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Analysis of predictors related to soil contamination in recreational areas of Romania Texte intégral
2015
Gagiu, C. | Pica, E. M. | Querol, X. | Botezan, C S
Soil contamination in recreational areas can considerably affect children’s health, as they are the segment of the population most sensitive to anthropogenic contamination. Soil contamination in recreational areas is influenced by a number of factors such as type and age of the recreational area, nearby traffic intensity, proximity to industrial areas, presence of vegetation, level of usage, treated wood structures, and the extent of maintenance operations carried out in the area. These can most often be observed during a simple site visit. The purpose of the present research is to analyze to which extent the presence of these factors can trigger an alarm signal, highlighting soil contamination in urban recreational areas. In this regard, soil contamination was scaled using the integrated pollution index applied on nine distinctive contaminants (As, Cu, Cd, Zn, Pb, Hg, Co, Ni, Mg) identified using inductively coupled plasma mass spectrometry (ICP-MS). Multiple linear regression analysis was performed in order to assess predictors of soil contamination. The research was carried out in a number of 88 recreational areas, parks, and playgrounds from 19 Romanian cities, revealing the fact that proximity to industrial areas and intensive traffic had statistically significant effects on soil contamination. Furthermore, it was observed that in 78 out of the 88 analyzed locations, the concentrations of contaminants exceeded the guidelines established through national legislation, thus confirming the presumption that high concentrations of contaminants exist in the parks and playgrounds of Romania.
Afficher plus [+] Moins [-]Dynamic water quality modelling and uncertainty analysis of phytoplankton and nutrient cycles for the upper South Saskatchewan River Texte intégral
2015
Akomeah, Eric | Chun, Kwok Pan | Lindenschmidt, Karl-Erich
The surface water quality of the upper South Saskatchewan River was modelled using Water Quality Analysis Simulation Program (WASP) 7.52. Model calibration and validation were based on samples taken from four long-term water quality stations during the period 2007–2009. Parametric sensitivities in winter and summer were examined using root mean square error (RMSE) and relative entropy. The calibration and validation results show good agreement between model prediction and observed data. The two sensitivity methods confirmed pronounced parametric sensitivity to model state variables in summer compared to winter. Of the 24 parameters examined, dissolved oxygen (DO) and ammonia (NH₃-N) are the most influenced variables in summer. Instream kinetic processes including nitrification, nutrient uptake by algae and algae respiration induce a higher sensitivity on DO in summer than in winter. Moreover, in summer, soluble reactive phosphorus (SRP) and chlorophyll-a (Chla) variables are more sensitive to algal processes (nutrient uptake and algae death). In winter however, there exists some degree of sensitivity of algal processes (algae respiration and nutrient uptake) to DO and NH₃-N. Results of this study provide information on the state of the river water quality which impacts Lake Diefenbaker and the need for additional continuous monitoring in the river. The results of the sensitivity analysis also provide guidance on most sensitive parameters and kinetic processes that affect eutrophication for preliminary surface water quality modelling studies in cold regions.
Afficher plus [+] Moins [-]Mercurial exposure of residents of Santarém and Oriximiná cities (Pará, Brazil) through fish consumption Texte intégral
2015
Bourdineaud, Jean-Paul | Durrieu, Gilles | Sarrazin, Sandra Layse Ferreira | da Silva, Wânia Cristina Rodrigues | Mourão, Rosa Helena Veras | de Oliveira, Ricardo Bezerra
A survey of the mercurial exposure of residents of Santarém and Oriximiná showed a differential mercurial impregnation between men and women. At the level of both cities, the mean hair mercury concentrations were 1.5 ± 0.5 (90th and 95th percentiles: 2.8 and 4.3) and 2.52 ± 0.09 μg g Hg/g (90th and 95th percentiles: 4.7 and 8.1) for women and men, respectively. The mercurial contamination appeared significantly closely linked to the daily amount of consumed fish. Carnivore species pescada branca (Plagioscion squamosissimus) and apapá (Pellona castelnaeana) and non-carnivore species pacú (Mylossoma duriventre) and aracú (Schizodon fasciatus) were consumed by 22, 19, 55 and 25 % of people, respectively, and the mean mercury concentrations within fish flesh were 1.44 ± 0.11, 1.66 ± 0.19, 0.48 ± 0.09 and 0.49 ± 0.06 μg/g dry weight, respectively. Men aged above 35 were significantly more contaminated than those below. The mean hair concentrations of men were 5.20 ± 1.25 and 1.50 ± 0.22 μg/g, for those aged above 35 and below, respectively. The probability for women of childbearing age from both cities to present a hair mercury concentration above 1 μg Hg/g (corresponding to the US Environmental Protection Agency reference dose) was equal to 0.30 (95 % confidence interval of 0.24–0.36). The probability of hair mercury concentration to be above the lowest observable adverse effect level (LOAEL) (0.3 μg Hg/g) was equal to 0.79 (95 % confidence interval: 0.73–0.86).
