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1.
Samples of precipitation events (snow and rain) in Dalian, a typical coastal town in China, were analyzed for perfluorosulfonates (PFSAs) and perfluorocarboxylates (PFCAs) to investigate atmospheric contamination by these compounds. In the snow event on December 16, 2006, samples were collected from 21 different sites and in another 6 precipitation events, samples were collected from a single location. Four PFSAs (C4, C6, C8, C10) and seven PFCAs (C6–12) were analyzed. Among the homologues, perfluorooctane sulfonate (PFOS) concentrations were the highest with a geometric mean (GM) of 145 ng/L (n = 21) during the snow event on December 16, 2006, followed by perfluorooctanoate (PFOA) with a GM of 24.7 ng/L (n = 21). Concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS) and perfluoroheptanoate (PFHpA) were more than two orders of magnitude lower than that of PFOS. Other PFSAs and PFCAs were found to be below the limit of detection in all the samples. In other 6 precipitation events, PFSAs and PFCAs were detected approximately in the same order of magnitude in both snow and rain. The results indicate that wet deposition may be a potential transport mechanism of perfluorinated chemicals in the environment.  相似文献   

2.
During Balkan conflicts in 1994-1995, depleted uranium (DU) ordnance was employed and was left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Bosnia and Herzegovina, radiological survey of DU in biological and water samples were carried out over the period 12-24 October 2002. The uranium isotopic concentrations in biological samples collected in Bosnia and Herzegovina, mainly lichens, mosses and barks, were found to be in the range of 0.27-35.7 Bq kg(-1) for (238)U, 0.24-16.8 Bq kg(-1) for (234)U, and 0.02-1.11 Bq kg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control site. Moreover, the (236)U in some of the samples was detectable. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at most sites examined, but in very low levels. The presence of DU in the biological samples was as a result of DU contamination in air. The uranium concentrations in water samples collected in Bosnia and Herzegovina were found to be in the range of 0.27-16.2 m Bq l(-1) for (238)U, 0.41-15.6 m Bq l(-1) for (234)U and 0.012-0.695 m Bq l(-1) for (235)U, and two water samples were observed to be DU positive; these values are much lower than those in mineral water found in central Italy and below the WHO guideline for public drinking water. From radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated sites in terms of possible DU contamination of water and/or plants.  相似文献   

3.
4.
110mAg, as a radionuclide of corrosion products in water-cooled nuclear reactors, was detected in the liquid effluents of Guangdong Daya Bay Nuclear Power Station (GNPS) of Daya Bay under normal operation conditions. Experiments on a simulated terrestrial agricultural ecosystem were carried out using the pot experiment approach. The most common plants in Hong Kong and the South China vegetable gardens such as lettuce, Chinese spinach, kale, carrot, pepper, eggplant, bean, flowering cabbage, celery, European onion and cucumber were selected for (110m)Ag root and foliar uptake tests. The results show that carrot, kale and flowering cabbage have the greatest values of soil to plant transfer factor among the vegetables, while(110m)Ag can be transferred to Chinese spinach via foliar uptake. Flowering cabbage, the most popular leafy vegetable locally, could be used as a biomonitor for the radioisotope contamination in vegetables. Soil column and adsorption tests were also carried out to study the leaching ability and distribution coefficient (K(d)) of (110m)Ag in the soil. The results show that most of the radionuclide was adsorbed in the top 1 cm of soil regardless of the pH value. The K(d) was also determined.  相似文献   

