarding levels of toxic metals (Hg, Cd, and Pb) and organochlorine compounds (PCBs and DDTs) in various aromatic herbs as rosemary (Rosmarinus officinalis), sage (Salvia officinalis), laurel (Laurus nobilis), oregano (Origanum vulgare), and spearmint (Mentha viridis) collected in some towns of the Southern Italy with different anthropogenic and population pressure. Metal and organochlorine compound concentrations were determined using atomic absorption spectrophotometer and gas-chromatography mass spectrometer (GC/MS), respectively. Pb emerged as the most abundant element, followed by Cd and Hg, while between organochlorine compounds, PCB concentrations were higher than those of DDTs. The pollutant concentrations were found to vary depending on the different herbs. The highest Pb levels were observed in rosemary (1.66 μg g^?1 dry weight) and sage (1.41 μg g^?1 dry weight), this latter showing also the highest Cd concentrations (0.75 μg g^?1 dry weight). For PCBs, the major concentrations were found in rosemary (2.75 ng g^?1 dry weight) and oregano (2.39 ng g^?1 dry weight). The principal component analysis applied in order to evaluate possible similarities and/or differences in the contamination levels among sampling sites indicated differences area-specific contamination.     

Assessing the enrichment of heavy metals in surface soil and plant (Digitaria eriantha) around coal-fired power plants in South Africa

Nine metals (Fe, Cu, Mn, Ni, Cd, Pb, Hg, Cr, and Zn) were determined in soil and Digitaria eriantha plants within the vicinity of three coal power plants (Matla, Lethabo, and Rooiwal), using ICP-OES and GFAAS. The total metal concentration in soil ranged from 0.05?±?0.02 to 1836?±?70 μg g^?1, 0.08?±?0.05 to 1744?±?29 μg g^?1, and 0.07?±?0.04 to 1735?±?91 μg g^?1 in Matla, Lethabo, and Rooiwal, respectively. Total metal concentration in the plant (D. eriantha) ranged from 0.005?±?0.003 to 535?±?43 μg g^?1 in Matla, 0.002?±?0.001 to 400?±?269 μg g^?1 in Lethabo, and 0.002?±?0.001 to 4277?±?201 μg g^?1 in Rooiwal. Accumulation factors (A) of less than 1 (i.e., 0.003 to 0.37) at all power plants indicate a low transfer of metal from soil to plant (excluder). Enrichment factor values obtained (2.4–5.0) indicate that the soils are moderately enriched with the exception of Pb that had significant enrichment of 20. Geo-accumulation index (I-geo) values of metals indicate that the soils are moderately polluted (0.005–0.65), except for Pb that showed moderate to strong pollution (1.74–2.53).     

Single and combined effects of aluminum (Al<Subscript>2</Subscript>O<Subscript>3</Subscript>) and zinc (ZnO) oxide nanoparticles in a freshwater fish, <Emphasis Type="Italic">Carassius auratus</Emphasis>

