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1.
When studying the effect of mixtures of toxic substances on soil organisms, attention must be paid to peculiarities in exposure to mixtures as opposed to that of single toxicants. The fungicides carbendazim and iprodione compete in the adsorption to soil. The presence of iprodione reduced the adsorption of carbendazim by 30%, while carbendazim reduced the adsorption of iprodione by 70%. Iprodione had little effect on the transformation rate of carbendazim in soil. However, carbendazim retarded the transformation of iprodione in soil by 26%. The concentration of the fungicides in pore water was found to be substantially higher for mixtures than when a fungicide alone was present in the soil. The effect of the additional fungicide on the concentration is especially apparent in the period following the first 1 to 2 weeks of the incubation. The inclusion of copper in the mixture has little additional effect on the concentration of the fungicides in pore water.  相似文献   

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Atmospheric gaseous elemental mercury [GEM] at 1.8, 4, and 59 m above ground, in parking lots, and in indoor and outdoor air was measured in Toronto City, Canada from May 2008-July 2009. The average GEM value at 1.8 m was 1.89 ± 0.62 ng m(-3). The GEM values increased with elevation. The average GEM in underground parking lots ranged from 1.37 to 7.86 ng m(-3) and was higher than those observed from the surface parking lots. The GEM in the indoor air ranged from 1.21 to 28.50 ng m(-3), was higher in the laboratories than in the offices, and was much higher than that in the outdoor air. All these indicate that buildings serve as sources of mercury to the urban atmosphere. More studies are needed to estimate the contribution of urban areas to the atmospheric mercury budget and the impact of indoor air on outdoor air quality and human health.  相似文献   

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Asaluyeh is one of the most heavily industrialised areas in the world where gas, petrochemical, and many downstream industries are located. This study aims to survey the biomonitoring of four metals and one metalloid in children living in the vicinity of Asaluyeh area. To do this, we analysed the creatinine-adjusted urinary levels of arsenic (As), cadmium (Cd), vanadium (V), manganese (Mn), and nickel (Ni) in 184 elementary schoolchildren (99 boys and 85 girls) living in Asaluyeh and compared them with a reference population. The comparisons were done for two seasons (spring and fall). The results showed that in the case area (Asaluyeh), the levels of As, V, Mn, and Ni were significantly higher and that of Cd was not significantly higher than the reference city for both seasons. The mean concentration of metal(loid)s in Asaluyeh (case) and Sadabad (reference) area as μg g?1 creatinine was As 2.90 and 2.24, V 0.06 and 0.03, Mn 0.28 and 0.25, Ni 0.54 and 0.29, and Cd 0.31 and 0.28 in spring and As 3.08 and 2.28, V 0.07 and 0.03, Mn 0.30 and 0.26, Ni 0.91 and 0.30, and Cd 0.36 and 0.31 in the fall. Seasonal variations played a key role in determining urinary metal(loid) concentration, as we saw the significant level of As, Cd, V, and Ni in fall than in spring. With regard to the impact of gender on the absorption and accumulation of urinary metal(loid)s, boys showed higher levels of the studied elements, especially for As, than girls as outdoor activities are more popular among boys. Due to the values being lower than those reported in literature, more research is needed on various population groups and other exposure sources in order to judge whether living in the vicinity of the gas and petrochemical industries in Asaluyeh is a threat to nearby residents.  相似文献   

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The Stone (limestone) and Marble (trade name) Industry (SMI) is one of the most important and active industries in Palestine, as being economically and financially rewarding and greatly beneficial to the public and private sectors. This industry, which employs about 15,000–20,000 workers, contributes 20–25% to the total industrial revenues of Palestine, and 4.5% to the total gross national product. Despite its benefits, SMI has adverse effects on public health, the environment, biodiversity, water systems (both surface and underground), green cover, and ecosystems in general, as it is considered one of the most air- water-, soil-, and noise-polluting sources. To achieve the purpose of this research paper, available data and literature are analyzed, evaluated, and used, in order to provide a comprehensive understanding of the status of SMI, in light of sustainable development. This relates to various perspectives, including limestone geology, geopolitics, socioeconomics, culture, technology, legislation, as well as climate change, acid rain, and harmful effects of the SMI scale on public health and safety, environmental well-being, and challenges facing the industry. Two field studies, carried out in northern and southern West Bank, dealing with particulate matter (PM1, PM2.5, PM7, PM10, and TSP) and environmental pollution, were analyzed, and their results were compared with each other, as well as with the World Health Organization’s (WHO) guidelines. It is found that both West Bank’s areas are heavily polluted, resulting in considerable adverse impacts on public health, the environment, and green cover. Based on the findings of this paper, it is recommended that SMI should properly adhere to WHO guidelines and international standards to make the industry safer and more durable and sustainable, with fewer negative impacts on public health, the environment, and green cover.