5.
Vulnerabilities to floods in Thailand are changing as a result of many factors. Formal and informal institutions help shape exposure, sensitivity and capacities to respond of individuals, social groups and social-ecological systems. In this paper we draw on several case studies of flood events and flood-affected communities to first assess how current practices reflect various laws, procedures, programs and policies for managing floods and disasters and then explore the implications for dealing with additional challenges posed by climate change. Our analysis identifies several institutional traps which need to be overcome if vulnerability is to be reduced, namely capture of agendas by technical elites, single-level or centralized concentration of capacities, organizational fragmentation and overemphasis on reactive crisis management. Possible responses are to expand public participation in managing risks, build adaptive capacities at multiple levels and link them, integrate flood disaster management and climate change adaptation into development planning, prioritize risk reduction for socially vulnerable groups and strengthen links between knowledge and practice. Responses like these could help reduce vulnerabilities under current climate and flood regimes, while also improving capacities to handle the future which every way that unfolds.  相似文献   

6.
Russian Journal of Ecology - The present study was conducted to investigate the n-alkane composition of typical alpine meadows. Plant and soil samples were collected and analyzed to characterize...  相似文献   

7.
Radon concentrations were measured in several locations in each of approximately 100 dwellings in central Maine and in Houston, TX. Integrated samples were taken during the heating (or cooling) seasons with commercially available passive alpha track devices, while grab samples were taken at the time of integrated sampler deployment. It was found that both indoor and outdoor measurements in both areas were distributed log normally, and that the geometric mean of indoor measurements in Maine was three times higher than that of corresponding measurements in the Houston area. It was also noted that the mean of the indoor grab sample measurements was not significantly different from the mean of the indoor integrated measurements, and that the degree of correlation between the grab samples and a given indoor integrated sample was nearly as good as between integrated samples taken at different living area locations.  相似文献   

8.
Concentrations of 90Sr, 210Po and 210Pb in lichen and reindeer were studied in central (Østre Namdal) and southern Norway (Vågå) during 2000–2003. The study focussed on potential differences in concentrations of these nuclides in reindeer of different ages. Concentrations of 90Sr in bones of ∼10 year old adult females were about 40% higher than those in calves' antlers (90Sr concentrations in antlers and bones of calves are similar), while the available data from Vågå suggest that 90Sr concentrations in reindeer calves decreased with an effective ecological half-time of 9.03 ± 0.06 years during 1988–2002. Furthermore, 90Sr concentrations were 50–80% higher in bone of reindeer of a similar age from Vågå compared to those from Østre Namdal. Concentrations of 210Po and 210Pb in muscle and liver tissues were comparable to those reported for reindeer in other Nordic areas, with no significant difference in 210Po and 210Pb concentrations between adults and calves or between reindeer from the two different study areas.  相似文献   

9.
4-Nonylphenol (NP) and bisphenol A (BPA) are phenolic substances used in high volumes by the industry. Studies on cells and in experimental animals have shown that both these compounds can be classified as estrogenic hormone disrupters. Information about the exposure of humans to NP and BPA is still scarce, especially regarding levels in human blood. The first aim of this study was to investigate possible sources of NP and BPA exposure from food, by analyzing the levels of NP and BPA from a Swedish food market basket, based on the Swedish per capita food consumption. A second aim was to investigate blood serum levels of NP and BPA, as well as NP-ethoxylates, among young women in Sweden (n = 100). Moreover, associations between food consumption and blood NP and BPA levels were studied. In food, NP was to some extent found at levels above limit of quantification (LOQ 20 ng/g fresh weight) in fruits, cereal products, vegetables, and potatoes. BPA levels above LOQ (2 ng/g fresh weight) were found in fish, meats, potatoes, and dairy products. The estimated mean intakes per capita were (medium bound) 27 μg NP/day and 3.9 μg BPA/day, showing that food is a source of BPA and NP in the general Swedish population. In blood serum, free NP above limit of detection (LOD 0.5 ng/g) was detected in 46% of the study participants while detectable levels of total NP (LOD 0.8 ng/g) were observed in 43%. The corresponding percentages for BPA were 25% and 22%, respectively. The results indicate that there is a continuous source of exposure to NP and BPA that is high enough for free NP and BPA to be detected in some consumers. Among the participants with quantifiable levels of free and total NP (n = 38), 85% (median, range: 38–112%) of the NP was present as free NP. For BPA 76% (49–109%) was detected as free BPA (n = 15). All women had levels of ethoxylates of NP below LOD (0.1–0.7 ng/g). A significantly higher total consumption of fruits and vegetables was reported in questionnaires by participants with NP levels at or above LOD than among women with levels below LOD. This result is supporting the market basket results of relatively high NP levels in these types of food.  相似文献   