The increasing use of nanoparticles (NPs) worldwide has raised some concerns about their impact on the environment. The aim of the study was to assess the toxicity of metal oxide nanoparticles, singly or combined, in a freshwater fish (Carassius auratus). The fish were exposed for 7, 14, and 21 days to different concentrations of NPs (10 μg Al₂O₃.L^?1, 10 μg ZnO.L^?1, 10 μg Al₂O₃.L^?1 plus 10 μg ZnO.L^?1, 100 μg Al₂O₃.L^?1, 100 μg ZnO.L^?1, and 100 μg Al₂O₃.L^?1 plus 100 μg ZnO.L^?1). At the end of each exposure period, antioxidant enzyme activity (catalase, glutathione-S-transferase, and superoxide dismutase), lipid peroxidation, and histopathology were assessed in the gills and livers of C. auratus. The results show an increase in catalase (CAT) and superoxide dismutase (SOD) activity in the gills and livers of fish, especially after 14 days of exposure to single and combined NPs, followed by a reduction at 21 days. An increase in glutathione S-transferase (GST) was observed in gills after 7 days for all tested NP concentrations (single and combined); while in livers, a significant increase was determined after 14 days of exposure to 100 μg.L^?1 of both single ZnO and Al₂O₃ NPs. Lipid peroxidation (LPO) significantly increased in gills after 7 days of exposure to 100 μg.L^?1 Al₂O₃ NPs (single or combined). In livers, LPO increased significantly after 7 days of exposure to all tested concentrations of both single ZnO and Al₂O₃ (except for 10 μg Al₂O₃.L^?1), and after 14 days of exposure to ZnO (10 and 100 μg.L^?1) and Al₂O₃ (100 μg.L^?1)_. The results from histological observations suggest that exposure to metal oxide NPs affected both livers and gills, presenting alterations such as gill hyperplasia and liver degeneration. However, the most pronounced effects were found in gills. In general, this study shows that the tested NPs, single or combined, are capable of causing sub-lethal effects on C. auratus, but when combined, NPs seem to be slightly more toxic than when added alone.     

Metal content in caviar of wild Persian sturgeon from the southern Caspian Sea

Caviar (fish roe of sturgeon) may contain high levels of contaminants. An inductively coupled plasma-optical emission spectrometer and a direct mercury analyzer were used to assess the contents of four heavy metals (Hg, Se, Sn, and Ba) in caviar of wild Persian sturgeon sea foods. The levels of Hg ranged from 1.39 to 1.50 μg?g^?1, Se from 0.90 to 1.10 μg?g^?1, Sn from 0.23 to 0.33, and Ba from 0.71 to 1.17 μg?g^?1. Evaluation of these levels showed that except for Hg, the average concentrations of other metals are significantly lower than adverse level for the human consumption when compared with Food and Agricultural Organization of the United Nations and World Health Organization permissible limits. Therefore, their contribution to the total body burden of these heavy metals can be considered as negligibly small given that caviar is a luxury product.     

Psychotropic drugs in mixture alter swimming behaviour of Japanese medaka (<Emphasis Type="Italic">Oryzias latipes</Emphasis>) larvae above environmental concentrations

Psychiatric pharmaceuticals, such as anxiolytics, sedatives, hypnotics and antidepressors, are among the most prescribed active substances in the world. The occurrence of these compounds in the environment, as well as the adverse effects they can have on non-target organisms, justifies the growing concern about these emerging environmental pollutants. This study aims to analyse the effects of six psychotropic drugs, valproate, cyamemazine, citalopram, sertraline, fluoxetine and oxazepam, on the survival and locomotion of Japanese medaka Oryzias latipes larvae. Newly hatched Japanese medaka were exposed to individual compounds for 72 h, at concentrations ranging from 10 μg L^?1 to 10 mg L^?1. Lethal concentrations 50 % (LC₅₀) were estimated at 840, 841 and 9,136 μg L^?1 for fluoxetine, sertraline and citalopram, respectively, while other compounds did not induce any significant increase in mortality. Analysis of the swimming behaviour of larvae, including total distance moved, mobility and location, provided an estimated lowest observed effect concentration (LOEC) of 10 μg L^?1 for citalopram and oxazepam, 12.2 μg L^?1 for cyamemazine, 100 μg L^?1 for fluoxetine, 1,000 μg L^?1 for sertraline and >10,000 μg L^?1 for valproate. Realistic environmental mixture of the six psychotropic compounds induced disruption of larval locomotor behaviour at concentrations about 10- to 100-fold greater than environmental concentrations.     

