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Occurrence and risk assessment of selected phthalates in drinking water from waterworks in China Full text
2015
Liu, Xiaowei | Shi, Jianghong | Bo, Ting | Li, Huiyuan | Crittenden, John C.
The first nationwide survey of six phthalates (diethyl phthalate (DEP); dimethyl phthalate (DMP); di-n-butyl phthalate (DBP); butyl benzyl phthalate (BBP); bis(2-ethylhexyl) phthalate (DEHP); din-octyl phthalate (DnOP)) in drinking waters from waterworks was conducted across seven geographical zones in China. Of the six target phthalates, DBP and DEHP were the highest abundant phthalates with median (± interquartile range) values of 0.18 ± 0.47 and 0.18 ± 0.97 μg/L, respectively, but did not exceed the limit values in China’s Standards for Drinking Water Quality. These phthalates in drinking water were generally higher in the northern regions of China than those in the southern and eastern regions. Based on the investigated concentrations, lifetime exposure risk assessment indicated that phthalates in drinking water did not pose carcinogenic and noncarcinogenic risks to Chinese residents, even under the conservative scenario (with 95th percentile risk). In addition, we found that DEHP contributed the greatest risk to the total exposure risk of all the selected phthalates and oral ingestion was the main exposure route for phthalates in drinking water.
Show more [+] Less [-]Copper, zinc and lead biogeochemistry in aquatic and land plants from the Iberian Pyrite Belt (Portugal) and north of Morocco mining areas Full text
2015
Durães, Nuno | Bobos, Iuliu | Ferreira da Silva, Eduardo | Dekayir, Abdelilah
The ability of aquatic (Juncus effusus L., Scirpus holoschoenus L., Thypha latifolia L. and Juncus sp.) and land (Cistus ladanifer L., Erica andevalensis C.-R., Nerium oleander L., Isatis tinctoria L., Rosmarinus officinalis L., Cynodon dactylon L. and Hordeum murinum L.) plants from Portugal (Aljustrel, Lousal and São Domingos) and Morocco (Tighza and Zeida) mining areas to uptake, translocate and tolerate heavy metals (Cu, Zn and Pb) was evaluated. The soils (rhizosphere) of the first mining area are characterized by high acidity conditions (pH 2–5), whereas from the second area, by alkaline conditions (pH 7.0–8.5). Physicochemical parameters and mineralogy of the rhizosphere were determined from both areas. Chemical analysis of plants and the rhizosphere was carried out by inductively coupled plasma emission spectrometry. The sequential chemical extraction procedure was applied for rhizosphere samples collected from both mining areas. In the acid conditions, the aquatic plants show a high capacity for Zn bioaccumulation and translocation and less for Pb, reflecting the following metal mobility sequence: Zn > Cu > Pb. Kaolinite detected in the roots by infrared spectroscopy (IR) contributed to metal fixation (i.e. Cu), reducing its translocation to the aerial parts. Lead identified in the roots of land plants (e.g. E. andevalensis) was probably adsorbed by C–H functional groups identified by IR, being easily translocated to the aerial parts. It was found that aquatic plants are more efficient for phytostabilization than bioaccumulation. Lead is more bioavailable in the rhizosphere from Morocco mining areas due to scarcity of minerals with high adsorption ability, being absorbed and translocated by both aquatic and land plants.
Show more [+] Less [-]United States National Sewage Sludge Repository at Arizona State University—a new resource and research tool for environmental scientists, engineers, and epidemiologists Full text
2015
Venkatesan, Arjun K. | Done, Hansa Y. | Halden, Rolf U.
Processed municipal sewage sludges (MSS) are an abundant, unwanted by-product of wastewater treatment, increasingly applied to agriculture and forestry for inexpensive disposal and soil conditioning. Due to their high organic carbon and lipid contents, MSS not only is rich in carbon and nutrients but also represents a “sink” for recalcitrant, hydrophobic, and potentially bioaccumulative compounds. Indeed, many organics sequestered and concentrated in MSS meet the US Environmental Protection Agency’s definition of being persistent, bioaccumulative, and toxic (PBT). In a strategic effort, our research team at the Biodesign Institute has created the National Sewage Sludge Repository (NSSR), a large repository of digested MSSs from 164 wastewater treatment plants from across the USA, as part of the Human Health Observatory (H2O) at Arizona State University (ASU). The NSSR likely represents the largest archive of digested MSS specimens in the USA. The present study summarizes key findings gleaned thus far from analysis of NSSR samples. For example, we evaluated the content of toxicants in MSS and computed estimates of nationwide inventories of mass produced chemicals that become sequestrated in sludge and later are released into the environment during sludge disposal on land. Ongoing efforts document co-occurrence of a variety of PBT compounds in both MSS and human samples, while also identifying a large number of potentially harmful MSS constituents for which human exposure data are still lacking. Finally, we summarize future opportunities and invite collaborative use of the NSSR by the research community. The H2O at ASU represents a new resource and research tool for environmental scientists and the larger research community. As illustrated in this work, this repository can serve to (i) identify and prioritize emerging contaminants, (ii) provide spatial and temporal trends of contaminants, (iii) inform and evaluate the effectiveness of environmental policy-making and regulations, and (iv) approximate, ongoing exposures and body burdens of mass-produced chemicals in human society.