10.
BackgroundAlthough antibiotic use during early life has been demonstrated to be related to the altered adipogenesis in later life, limited data are available for the effect of antibiotic exposure in school children on adiposity from various sources, including from the use or contaminated food or drinking water.ObjectiveTo explore the association between the internal exposure of antibiotics from various sources and adipogenesis in school children using the biomonitoring of urinary antibiotics.MethodsAfter 586 school children aged 8–11 years were selected from Shanghai in 2013, total urinary concentrations (free and conjugated) of 21 common antibiotics from six categories (macrolides, β-lactams, tetracyclines, fluoroquinolones, sulfonamides, and phenicols), including five human antibiotics (HAs), two antibiotics preferred as HA, four veterinary antibiotics (VAs), and ten antibiotics preferred as VA, were measured by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Creatinine-corrected urinary concentrations of antibiotics were used to assess their exposure. Overweight or obesity was determined by the body mass index or waist circumference-based criteria deriving from national data.ResultsAll 21 antibiotics were found in urines with the overall detection frequency of 79.6%. The multinomial logistic regression analyses showed the significant associations of overweight and obesity with the exposure to VAs and antibiotics preferred as VA, but not with HAs or antibiotics preferred as HA. After adjusted for a number of obesity-relevant variables, the odds ratios (95% confidence interval) of BMI-based obesity risk of tertiles 2 and 3 of urinary concentrations relative to tertile 1 were respectively 2.54 (1.27, 5.07) and 2.92 (1.45, 5.87) for florfenicol, 0.57 (0.12, 2.63) and 3.63 (1.41, 9.32) for trimethoprim, and 3.00 (1.56, 5.76) and 1.99 (0.99, 4.01) for sum of veterinary antibiotics. Similar results were found when the outcome used WC-based obesity risk. The associations were sex related and mainly observed in boys.ConclusionsSome types of antibiotic exposure, which were mainly from food or drinking water, were associated with an increased risk of obesity in school children. Due to the cross-sectional design, more longitudinal and experimental studies are warranted to further test these findings.  相似文献   

11.
中国进出口贸易中的隐含能估算   总被引:11,自引:0,他引:11  
采用投入产出法。估算了1997-2006年中国进出口贸易中的隐含能。在考虑隐含能和进出口能源产品的情况下,都按我国的能耗效率对进出口进行的保守估计发现:1997-2006年,我国的能源进出口基本持平.其中1999-2005年是一个微弱的能源净进口国,而1997。1998和2006年却是能源净出口国;按照日本的能耗效率对进口产品进行调整后的乐观估计发现中国则是一个更大的能源净出口国,每年能源净出口量在10000-50000万t标煤之间,其中1997-2002年我国能源净出口量占当年能源消费总量的10%左右。之后该数字迅速增长,2006年更高达18.8%。可见我国进口的能源(包括进口产品中的隐含能)又以出口产品的形式输出到了国外。从能源净消费的角度看我国并没有多消费世界上其他国家的能源。虽然我国近年来能源产品进口增加较快,但我国快速增长的净出口使这些能源又“隐含”在产品中离开了中国。  相似文献   

12.
中国进出口贸易中的隐含碳估算   总被引:34,自引:0,他引:34  
采用投入产出法。估算了1997-2006年中国进出口贸易中的隐含碳。对进出口商品都采用中国的碳耗水平所作的保守估计发现:1997-2006年,通过产品的形式,我国为国外排放了大量的碳,1997-2004年。隐含碳净出口占当年碳排放总量的比倒在0.5%-2.7%之间,2004年之后迅速增加。2006年该数字达10%左右。按照日本的碳耗效率对进口产品进行调整后的乐观估计发现。中国为j国该外转移排放的碳数量更为惊人。1997-2002年隐含碳净出口量占当年碳排放总量的12%~14%。2002年之后迅速增加,到2006年,该数字已达29.28%。作为生产者和消费者,中国和其出口国都是这些碳排放的受益者,都应该对气候变化负责。一味对中国增长的碳排放进行指责是不全面的。  相似文献   