Accumulation of Cr,Cd, Pb,Cu, and Zn by plants in tanning sludge storage sites: opportunities for contamination bioindication and phytoremediation

Tanning sludge enriched with high concentrations of Cr and other metals has adverse effects on the environment. Plants growing in the metalliferous soils may have the ability to cope with high metal concentrations. This study focuses on potentials of using native plants for bioindication and/or phytoremediation of Cr-contaminated sites. In the study, we characterized plants and soils from six tanning sludge storage sites. Soil in these sites exhibited toxic levels of Cr (averaged 16,492 mg kg^?1) and other metals (e.g., 48.3 mg Cu kg^?1, 2370 mg Zn kg^?1, 44.9 mg Pb kg^?1, and 0.59 mg Cd kg^?1). Different metal tolerance and accumulation patterns were observed among the sampled plant species. Phragmites australis, Zephyranthes candida, Cynodon dactylon, and Alternanthera philoxeroides accumulated moderate-high concentrations of Cr and other metals, which could make them good bioindicators of heavy metal pollution. High Cr and other metal concentrations (e.g., Cd and Pb) were found in Chenopodium rubrum (372 mg Cr kg^?1), Aster subulatus (310 mg Cr kg^?1), and Brassica chinensis (300 mg Cr kg^?1), being considered as metal accumulators. In addition, Nerium indicum and Z. candida were able to tolerate high concentrations of Cr and other metals, and they may be used as preferable pioneer species to grow or use for restoration in Cr-contaminated sites. This study can be useful for establishing guidelines to select the most suitable plant species to revegetate and remediate metals in tanning sludge-contaminated fields.     

Toxicity of atrazine and its bioaccumulation and biodegradation in a green microalga,Chlamydomonas mexicana

This study evaluated the toxicity of herbicide atrazine, along with its bioaccumulation and biodegradation in the green microalga Chlamydomonas mexicana. At low concentration (10 μg L^?1), atrazine had no profound effect on the microalga, while higher concentrations (25, 50, and 100 μg L^?1) imposed toxicity, leading to inhibition of cell growth and chlorophyll a accumulation by 22 %, 33 %, and 36 %, and 13 %, 24 %, and 27 %, respectively. Atrazine 96-h EC50 for C. mexicana was estimated to be 33 μg L^?1. Microalga showed a capability to accumulate atrazine in the cell and to biodegrade the cell-accumulated atrazine resulting in 14–36 % atrazine degradation at 10–100 μg L^?1. Increasing atrazine concentration decreased the total fatty acids (from 102 to 75 mg g^?1) and increased the unsaturated fatty acid content in the microalga. Carbohydrate content increased gradually with the increase in atrazine concentration up to 15 %. This study shows that C. mexicana has the capability to degrade atrazine and can be employed for the remediation of atrazine-contaminated streams.     

Mercury transfer from soil to olive trees. A comparison of three different contaminated sites

Mercury contents in soil and olive tree leaves have been studied in 69 plots around three different source areas of this element in Spain: Almadén (Ciudad Real), Flix (Tarragona) and Jódar (Jaén). Almadén was the world’s largest cinnabar (HgS) mining district and was active until 2003, Flix is the oldest Spanish chlor-alkali plant (CAP) and has been active from 1898 to the present day and Jódar is a decommissioned CAP that was active for 14 years (1977–1991). Total mercury contents have been measured by high-frequency modulation atomic absorption spectrometry with Zeeman effect (ZAAS-HFM) in the soils and olive tree leaves from the three studied areas. The average soil contents range from 182 μg kg^?1 in Flix to 23,488 μg kg^?1 in Almadén, while the average leaf content ranges from 161 μg kg^?1 in Jódar to 1213 μg kg^?1 in Almadén. Despite the wide range of data, a relationship between soil–leaf contents has been identified: in Almadén and Jódar, multiplicative (bilogarithmic) models show significant correlations (R?=?0.769 and R?=?0.484, respectively). Significant correlations were not identified between soil and leaf contents in Flix. The continuous activity of the Flix CAP, which remains open today, can explain the different uptake patterns for mercury, which is mainly atmospheric in origin, in comparison to the other two sites, where activity ceased more than 10 years ago and only soil uptake patterns based on the Michaelis–Menten enzymatic model curve are observed.     