Show more [+] Less [-]Oxidation of diclofenac with chlorine dioxide in aquatic environments: influences of different nitrogenous species Full text
2015
Wang, Yingling | Liu, Haijin | Liu, Guoguang | Xie, Youhai | Ni, Tianjun
The oxidation of diclofenac (DCF), a non-steroidal anti-inflammatory drug and emerging water pollutant, with chlorine dioxide was investigated under simulated water disinfection conditions. The reaction kinetics as functions of the initial concentrations of DCF, different nitrogenous species, and different pE values were experimentally determined. The results demonstrated that DCF reacted rapidly with ClO₂, where more than 75 % of DCF (≤3.00 μM) was removed by 18.94 μM ClO₂ within 60 s. All of the reactions followed pseudo first-order kinetics with respect to DCF, and the rate constant, k ₒbₛ, exhibited a significant decrease from 4.21 × 10⁻² to 8.09 × 10⁻³ s⁻¹, as the initial DCF concentration was increased from 1.00 to 5.00 μM. Furthermore, the degradation kinetics of DCF was clearly dependent on nitrogen-containing ion concentrations in the reaction solution. Ammonium and nitrite ions inhibited the DCF degradation by ClO₂, whereas nitrate ion clearly initiated its promotion. In contrast, the inhibitory effect of NO₂ ⁻ was more robust than that of NH₄ ⁺. When the values of pE were gradually increased, the transformation of NH₄ ⁺ to NO₂ ⁻, and subsequently to NO₃ ⁻, would occur, the rate constants were initially decreased, and then increased. When NH₄ ⁺ and NO₂ ⁻ coexisted, the inhibitory effect on the DCF degradation was less than the sum of the partial inhibitory effect. However, when NO₂ ⁻ and NO₃ ⁻ coexisted, the actual inhibition rate was greater than the theoretical estimate. These results indicated that the interaction of NH₄ ⁺ and NO₂ ⁻ was antagonistic, while the coexistence of NO₂ ⁻ and NO₃ ⁻ was observed to have a synergistic effect in aqueous environments.
Show more [+] Less [-]A preliminary assessment of the potential of using an acacia—biochar system for spent mine site rehabilitation Full text
2015
Reverchon, Frédérique | Yang, Hong | Ho, Thian Yuan | Yan, Guijun | Wang, Jian | Xu, Zhihong | Chen, Chengrong | Zhang, Dongke
Mining activities result in extensive soil degradation by removing the top soil, disturbing soil structure and altering microbial communities. Rehabilitation of spent mine sites through revegetation thus requires proper soil amendments. In this study, a pot trial was conducted to investigate the effects of a jarrah biochar on the growth and nutrient status of a native legume, Acacia tetragonophylla, grown in a mixture of topsoil and mine rejects. Two biochar application rates (37 and 74 t ha⁻¹) and two types of biochar, namely nutrient-enriched and non-enriched, were tested. We measured the soil pH and electrical conductivity, the carbon (C) and nitrogen (N) contents and C and N isotope composition (δ¹³C and δ¹⁵N) of soil and plants, the foliar phosphorus content and the growth and leaf biomass of the plants. Whilst no significant effect of biochar was observed on plant growth, biochar amendment affected soil properties and plant nutritional status. The highest rate of biochar application increased soil pH, C content and C/N ratio, and decreased soil δ¹³C. Biochar application also enhanced photosynthetic N use efficiency, as showed by the increase in foliar C/N ratio, and biological N fixation rates, as indicated by foliar δ¹⁵N. These positive effects were not observed when biochar was nutrient-enriched due to the associated increase in soil N. Revegetation of mine sites with acacia in combination with biochar amendment constitutes a plausible alternative to the wide use of N fertiliser through the supply of additional N to the system, even though other nutrients may be required in order to enhance plant early growth.
Show more [+] Less [-]A margin of exposure approach to assessment of non-cancerous risk of diethyl phthalate based on human exposure from bottled water consumption Full text
2015
Zare Jeddi, Maryam | Rastkari, Noushin | Ahmadkhaniha, Reza | Yunesian, Masud | Nabizadeh, Ramin | Daryabeygi, Reza
Phthalates may be present in food due to their widespread presence as environmental contaminants or due to migration from food contact materials. Exposure to phthalates is considered to be potentially harmful to human health as well. Therefore, determining the main source of exposure is an important issue. So, the purpose of this study was (1) to measure the release of diethyl phthalate (DEP) in bottled water consumed in common storage conditions specially low temperature and freezing conditions; (2) to evaluate the intake of DEP from polyethylene terephthalate (PET) bottled water and health risk assessment; and (3) to assess the contribution of the bottled water to the DEP intake against the tolerable daily intake (TDI) values. DEP migration was investigated in six brands of PET-bottled water under different storage conditions room temperature, refrigerator temperature, freezing conditions (40 °C ,0 °C and −18 °C) and outdoor] at various time intervals by magnetic solid extraction (MSPE) using gas chromatography–mass spectroscopy (GC-MS). Eventually, a health risk assessment was conducted and the margin of exposure (MOE) was calculated. The results indicate that contact time with packaging and storage temperatures caused DEP to be released into water from PET bottles. But, when comprising the DEP concentration with initial level, the results demonstrated that the release of phthalates were not substantial in all storage conditions especially at low temperatures (<25 °C) and freezing conditions. The daily intake of DEP from bottled water was much lower than the reference value. However, the lowest MOE was estimated for high water consumers (preschooler > children > lactating women > teenagers > adults > pregnant women), but in all target groups, the MOE was much higher than 1000, thus, low risk is implied. Consequently, PET-bottled water is not a major source of human exposure to DEP and from this perspective is safe for consumption.