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The aim of the study was to evaluate the content, occurrence, and leachability of arsenic (As), lead (Pb), and thallium (Tl) in wastes from coal cleaning processes with respect to the safe management of this waste. The study focused on wastes resulting from the wet gravitation and flotation processes employed for the purposes of coking coal cleaning in four coal mines situated in the Upper Silesian Coal Basin (Poland). The scope of the study included (i) determination of the content of these elements in the investigated wastes using atomic absorption spectrometry, (ii) evaluation of their mode of occurrence using electron microprobe analysis, and (iii) preliminary assessment of their leachability in deionized water. The content of the analyzed elements in the examined samples of coal waste was twice as high as the average content of these elements in the Earth’s crust. The contents of As and Pb, however, did not exceed their permissible contents in inert waste in accordance with Polish legal regulations based on EU directives. The limit on the content of Tl is not specified by these regulations, but its amount in the examined samples was similar to that occurring in the soils. Moreover, leaching tests have shown that these elements are hardly eluted from the analyzed material. Their content in the water leachates was generally lower than the detection limit of the analytical method, complying with the standards for good and very good water quality. Low leachability of these elements most probably results from their mode of occurrence in the investigated wastes. The chemical analysis using an electron microprobe and the analysis of the correlation between these elements, e.g., total and pyritic sulfur, have shown that Pb, As, and Tl are mainly found in sulfide minerals which are characterized by negligible solubility. In conclusion, the investigated hard coal processing waste does not constitute a threat to the environment and can be commercially used or safely neutralized, e.g., by landfilling.

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Lead concentrations were determined in the organs of a shorebird, the dunlin, in its main invertebrate prey, and in sediments collected from five sites in the Bristol Channel. The highest sediment concentrations were found in the Taff Estuary (97 microg g(-1) dry mass). The highest concentrations in invertebrates were found in the upper Severn Estuary (45 microg g(-1) dry mass in Nereis diversicolor). In dunlins, the highest concentrations were found in the sternum (25 microg g(-1) dry mass in males), followed by the beak, legs, kidney, liver and pectoral muscle. Adult males contained significantly higher concentrations (ca 20%) than adult females, and in some cases adults had significantly higher concentrations than first year birds (36% higher in the case of the sternum). Lead concentrations tended to increase throughout the winter, being 37-115% higher in the spring. Birds were able to purge themselves of a substantial portion of their body lead burdens, probably during the autumn moult.  相似文献   

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Purpose  

This study was designed to assess the fate and the overall potential impacts of the widely prescribed drugs ranitidine and tramadol after their introduction into the aquatic environment.  相似文献   

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The occurrence, distribution, and risk assessment of antibiotics in freshwater systems are receiving global attention, because of their impact on the environment and human health. However, few studies have focused on this topic in Northeast China and its Songhua River, the third-largest river in China. This study investigated the occurrence and distribution of 12 antibiotics, including three cephalosporins (cefazolin, cefmetazole, cefotaxime), three macrolides (azithromycin, clarithromycin, roxithromycin), three fluoroquinolones (ofloxacin, norfloxacin, flumequine), and three sulfonamides (sulfadiazine, sulfapyridine, sulfamethoxazole) in the mainstream and tributaries of the Songhua River. A total of 152 surface water samples were collected in January, May, July, and October 2016. These samples were analyzed using solid-phase extraction (SPE) and ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The results indicated the wide use of all 12 antibiotics in the mainstream of the Songhua River. Sulfamethoxazole and cefazolin were the dominant antibiotics, with maximum concentrations of 73.1 and 65.4 ng L?1, respectively. Other antibiotics were present at mean concentrations below 15 ng L?1, except cefmetazole, present at a mean concentration of 35.6 ng L?1. The spatial distribution of antibiotics showed that unbalanced regional development may lead to the distribution pattern of the antibiotics in the tributaries and the mainstream. Thus study also assessed the seasonal variation of antibiotics in urban surface water; cephalosporin, sulfonamide, fluoroquinolone, and macrolide concentrations were significantly higher during the icebound season than during non-icebound season. This may be due to the low temperature and water flow of the river in winter. Risk assessment showed that azithromycin, clarithromycin, roxithromycin, flumequine, and sulfamethoxazole posed a low or median risk to the aquatic organisms in the mainstream. The potential risks created by antibiotics to the aquatic environment should not be neglected in the Songhua River. The potential risks created by antibiotics to the aquatic environment should not be neglected in the Songhua River.