Influence of short-time imidacloprid and acetamiprid application on soil microbial metabolic activity and enzymatic activity

The influence of two neonicotinoids, i.e., imidacloprid (IMI) and acetamiprid (ACE), on soil microbial activities was investigated in a short period of time using a combination of the microcalorimetric approach and enzyme tests. Thermodynamic parameters such as Q _T (J g^?1 soil), ?H _met (kJ mol^?1), J _Q/S (J g^?1 h^?1), k (h^?1), and soil enzymatic activities, dehydrogenase, phosphomonoesterase, arginine deaminase, and urease, were used to evaluate whole metabolic activity changes and acute toxicity following IMI and ACE treatment. Various profiles of thermogenic curves reflect different soil microbial activities. The microbial growth rate constant k, total heat evolution Q _T (expect for IMI), and inhibitory ratio I show linear relationship with the doses of IMI and ACE. Q _T for IMI increases at 0.0–20 μg g^?1 and then decreases at 20–80 μg g^?1, possibly attributing to the presence of tolerant microorganisms. The 50 % inhibitory ratios (IC₅₀) of IMI and ACE are 95.7 and 77.2 μg g^?1, respectively. ACE displays slightly higher toxicity than IMI. Plots of k and Q _T against microbial biomass-C indicate that the k and Q _T are growth yield-dependent. IMI and ACE show 29.6; 40.4 and 23.0; and 23.3, 21.7, and 30.5 % inhibition of dehydrogenase, phosphomonoesterase, and urease activity, respectively. By contrast, the arginine deaminase activity is enhanced by 15.2 and 13.2 % with IMI and ACE, respectively. The parametric indices selected give a quantitative dose-response relationship of both insecticides and indicate that ACE is more toxic than IMI due to their difference in molecular structures.     

Characterization of carbonaceous aerosols over Delhi in Ganga basin: seasonal variability and possible sources

The mass concentration of carbonaceous species, organic carbon (OC), and elemental carbon (EC) using a semicontinuous thermo-optical EC-OC analyzer, and black carbon (BC) using an Aethalometer were measured simultaneously at an urban mega city Delhi in Ganga basin from January 2011 to May 2012. The concentrations of OC, EC, and BC exhibit seasonal variability, and their concentrations were ～2 times higher during winter (OC 38.1?±?17.9 μg m^?3, EC 15.8?±?7.3 μg m^?3, and BC 10.1?±?5.3 μg m^?3) compared to those in summer (OC 14.1?±?4.3 μg m^?3, EC 7.5?±?1.5 μg m^?3, and BC 4.9?±?1.5 μg m^?3). A significant correlation between OC and EC (R?=?0.95, n?=?232) indicate their common emission sources with relatively lower OC/EC ratio (range 1.0–3.6, mean 2.2?±?0.5) suggests fossil fuel emission as a major source of carbonaceous aerosols over the station. On average, mass concentration of EC was found to be ～38 % higher than BC during the study period. The measured absorption coefficient (b_abs) was significantly correlated with EC, suggesting EC as a major absorbing species in ambient aerosols at Delhi. Furthermore, the estimated mass absorption efficiency (σ_abs) values are similar during winter (5.0?±?1.5 m² g^?1) and summer (4.8?±?2.8 m² g^?1). Significantly high aerosol loading of carbonaceous species emphasize an urgent need to focus on air quality management and proper impact assessment on health perspective in these regions.     