13.
Fate and transport of pathogens in lakes and reservoirs   总被引:3,自引:0,他引:3  
Outbreaks of water-borne disease via public water supplies continue to be reported in developed countries even though there is increased awareness of, and treatment for, pathogen contamination. Pathogen episodes in lakes and reservoirs are often associated with rain events, and the riverine inflow is considered to be major source of pathogens. Consequently, the behaviour of these inflows is of particular importance in determining pathogen transport and distribution. Inflows are controlled by their density relative to that of the lake, such that warm inflows will flow over the surface of the lake as a buoyant surface flow and cold, dense inflows will sink beneath the lake water where they will flow along the bathymetry towards the deepest point. The fate of pathogens is determined by loss processes including settling and inactivation by temperature, UV and grazing. The general trend is for the insertion timescale to be shortest, followed by sedimentation losses and temperature inactivity. The fate of Cryptosporidium due to UV light inactivation can occur at opposite ends of the scale, depending on the location of the oocysts in the water column and the extinction coefficient for UV light. For this reason, the extinction coefficient for UV light appears to be a vitally important parameter for determining the risk of Cryptosporidium contamination. For risk assessment of pathogens in supply reservoirs, it is important to understand the role of hydrodynamics in determining the timescale of transport to the off-take relative to the timescale of inactivation. The characteristics of the riverine intrusion must also be considered when designing a sampling program for pathogens. A risk management framework is presented that accounts for pathogen fate and transport for reservoirs.  相似文献   

14.
Soil samples collected from locations in Kosovo where depleted uranium (DU) ammunition was expended during the 1999 Balkan conflict were analysed for uranium and plutonium isotopes content (234U, 235U, 236U, 238U, 238Pu, (239 + 240)Pu). The analyses were conducted using gamma spectrometry (235U, 238U), alpha spectrometry (238Pu, (239 + 240)Pu), inductively coupled plasma-mass spectrometry (ICP-MS) (234U, 235U, 236U, 238U) and accelerator mass spectrometry (AMS) (236U)). The results indicated that whenever the U concentration exceeded the normal environmental values (approximately 2 to 3 mg/kg) the increase was due to DU contamination. 236U was also present in the released DU at a constant ratio of 236U (mg/kg)/238U (mg/kg) = 2.6 x 10(-5), indicating that the DU used in the ammunition was from a batch that had been irradiated and then reprocessed. The plutonium concentration in the soil (undisturbed) was about 1 Bq/kg and, on the basis of the measured 238Pu/(239 + 240)Pu, could be entirely attributed to the fallout of the nuclear weapon tests of the 1960s (no appreciable contribution from DU).  相似文献   

15.
To date, personal volatile organic compounds (VOCs) exposure and residential indoor and outdoor VOCs levels have not been characterized in Korea. In this study, residential indoor and outdoor VOCs concentrations were measured and compared simultaneously with the personal exposure for each of 30 participants in a medium city, Asan, and in a metropolitan city, Seoul. Factors that influence personal VOCs exposures were assessed in relation to house characteristics and time activity information. All VOC concentrations were measured using passive samplers during a 24-h period and analyzed using GC-MS. Ten target VOCs were benzene, trichloroethylene, toluene, o-xylene, p-xylene, ethylbenzene, MIBK, n-octane, styrene, and 1,2-dichlorobenzene. Residential indoor and outdoor VOCs concentrations measured in Seoul were significantly higher than those in Asan. Indoor/outdoor (I/O) ratios for all target compounds ranged from 0.94 to 1.51 and I/O ratios of Asan were a little higher than those of Seoul. Results indicate that time activity information can be used to predict personal exposures, although such predictions will result in an over estimation compared to measured exposures. Factors which influence the indoor VOCs level and its personal exposure in relation to house characteristics included house age, indoor smoking, and house type.  相似文献   