Afficher plus [+] Moins [-]Variation of levels and distribution of N-nitrosamines in different seasons in drinking waters of East China Texte intégral
2015
Li, Ting | Yu, Dian | Xian, Qiming | Li, Aimin | Sun, Cheng
We surveyed the occurrence of nine N-nitrosamine species in ten bottled drinking waters from supermarket and other water samples including raw waters, finished waters, and distribution system waters from nine municipal drinking water treatment plants in eight cities of Jiangsu Province, East China. N-nitrosodimethylamine (NDMA) was detected in one of ten bottled drinking water samples at concentration of 4.8 ng/L and N-nitrosomorpholine (NMor) was detected in four of the ten bottles with an average concentration and a standard deviation of 16 ± 15 ng/L. The levels of nitrosamines in the distribution system water samples collected during summer season ranged from below detection limit (BDL) to 5.4 ng/L for NDMA, BDL to 9.5 ng/L for N-nitrosomethylethylamine (NMEA), BDL to 2.7 ng/L for N-nitrosodiethylamine (NDEA) and BDL to 8.5 ng/L for N-nitrosopyrrolidine (NPyr). Samples of distribution system waters collected in winter season had levels of nitrosamines ranged from BDL to 45 ng/L for NDMA, BDL to 5.2 ng/L for NPyr, and BDL to 309 ng/L for N-nitrosopiperidine (NPip). A positive correlation of the concentration of NDMA as well as the total nine N-nitrosamines between finished waters and distribution system waters was observed. Both dissolved organic carbon and nitrite were found to correlate linearly with N-nitrosamine levels in raw waters.
Afficher plus [+] Moins [-]PFOS and PFOA in paired urine and blood from general adults and pregnant women: assessment of urinary elimination Texte intégral
2015
Zhang, Tao | Sun, Hongwen | Qin, Xiaolei | Gan, Zhiwei | Kannan, Kurunthachalam
Although levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in human blood are well documented, information on elimination of these chemicals is limited. In this study, PFOS and PFOA were analyzed in 81 whole blood–urine paired samples from general adults and pregnant women in Tianjin, China. PFOS and PFOA were detected in 48 and 76 % of adult urine (AU) samples, with geometric mean (GM) concentrations of 0.011 and 0.008 ng/mL, respectively; whereas relatively low PFOS and PFOA concentrations were found in maternal urine (MU) samples, with GM concentrations of 0.006 and 0.003 ng/mL, respectively. For PFOA, the coefficients of Pearson’s correlation between whole blood concentrations and creatinine-adjusted and creatinine-unadjusted urinary concentrations were 0.348 (p = 0.013) and 0.417 (p = 0.002), respectively. The GM urinary elimination rates of PFOS (PFOSUER) and PFOA (PFOAUER) were 16 and 25 %, respectively, for adults. These results indicate that urine is an important pathway of excretion of perfluoroalkyl substances (PFASs). The partitioning ratios of PFAS concentration between urine and whole blood (PFASU/B) in pregnant women (PFOSU/B, 0.0004; PFOAU/B, 0.0011) were significantly lower (p = 0.025 for PFOSU/B, p = 0.017 for PFOAU/B) than the ratios found in non-pregnant women (PFOSU/B, 0.0013; PFOAU/B, 0.0028). Furthermore, our results suggest a clear gender difference in the urinary elimination of PFOA, with male adults (31 %) having significantly higher PFOAUERthan that of female adults (19 %). PFOSUERwas significantly inversely correlated with age (r = −0.334, p = 0.015); these findings suggest that urinary elimination of PFOS is faster in young adults than in the elderly.