Polycyclic aromatic hydrocarbons and trace metals in mosque’s carpet dust of Riyadh,Saudi Arabia,and their health risk implications

The main objectives of this work were to identify and determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and trace metals in carpet dust samples from various mosques of the city of Riyadh and to assess the health risks associated with the exposure to these pollutants. Therefore, 31 samples of mosque’s carpet dust from Riyadh were collected. The results showed that 14 PAHs were present in the dust samples with concentrations ranged from 90 to 22,146 ng g^?1 (mean = 4096 ± 4277 ng g^?1) where low molecular weight compounds were dominant. The presence of PAHs were in the order of naphthalene > chrysene and benzo(b)fluoranthene > benzo(a)pyrene > acenaphthene and benzo(k)fluoranthene > pyrene and the absence of indeno(1,2,3-cd)pyrene and dibenz(a,h)anthracene. The diagnostic ratio coupled with principle component analysis (PCA) revealed mix sources of petrogenic from traffic, stack emission, and pyrogenic inputs from essence and perfumed wood burning. Trace metals were significant in the dust samples, and their concentrations decrease in the order of Zn, Mn, Cu, Cr, Pb, Ni, and V where Zn being the highest (94.4 ± 91.5 μg g^?1) and indium was the lowest (1.9 ± 9.3 μg g^?1). The trace metals were major in southern and central parts of Riyadh and followed the order of central Riyadh > southern Riyadh > western Riyadh > eastern Riyadh > northern Riyadh. Estimated risk based on the total PAHs was found to be 4.30 × 10^?11 for adult and 1.56 × 10^?11 for children. Elemental non-cancer risk for adults ranged from 7.9 × 10^?4 for Co to 7.58 × 10^?1 for Li and for children ranged from 3.70 × 10^?3 for Co to 3.54 for Li. Policy implication and mitigations of PAHs in Riyadh and Saudi Arabia were highlighted.     

Bioaccumulation and trophic transfer of mercury in a food web from a large, shallow, hypereutrophic lake (Lake Taihu) in China

Purpose

Due to the fast development of industry and the overuse of agrichemicals in past decades, Lake Taihu, an important source of aquatic products for Eastern China, has simultaneously suffered mercury (Hg) contamination and eutrophication. The objectives of this study are to understand Hg transfer in the food web in this eutrophic, shallow lake and to evaluate the exposure risk of Hg through fish consumption.

Methods

Biota samples including macrophytes, sestons, benthic animals, and fish were collected from Lake Taihu in the fall of 2009. The total mercury (THg), methyl mercury (MeHg), ??¹³C and ??¹⁵N in the samples were measured.

Results and discussion

The signature for ??¹⁵N increased with the trophic levels. Along with a diet composed of fish, the significant relationship between the ??¹³C and ??¹⁵N indicated that a pelagic foraging habitat is the dominant pathway for energy transfer in Lake Taihu. The concentrations of THg and MeHg in the organisms varied dramatically by ??3 orders of magnitude from primary producers (macrophytes and sestons) to piscivorous fish. The highest concentrations of both THg (100 ng g^?1) and MeHg (66 ng g^?1), however, were lower than the guideline of 200 ng g^?1 of MeHg for vulnerable populations that is recommended by the World Health Organization (WHO). The daily intake of THg and MeHg of 92 and 56 ng day^?1 kg^?1 body weight, respectively, was generally lower than the tolerable intake of 230 ng day^?1 kg^?1 body weight for children recommended by the Joint FAO/WHO Expert Committee on Food Additives. Significant relationships between the ??¹⁵N and the logarithm of THg and MeHg showed an obvious biomagnification of Hg along the food web. The logarithmic bioaccumulation factor of MeHg in the fish (up to 5.7) from Lake Taihu, however, was relatively low compared to that of other aquatic ecosystems.

Conclusion

Health risk of exposure to Hg by consumption of fish for local residents is relatively low in the Lake Taihu area. Dilution of Hg levels in the phytoplankton induced by eutrophication is a possible factor inhibiting accumulation of MeHg in fish in eutrophic Lake Taihu.     