Show more [+] Less [-]Mechanisms of silicon-mediated alleviation of drought and salt stress in plants: a review Full text
2015
Rizwan, Muhammad | Ali, Shafaqat | Ibrahim, Muhammad | Farid, Mujahid | Adrees, Muhammad | Bharwana, Saima Aslam | Zia-ur-Rehman, Muhammad | Qayyum, Muhammad Farooq | Abbas, Farhat
Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na⁺ uptake and translocation while increased K⁺ uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils.
Show more [+] Less [-]The brown mussel Perna perna (L., 1758) as a sentinel species for chlorinated pesticide and dioxin-like compounds Full text
2015
Galvao, Petrus | Henkelmann, Bernhard | Longo, Renan | Torres, João Paulo Machado | Malm, Olaf | Schramm, Karl-Werner
To contribute to the use of the tropical brown mussel Perna perna as a sentinel species for organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB), the present study reports data on the toxicokinetics of these compounds in P. perna. Specifically, the authors present data on OCP and PCB bioaccumulation for eight sampling months from three bays (SE Brazil) and two transplant experiments (each 1 month long). Although seasonality is observed in the total lipid content of the whole soft tissue, with summer samples showing higher values, no such seasonality is observed in the OCP and PCB concentrations bioaccumulated by the mussel P. perna. Because no seasonal effect is observed in the annual OCP and PCB concentrations bioaccumulated by P. perna, the use of this species as a sentinel organism to monitor organochlorinated compounds is encouraged. One month of transplantation is not enough to allow the transplanted specimens to reach the concentrations observed in animals reared at the destination site. Nevertheless, P. perna showed a clear tendency to depurate the DDT metabolites p,p′-DDD and p,p′-DDE after 1 month of transplantation.
Show more [+] Less [-]Analysis of serum levels of 15 trace elements in breast cancer patients in Shandong, China Full text
2015
Ding, Xiao | Jiang, Meng | Jing, Haiyan | Sheng, Wei | Wang, Xingwen | Han, Junqing | Wang, Luhua
Experimental and epidemiological studies suggest that serum levels of trace elements may be associated with breast cancer risk. We compared serum levels of 15 trace elements between breast cancer patients and normal controls from Shandong, China, for the first time to assess whether serum levels of trace elements were associated with breast cancer risk. Eighty-eight breast cancer patients and 84 healthy controls were enrolled in the study. A Spectraspan V direct current plasma atomic emission spectrometer was used to determine the serum levels of 15 trace elements including Zn, Mn, Al, Cd, Fe, Mg, Ca, Pb, Cu, Se, Ni, Ti, Co, Li, and Cr. Breast cancer patients had significantly higher serum levels of Cd (p = 0.000), Mg (p = 0.001), Cu (p = 0.000), Co (p = 0.006), and Li (p = 0.003) and borderline higher Cr (p = 0.052), while significantly lower Mn (p = 0.000), Al (p = 0.000), Fe (p = 0.000), and Ti (p = 0.000) compared to their matched controls. However, there were no significant differences in serum levels of Zn (p = 0.824), Ca (p = 0.711), Pb (p = 0.274), Se (p = 0.236), and Ni (p = 0.185) between the two groups. Our study showed a possible association between serum levels of trace elements and breast cancer risk in eastern China, though it warrants further investigations to confirm the association. If confirmed, modulation of trace elements may help reduce breast cancer risk.
Show more [+] Less [-]Characterization of 241Pu occurrence, distribution, and bioaccumulation in seabirds from northern Eurasia Full text
2015
Strumińska-Parulska, Dagmara I. | Skwarzec, Bogdan
The paper presents unique data of plutonium²⁴¹Pu study in seabirds from northern Eurasia, permanently or temporally living at the southern Baltic Sea coast. Together, ten marine birds species were examined, as follows: three species that permanently reside at the southern Baltic, four species of wintering birds, and three species of migrating birds; 366 samples were analyzed. The obtained results indicated plutonium was non-uniformly distributed in organs and tissues of analyzed seabirds. The highest²⁴¹Pu content was found in the digestion organs and feathers, the lowest in muscles. Also, the internal radiation doses from²⁴¹Pu were evaluated.
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