16.
Eight organic UV filters and stabilizers were quantitatively determined in wastewater sludge and effluent, landfill leachate, sediments, and marine and freshwater biota. Crab, prawn and cod from Oslofjord, and perch, whitefish and burbot from Lake Mjøsa were selected in order to evaluate the potential for trophic accumulation. All of the cod livers analysed were contaminated with at least 1 UV filter, and a maximum concentration of almost 12 μg/g wet weight for octocrylene (OC) was measured in one individual. 80% of the cod livers contained OC, and approximately 50% of cod liver and prawn samples contained benzophenone (BP3). Lower concentrations and detection frequencies were observed in freshwater species and the data of most interest is the 4 individual whitefish that contained both BP3 and ethylhexylmethoxycinnamate (EHMC) with maximum concentrations of almost 200 ng/g wet weight. The data shows a difference in the loads of UV filters entering receiving water dependent on the extent of wastewater treatment. Primary screening alone is insufficient for the removal of selected UV filters (BP3, Padimate, EHMC, OC, UV-234, UV-327, UV-328, UV-329). Likely due in part to the hydrophobic nature of the majority of the UV filters studied, particulate loading and organic carbon content appear to be related to concentrations of UV filters in landfill leachate and an order of magnitude difference in these parameters correlates with an order of magnitude difference in the effluent concentrations of selected UV filters (Fig. 2). From the data, it is possible that under certain low flow conditions selected organic UV filters may pose a risk to surface waters but under the present conditions the risk is low, but some UV filters will potentially accumulate through the trophic food chain.  相似文献   

17.
Both climate extremes and agricultural disasters have been reported to increase in recent decades; however, so far, we have little idea on the characteristics of agricultural disasters changes, as well as their meteorological and agronomic causes. Here, using the observed records on rice disasters at agro-meteorological stations across China and the meteorological indexes, we investigated the temporal and spatial changes of major rice disasters occurrence frequency and their relationships to climate change, climate extremes and agronomic practices from 1991 to 2009. We presented the temporal and spatial changes in occurrence frequency of major rice disasters, including droughts, floods, heat stress, chilling damage, insects and diseases, during the warmer period of 2000–2009, in comparison with the period of 1991–2000, based on both the observed records and the meteorological indexes. The results showed that changes in rice disasters could be largely ascribed to changes in climate extremes in recent decades. Floods, insects and diseases occurred more frequently at earlier growth stages; in contrast, chilling damage occurred more frequently at later growth stages in southwestern China during the period of 2000–2009, in comparison with the period of 1991–2000. Our findings highlighted the options should be taken timely and scientifically to reduce the disasters and to cope with ongoing climate change, based on the characteristics of agricultural disasters changes in recent decades.  相似文献   

18.
The occurrence, partitioning and risk of eight polybrominated diphenyl ethers (PBDEs), nine new brominated (NBFRs) and ten organophosphorus flame retardants (OPFRs) were evaluated in three Spanish rivers suffering different anthropogenic pressures (Nalón, Arga and Besòs). OPFRs were ubiquitous contaminants in water (ΣOPFRs ranging from 0.0076 to 7.2 μg L 1) and sediments (ΣOPFRs ranging 3.8 to 824 μg kg 1). Brominated flame retardants were not detected in waters, whereas ΣPBDEs ranged from 88 to 812 μg kg 1 and decabromodiphenyl ethane (DBDPE) reached 435 μg kg 1 in sediments from the River Besòs, the most impacted river. The occurrence of flame retardants in river water and sediment was clearly associated with human activities, since the highest levels occurred near urban and industrial zones and after wastewater treatment plants discharge. Daphnia magna toxicity was carried out for OPFRs, the most ubiquitous flame retardants, considering individual compounds and mixtures. Toxicity of nine tested OPFRs differed largely among compounds, with EC50 values ranging over three magnitude orders (0.31–381 mg L 1). Results evidenced that these compounds act by non-polar narcosis, since their toxicity was proportional to their lipophilicity (Kow). Furthermore, their joint toxicity was additive, which means that single and joint toxicity can be predicted knowing their concentration levels in water using quantitative structure activity relationships (QSARs) and predictive mixture models. Based on these results, a risk assessment considering joint effect was performed calculating and summing risk quotients (RQs) for the water and sediment samples. No significant risk to D. magna (ΣRQs < 1) was observed for any of the monitored rivers.  相似文献   