Multivariate characterization of elements accumulated in Wolfiporia extensa mushroom from Yunnan province of China

ABSTRACT

Dried sclerotia of Wolfiporia extensa have been used as medicine in Asia from Eastern Han Dynasty, and also used as traditional snack called “fulingjiabing” in Beijing, China. In this paper, 18 macro and trace elements (Ag, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Li, Mn, Ni, Pb, Rb, Se, Sr, V, and Zn) in both flesh and peel of Wolfiporia extensa from seven sites of Yunnan province in China were determined by inductively coupled plasma mass spectrometer. The average recovery rates of certified reference materials for GBW10015 (spinach leaves) ranged from 90.5 to 113%, for GBW10028 (citrus leaves) from 92.8 to 106%, and for GBW07603 (bush branch and leaves) from 83.3 to 114.6%. Generally speaking, the concentration of all elements determined was at common level. The results of this survey indicate that mineral compositions in peel were higher than in flesh. In peel, the contents of investigated trace metals in mushroom samples were found to be in the range of 1,660–13,400 µg·g^?1 dry matter (dm) for Fe and 29.6–710 µg·g^?1 dm for Mn. The mean contents of Cr, Cu, Rb, V, and Zn in peel were between 10 and 20 µg·g^?1 dm, followed by As, Co, Li, Ni, Pb, Se, and Sr with mean contents between 1 and 10 µg·g^?1 dm, while Ag, Cd, and Cs had mean contents of <1 µg·g^?1 dm. In flesh, the concentration of Fe was in the range of 54–900 µg·g^?1 dm, and it was 1.5–49 µg·g^?1 dm for Mn, followed by Ba, Cu, Rb, and Zn in the range of 1 to 10 µg·g^?1 dm, while for Ag, As, Cd, Co, Cr, Cs, Li, Ni, Pb, Se, Sr, and V it was <1 µg·g^?1 dm. The concentration of toxic elements, such as As, Cd, and Pb, in both flesh and peel was below the permissible limits of World Health Organization. However, As and Pb contents in peel were higher than the limits permitted in the Chinese Pharmacopoeia. The results of principal component analysis showed that the flesh of Wolfiporia extensa from all the seven sites of the Yunnan province tend to cluster together, most probably because the origin of mineral elements in both flesh and peel is wood substrate (old and dead pine trees).     

Occurrence and distribution of veterinary antibiotics and tetracycline resistance genes in farmland soils around swine feedlots in Fujian Province, China

Six antibiotics, tetracyclines (TCs), and quinolones (QNs) in farmland soils from four coastal cities in Fujian Province of China were investigated. Oxytetracycline was most frequently detected, followed by enrofloxacin, ciprofloxacin, chlorotetracycline, ofloxacin, and tetracycline, with maximum concentrations of 613.2, 637.3, 237.3, 2668.9, 205.7, and 189.8 μg kg^?1, respectively. Samples from Putian City contained the highest maximum concentration of ∑TCs (3,064.2 μg kg^?1), whereas those from Fuzhou City contained the highest maximum concentration of ∑QNs (897.8 μg kg^?1). It is noteworthy that the ∑TCs and ∑QNs in 46.4 and 28.6 % of samples exceeded the ecotoxic effect trigger value (100 μg kg^?1), respectively. The concentrations of these antibiotics and five tetracycline resistance genes in four soil plots at depth profiles were quantified thereafter. In most cases, both antibiotics and resistance genes decreased with the increase of depth. Some antibiotics can be detected at a depth of 60–80 cm where the abundance of tetO, tetM, and tetX reached up to 10⁷ copies g^?1. Additionally, the sum of all tet genes (normalized to 16S rRNA genes) correlated with ∑TCs significantly (r?=?0.676). Our results suggest that resistance determinants can migrate to deeper soil layers and would probably contaminate groundwater by vertical transport.     