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The Microtox® test, using the prokaryote Vibrio fischeri, was employed to assess the toxicity of the maize herbicides S-metolachlor, benoxacor, mesotrione and nicosulfuron, and their formulated compounds: Dual Gold Safeneur®, Callisto® and Milagro®; alone and in mixtures. For each compound we obtained original IC50 values, with consistent higher toxicities for formulated compounds compared to active ingredients alone. Mixtures of the four herbicides, prepared according to application doses encountered in agriculture, were found to be toxic at a lower concentration than single molecules. Mesotrione and nicosulfuron mixture appeared to be highly toxic to V. fischeri, however, this recommended post-emergence combination for maize crops got its toxicity decreased in formulated compound mixtures, suggesting that chemical interactions could potentially reduce the toxicity. Data comparisons to theoretical models showed a good prediction of mixture toxicity by Concentration Addition concept. Results seemed to exclude any synergistic effects on V. fischeri for the tested herbicide mixtures. Additional work coupling these bioassay data to ecosystemic level studies (aquatic and soil compartments) and data on additives and degradation products toxicity, will help to fill the gap in our knowledge of the environmental impact of these xenobiotics and in the choice of a more sustainable use of pesticides.  相似文献   

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Hakk H  Larsen G  Feil V 《Chemosphere》2001,42(8):975-983
A tissue distribution, excretion, and metabolism study was conducted using a relatively non-toxic dioxin congener, i.e., 1,2,7,8-tetrachlorodibenzo-p-dioxin (1278-TCDD), to gain a better understanding of mammalian metabolism of dioxins. Conventional, bile duct cannulated, and germ free male rats were administered mg/kg quantities as a single oral dose. Elimination of 1278-TCDD was largely complete by 72 h. Distribution of [14C]1278-TCDD was low in all tissues examined. Metabolites were identified in urine, bile, and feces by negative ion FAB-MS and 1H-NMR, or GC/MS. The major fecal metabolite was a NIH-shifted hydroxylated TCDD. The bile contained a glucuronide conjugate of this hydroxy TCDD, and a diglucuronide conjugate of a dihydroxy-triCDD. The major metabolites in urine were glucuronide and sulfate conjugates of 4,5-dichlorocatechol.  相似文献   

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The concentrations of Cd, Pb, Zn and Ni were measured in the leaves of 7 species of deciduous trees, from the urban sites of Istanbul, in both the Spring and Autumn seasons. We detected some differences in the heavy metal concentrations of the control and urban site samples of identical species. Highest concentrations of Cd were detected in Populus, Pb in Aesculus and Robinia, Zn in Populus, and Ni in Robinia and Fraxinus. Lowest chlorophyll content and highest peroxidase (POD) activity was found in the urban site samples of Acer. We have found a positive correlation between the increase in the POD activity and the Pb concentration in Populus. Generally, the tree species investigated in this study, are considered to have different tolerance levels to heavy metal pollution. The data obtained show that the chlorophyll content and the POD activity may be used as heavy metal stress biomarkers in the urban trees.  相似文献   

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This report summarizes data and conclusions from a one-year, interstate air quality study conducted in 1962 in the vicinity of Lewiston, Idaho, and Clarkston, Wash.1, 6, 7 The sampling and analyses techniques were selected to permit differentiation between possible sources and types of air pollutants.  相似文献   

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Jiang L  Hu X  Yin D  Zhang H  Yu Z 《Chemosphere》2011,82(6):822-828
Water samples were collected from 19 sampling sites along the Huangpu River in June and December 2009. The occurrence, distribution and seasonal variation of 22 antibiotics, including four tetracyclines, three chloramphenicols, two macrolides, six fluoroquinolones, six sulfonamides and trimethoprim were investigated. It was found that all 19 sampling sites were contaminated by antibiotics. Four antibiotics (sulfamerazine, norfloxacin, fleroxacin and sarafloxacin) were not detected. The detection frequencies of the other 18 antibiotics were in the range of 5.3-100%. The median concentrations of the detected antibiotics ranged from quantification limits to 36.71 ng L−1 (tetracycline) in June and to 313.44 ng L−1 (sulfamethazine) in December. The number of detected antibiotics and the overall antibiotic concentrations were higher in December than in June due to the different river flow conditions. Different dominant antibiotics were observed for each group of antibiotics between June and December. Higher total concentrations of veterinary antibiotics such as tetracyclines were observed in suburban sampling sites than in unban sites, indicating the role of livestock and agricultural activities as an important source of antibiotic contamination.  相似文献   

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