Afficher plus [+] Moins [-]Toxic metals in topsoil under different land uses from Xiandao District, middle China: distribution, relationship with soil characteristics, and health risk assessment Texte intégral
2015
Li, Fei | Huang, Jinhui | Zeng, Guangming | Liu, Wenchu | Huang, Xiaolong | Huang, Bin | Ku, Yenlin | Shi, Lixiu | He, Xiaoxiao | He, Yan
To explore mutual relationship among soil characteristics (soil organic matter, soil texture, cation exchange capacity, and pH), land uses, toxic metal (As, Hg, Mn, and Ni) distributions and induced health risk, 156 topsoil samples (0–20 cm) were collected from farm land, forest land and construction land in a grid pattern throughout Xiandao District. Compared with Hunan soil background values, the elevated concentrations of As, Hg and Ni were found to different extent. Pearson correlation matrix suggested As-silt, Mn-Ni, CEC-Mn, CEC-Ni, and CEC-pH had significantly positive correlation, and significantly negative correlation existed in SOM-pH, CEC-clay, SOM-Ni, and SOM-pH. Results based on the soil texture analysis, analysis of variance, and Tukey test indicated the concentrations of As and Ni were higher in relatively fine textures, and the mean contents of As, Mn, Ni, pH, and SOM in construction land, construction land, construction land, forest land, and construction land, respectively, were with the significant difference from that in the other two land uses. For non-carcinogenic effects, Hazard Indexes (HIs) of Ni, Hg, Mn, and As decreased in the order of As > Hg > Mn > Ni to both children and adults. Risk contributions of each exposure pathway decreased in the order of ingestion > dermal contact > inhalation of resuspended particles for HIAₛ, HIMₙ, and HINᵢ. The inhalation of vapors was the highest contributor for HIHg, followed by ingestion, dermal contact, and inhalation of resuspended particles. As and Hg were regarded as the priority pollutants. The hierarchical risk areas were identified after comprehensive consideration of local residential population density distribution, and the different risk management measures were finally suggested for the different priority areas.
Afficher plus [+] Moins [-]Changes of benthic bacteria and meiofauna assemblages during bio-treatments of anthracene-contaminated sediments from Bizerta lagoon (Tunisia) Texte intégral
2015
Ben Said, Olfa | Louati, Hela | Soltani, Amel | Preud’homme, Hugues | Cravo-Laureau, Cristiana | Got, Patrice | Pringault, Olivier | Aissa, Patricia | Duran, Robert
Sediments from Bizerta lagoon were used in an experimental microcosm setup involving three scenarios for the bioremediation of anthracene-polluted sediments, namely bioaugmentation, biostimulation, and a combination of both bioaugmentation and biostimulation. In order to investigate the effect of the biotreatments on the benthic biosphere, 16S rRNA gene-based T-RFLP bacterial community structure and the abundance and diversity of the meiofauna were determined throughout the experiment period. Addition of fresh anthracene drastically reduced the benthic bacterial and meiofaunal abundances. The treatment combining biostimulation and bioaugmentation was most efficient in eliminating anthracene, resulting in a less toxic sedimentary environment, which restored meiofaunal abundance and diversity. Furthermore, canonical correspondence analysis showed that the biostimulation treatment promoted a bacterial community favorable to the development of nematodes while the treatment combining biostimulation and bioaugmentation resulted in a bacterial community that advantaged the development of the other meiofauna taxa (copepods, oligochaetes, polychaetes, and other) restoring thus the meiofaunal structure. The results highlight the importance to take into account the bacteria/meiofauna interactions during the implementation of bioremediation treatment.
Afficher plus [+] Moins [-]Concentrations, bioaccumulation, and human health risk assessment of organochlorine pesticides and heavy metals in edible fish from Wuhan, China Texte intégral
2015
Cui, Lili | Ge, Jing | Zhu, Yindi | Yang, Yuyi | Wang, Jun
The objective of this study was to determine concentration and bioaccumulation of organochlorine pesticides and heavy metals in edible fish from Wuhan, China, in order to assess health risk to the human via fish consumption. Two edible fish species (Aristichthys nobilis and Hypophthalmichthys molitrix) were collected and analyzed for 11 organochlorine pesticides (OCPs) and eight heavy metals (HMs). Concentrations of ∑HCHs, ∑DDTs, and ∑OCPs in fish samples were in the range of 0.37–111.20, not detected (nd)–123.61, and 2.04–189.04 ng g⁻¹ (wet weight), respectively. Bioaccumulation factors (BAFs) of OCPs in bighead carp (A. nobilis) were higher than those in silver carp (H. molitrix). Concentrations of ∑HMs in bighead carp and silver carp were 352.48 and 345.20 mg kg⁻¹ (dw), respectively. Daily exposure of OCPs and HMs for consumers was estimated by comparing estimated daily intake (EDI) with different criteria. The results revealed that the EDIs in our study were all lower than those criteria. Target hazard quotient (THQ) and risk ratio (R) were used to evaluate non-carcinogenic and carcinogenic risks, respectively. As regard to non-carcinogenic effects of the contaminants, hazard quotients (THQ) of OCPs and HMs were both lower than 1.0, implying negligible non-carcinogenic risk via fish consumption in study area. Nevertheless, in view of carcinogenic effects of the contaminants, the total value of risk ratio (R) of OCPs was lower than the threshold of tolerable risk while the total value of risk ratio (R) of HMs was higher than the threshold of tolerable risk due to the high carcinogenic risk ratios of As and Cr, indicating high carcinogenic risks via fish consumption. The results demonstrated that HMs in edible fish from Wuhan, China, especially As and Cr required more attention than OCPs.