Removal mechanisms and kinetics of trace tetracycline by two types of activated sludge treating freshwater sewage and saline sewage

Understanding the removal mechanisms and kinetics of trace tetracycline by activated sludge is critical to both evaluation of tetracycline elimination in sewage treatment plants and risk assessment/management of tetracycline released to soil environment due to the application of biosolids as fertilizer. Adsorption is found to be the primary removal mechanism while biodegradation, volatilization, and hydrolysis can be ignored in this study. Adsorption kinetics was well described by pseudo-second-order model. Faster adsorption rate (k ₂?=?2.04?×?10^?2?g?min^?1?μg^?1) and greater adsorption capacity (q _e?=?38.8 μg?g^?1) were found in activated sludge treating freshwater sewage. Different adsorption rate and adsorption capacity resulted from chemical properties of sewage matrix rather than activated sludge surface characteristics. The decrease of tetracycline adsorption in saline sewage was mainly due to Mg²⁺ which significantly reduced adsorption distribution coefficient (K _d) from 12,990?±?260 to 4,690?±?180 L?kg^?1. Species-specific adsorption distribution coefficients followed the order of $ K_{\mathrm{d}}^{{ + 00}} \gg K_{\mathrm{d}}^{{ + - 0}} > K_{\mathrm{d}}^{{ + - - }} $ . Contribution of zwitterionic tetracycline to the overall adsorption was >90 % in the actual pH range in aeration tank. Adsorption of tetracycline in a wide range of temperature (10 to 35 °C) followed the Freundlich adsorption isotherm well.     

Particulate matter in the indoor and outdoor air of a gymnasium and a fronton

An indoor/outdoor monitoring programme of PM₁₀ was carried out in two sports venues (a fronton and a gymnasium). Levels always below 50 μg m^?3 were obtained in the fronton and outdoor air. Due to the climbing chalk and the constant process of resuspension, concentrations above 150 μg m^?3 were registered in the gymnasium. The chalk dust contributed to CO₃ ^2? concentrations of 32?±?9.4 μg m^?3 in this sports facility, which represented, on average, 18 % of the PM₁₀ mass. Here, the carbonate levels were 128 times higher than those registered outdoors. Much lower concentrations, around 1 μg m^?3, were measured in the fronton. The chalk dust is also responsible for the high Mg²⁺ concentrations in the gym (4.7?±?0.89 μg m^?3), unfolding a PM₁₀ mass fraction of 2.7 %. Total carbon accounted for almost 30 % of PM₁₀ in both indoor spaces. Aerosol size distributions were bimodal and revealed a clear dependence on physical activities and characteristics of the sports facilities. The use of climbing chalk in the gymnasium contributed significantly to the coarse mode. The average geometric mean diameter, geometric standard deviation and total number of coarse particles were 0.77 μm, 2.79 cm^?3 and 28 cm^?3, respectively.     

Distribution of PAHs and trace metals in urban stormwater sediments: combination of density fractionation,mineralogy and microanalysis

Sediment management from stormwater infiltration basins represents a real environmental and economic issue for stakeholders due to the pollution load and important tonnages of these by-products. To reduce the sediment volumes to treat, organic and metal micropollutant-bearing phases should be identified. A combination of density fractionation procedure and microanalysis techniques was used to evaluate the distribution of polycyclic aromatic hydrocarbons (PAHs) and trace metals (Cd, Cr, Cu, Ni, Pb, and Zn) within variable density fractions for three urban stormwater basin sediments. The results confirm that PAHs are found in the lightest fractions (d?d??3) whereas trace metals are equally distributed within the light, intermediary, and highest fractions (d?d?d?d?>?2.8 g cm^?3) and are mostly in the 2.3?d??3 fraction. The characterization of the five fractions by global analyses and microanalysis techniques (XRD and MEB-EDX) allowed us to identify pollutant-bearing phases. PAHs are bound to the organic matter (OM) and trace metals to OM, clays, carbonates and dense particles. Moreover, the microanalysis study underlines that OM is the main constituent responsible for the aggregation, particularly for microaggregation. In terms of sediment management, it was shown that density fractionation is not suitable for trace metals but could be adapted to separate PAH-enriched phases.     