19.
Indoor air pollution is closely related to children's health. Polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) transmitted through indoor PM2.5 and dust, along with carbonyl compounds and black carbon (BC) aerosol were analysed in five Hong Kong kindergartens. The results showed that 60% of the median PM2.5 levels (1.3 × 101 to 2.9 × 101 μg/m3 for indoor; 9.5 to 8.8 × 101 μg/m3 for outdoor) in the five kindergartens were higher than the guidelines set by the World Health Organization (2.5 × 101 μg/m3). Indoor PM2.5 mass concentrations were correlated with outdoor PM2.5 in four of the kindergartens. The PBDEs (0.10–0.64 ng/m3 in PM2.5; 0.30–2.0 × 102 ng/g in dust) and DP (0.05–0.10 ng/m3 in PM2.5; 1.3–8.7 ng/g in dust) were detected in 100% of the PM2.5 and dust samples. Fire retardant levels in the air were not correlated with the levels of dust in this study. The median BC concentrations varied by > 7-fold from 8.8 × 102 ng/m 3 to 6.7 × 103 ng/m 3 and cooking events might have caused BC concentrations to rise both indoors and outdoors. The total concentrations of 16 carbonyls ranged from 4.7 × 101 μg/m3 to 9.3 × 101 μg/m3 indoors and from 1.9 × 101 μg/m3 to 4.3 × 101 μg/m3 outdoors, whilst formaldehyde was the most abundant air carbonyl. Indoor carbonyl concentrations were correlated with outdoor carbonyls in three kindergartens. The health risk assessment showed that hazard indexes (HIs) HIs of non-cancer risks from PBDEs and DPs were all lower than 0.08, whilst non-cancer HIs of carbonyl compounds ranged from 0.77 to 1.85 indoors and from 0.50 to 0.97 outdoors. The human intake of PBDEs and DP through inhalation of PM2.5 accounted for 78% to 92% of the total intake. The cancer hazard quotients (HQs) of formaldehyde ranged from 4.5E  05 to 2.1E  04 indoors and from 1.9E  05 to 6.2E  05 outdoors. In general, the indoor air pollution in the five Hong Kong kindergartens might present adverse effects to children, although different schools showed distinct pollution levels, so indoor air quality might be improved through artificial measures. The data will be useful to developing a feasible management protocol for indoor environments.  相似文献   

20.
Scales and sludge generated during oil extraction and production can contain uranium, thorium, radium and other natural radionuclides, which can cause exposure of maintenance personnel. This work shows how the oil content can influence the results of measurements of radionuclide concentration in scale and sludge. Samples were taken from a PETROBRAS unit in Northeast Brazil. They were collected directly from the inner surface of water pipes or from barrels stored in the waste storage area of the E&P unit. The oil was separated from the solids with a Soxhlet extractor by using aguarras at 90+/-5 degrees C as solvent. Concentrations of 226Ra and 228Ra in the samples were determined before and after oil extraction by using an HPGe gamma spectrometric system. The results showed an increase in the radionuclide concentration in the solid (dry) phase, indicating that the above radionuclides concentrate mostly in the solid material.  相似文献   

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