Afficher plus [+] Moins [-]Numerical study of a buoyant plume from a multi-flue stack into a variable temperature gradient atmosphere Texte intégral
2015
Velamati, Ratna Kishore | Vivek, M. | Goutham, K. | Sreekanth, G. R. | Dharmarajan, Santosh | Goel, Mukesh
Air pollution is one of the major global hazards and industries have been one of its major contributors. This paper primarily focuses on analyzing the dispersion characteristics of buoyant plumes of the pollutant released from a multi-flue vertical stack into a variable temperature gradient atmosphere (α) in a constant-velocity cross wind using two stack configurations—inline and parallel. The study is conducted for different Froude numbers, Fr = 12.64, 9.55, and 8.27. The atmospheric temperature gradients considered for the study are 0, +1, +1.5, and +2 K/100 m. The numerical study is done using the commercial computational fluid dynamics (CFD) code FLUENT. The effects of stack configuration, α, and Fr on the plume characteristics are presented. It is observed that the plume rises higher and disperses over a larger area with the inline configuration due to better mixing and shielding effect. With higher α, it is seen that the plume rises initially and then descends due to variation of the buoyant force. The plume rise initially is strongly influenced by the momentum of the jet, and as it moves downstream, it is influenced by the cooling rate of the plume. Furthermore, the plume rises higher and disperses over a larger area with a decrease in Fr.
Afficher plus [+] Moins [-]Stable sulfur isotope ratios and water-soluble inorganic compositions of PM10 in Yichang City, central China Texte intégral
2015
Yang, Zhou | Li, Xiao-Dong | Deng, Jie | Wang, Haiyun
Chemical and sulfate-sulfur isotopic compositions of water-soluble inorganic ions were analyzed for aerosol sample particulate matter with aerodynamic diameter ≤10 μm (PM₁₀) collected during 17–28 December 2012 at Yichang City, Hubei Province, central China. Most water-soluble inorganic ions, except for NO₃ ⁻ and NH₄ ⁺, showed slightly higher concentration in daytime than in nighttime, and the major detected ions followed the order of SO₄ ²⁻ > NO₃ ⁻ > Ca²⁺ > Na⁺ > NH₄ ⁺ > Cl⁻ in daytime and nighttime, of which SO₄ ²⁻ is the most abundant ionic component that accounted for about 49.1 and 49.3 % of the total mass of analyzed ions in daytime and nighttime, respectively. According to the correlation coefficients among the mass concentrations of water-soluble inorganic ions, there may mainly exist in forms of (NH₄)₂SO₄ and NH₄NO₃ in daytime and NH₄NO₃ in nighttime. The δ³⁴S values of sulfate ranged from +2.82 to +4.63 ‰ (average +3.97 ‰) in daytime and from +2.90 to +5.39 ‰ (average +4.08 ‰) in nighttime, indicating that the source of sulfate in PM₁₀ was mainly derived from coal burning (δ³⁴S, +3.68 ‰) in Yichang City. The [NO₃ ⁻]/[SO₄ ²⁻] mass ratio varied between 0.2 and 0.6 with an average of 0.4 in daytime and 0.1 to 0.8 with an average of 0.4 in nighttime, which implying that the stationary source emissions would be more important than the vehicle emissions in the studied area. As a whole, the mixture of coal burning, vehicle exhaust, and resuspended road dust would be responsible for the sources of PM₁₀ in Yichang City during wintertime.
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