Environmental effects of anticholinesterasic therapeutic drugs on a crustacean species,Daphnia magna

The presence of pharmaceutical drugs in the environment is an important field of toxicology, since such residues can cause deleterious effects on exposed biota. This study assessed the ecotoxicological acute and chronic effects of two anticholinesterasic drugs, neostigmine and pyridostigmine in Daphnia magna. Our study calculated 48 h-EC₅₀ values for the immobilization assay of 167.7 μg L^?1 for neostigmine and 91.3 μg L^?1 for pyridostigmine. In terms of feeding behavior, we calculated a 5 h-EC₅₀ for filtration rates of 7.1 and 0.2 μg L^?1 for neostigmine and pyridostigmine, respectively; for the ingestion rates, the calculated EC₅₀ values were, respectively, 7.5 and 0.2 μg L^?1 for neostigmine and pyridostigmine. In the reproduction assay, the most affected parameter was the somatic growth rate (LOECs of 21.0 and 2.9 μg L^?1 for neostigmine and pyridostigmine, respectively), followed by the fecundity (LOECs of 41.9 and 11.4 μg L^?1 for neostigmine and pyridostigmine, respectively). We also determined a 48 h-IC₅₀ for cholinesterase activity of 1.7 and 4.5 μg L^?1 for neostigmine and pyridostigmine, respectively. These results demonstrated that both compounds are potentially toxic for D. magna at concentrations in the order of the μg L^?1.     

Preliminary toxicological assessment of phthalate esters from drinking water consumed in Portugal

This paper reports, for the first time, the concentrations of selected phthalates in drinking water consumed in Portugal. The use of bottled water in Portugal has increased in recent years. The main material for bottles is polyethylene terephthalate (PET). Its plasticizer components can contaminate water by leaching, and several scientific studies have evidenced potential health risks of phthalates to humans of all ages. With water being one of the most essential elements to human health and because it is consumed by ingestion, the evaluation of drinking water quality, with respect to phthalate contents, is important. This study tested seven commercial brands of bottled water consumed in Portugal, six PET and one glass (the most consumed) bottled water. Furthermore, tap water from Lisbon and three small neighbor cities was analyzed. Phthalates (di-n-butyl phthalate ester (DnBP), bis(2-ethylhexyl) phthalate ester (DEHP), and di-i-butyl phthalate ester (DIBP)) in water samples were quantified (PET and glass) by means of direct immersion solid-phase microextraction and ionic liquid gas chromatography associated with flame ionization detection or mass spectrometry due to their high boiling points and water solubility. The method utilized in this study showed a linear range for target phthalates between 0.02 and 6.5 μg L^?1, good precision and low limits of detection that were between 0.01 and 0.06 μg L^?1, and quantitation between 0.04 and 0.19 μg L^?1. Only three phthalates were detected in Portuguese drinking waters: dibutyl (DnBP), diisobutyl (DIBP), and di(ethylhexyl) phthalate (DEHP). Concentrations ranged between 0.06 and 6.5 μg L^?1 for DnBP, between 0.02 and 0.16 μg L^?1 for DEHP, and between 0.1 and 1.89 μg L^?1 for DIBP. The concentration of DEHP was found to be up to five times higher in PET than in glass bottled water. Surprisingly, all the three phthalates were detected in glass bottled water with the amount of DnBP being higher (6.5 μg L^?1) than in PET bottled water. These concentrations do not represent direct risk to human health. Regarding potable tap water, only DIBP and DEHP were detected. Two of the cities showed concentration of all three phthalates in their water below the limits of detection of the method. All the samples showed phthalate concentrations below 6 μg L^?1, the maximum admissible concentration in water established by the US Environmental Protection Agency. The concentrations measured in Portuguese bottled waters do not represent any risk for adult's health.