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1.
The number of areas affected by toxic harmful algal bloom (HAB) in the Philippines has been increasing since its first recorded occurrence in 1983. Thus far, HAB has been reported in about 20 areas in the Philippines including major fishery production areas. The HAB-causing organism (Pyrodinium bahamense var. compressum) produces a cyst during its life cycle. Pyrodinium cysts which are deposited in the sediment column may play a role in initiating a toxic bloom. 210Pb-derived sedimentation rate studies in the two important fishing grounds of Manila Bay and Malampaya Sound, Palawan have shown that Pyrodinium cysts may have been present in the sediment even before the first recorded toxic algal bloom in these areas. High sedimentation rates (approximately 1 cm/year) have been observed in the northern and western parts of Manila Bay. The results indicate that the sedimentation processes occurring in these bays would require subsurface cyst concentration analysis in evaluating the potential of an area to act as seed bed.  相似文献   

2.
Pentachlorophenol (PCP) was investigated in freshwater sediments and human breast milk collected from the Pearl River Delta, China. The average level of PCP in river sediments was 7.93 ng/g based on dry weight, ranging from 1.44 to 34.4 ng/g. As to the sediments from fishponds, samples from Zhongshan had the highest PCP levels (37.5 ng/g on average), followed by Dongguan (21.1 ng/g on average) and the least in Shenzhen (3.69 ng/g on average) and Shunde (2.20 ng/g on average). Negative relationship was obtained between the PCP level and pH value in sediment (r=0.553, n=13, p<0.05), while positive relationship was found between the PCP levels and the total organic matter (TOM) levels in sediment (r=0.700, n=17, p<0.01). These results indicated that pH and TOM played important roles during the process of PCP settling down to the sediment. PCP was also detected in human breast milk with an average of 2.15 ng/g. The PCP concentration increased with the age increasing of donors. The estimated PCP body burden for mother, daily and yearly PCP intake of infants ranged from 0.16 to 4.17 mg/person, from 0.26 to 10.23 mug/infant.day and from 0.09 to 3.73 mg/infant.year, respectively.  相似文献   

3.
Environment, Development and Sustainability - Cyanobacteria are a group of diverse prokaryotes that are capable of oxygenic photosynthesis. They are ubiquitous in nature and have been reported to...  相似文献   

4.
The aim of this research was to evaluate the possible contamination by heavy metals of milk from cows bred on various farms in Calabria. The concentrations of heavy metals were determined in 40 samples of bovine milk from the various dairy farms. Each sample, homogenized and powdered, was mineralized in a microwave oven. Quantitative analyses of Cd, Cr, Cu, Pb and Se were performed using an atomic absorption spectrophotometer with graphite furnace; As was analyzed by hot vapor generation technique and Zn with the flame method. As regards toxic heavy metals, highest values are those of As (g.m. 37.90 microg/kg w.w.) and Pb (g.m. 1.32 microg/kg w.w.), while lowest concentrations are those of Cd (g.m. 0.02 microg/kg w.w). With regard to essential metals, Zn (g.m. 2016 microg/kg w.w) and Se (g.m. 13.24 microg/kg w.w.) showed the highest concentrations, followed by Cr (g.m. 2.03 microg/kg w.w.) and Cu (g.m. 1.98 microg/kg w.w.). Further investigations of the levels of heavy metals (As) in a greater number of milk samples from various zones of Calabria are necessary, both to examine this problem from the clinical epidemiological point of view and to identify the possible causes of milk contamination.  相似文献   

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Carnivore attacks on livestock are a primary driver of human–carnivore conflict and carnivore decline globally. Livestock depredation is particularly threatening to carnivore conservation in Central India, a priority landscape and stronghold for the endangered tiger. To strengthen the effectiveness of conflict mitigation strategies, we examined the spatial and temporal patterns and physical characteristics of livestock depredation in Kanha Tiger Reserve. We combined livestock compensation historical records (2001–2009) with ground surveys (2011–2012) and carnivore scat to identify when and where livestock species were most vulnerable. Between 400 and 600 livestock were reported for financial compensation each year, and most (91–95 %) were successfully reimbursed. Tigers and leopards were responsible for nearly all livestock losses and most often killed in the afternoon and early evening. Cattle and buffalo were most at risk in dense forests away from villages and roads, whereas goats were most often killed in open vegetation near villages. A spatial predation risk model for cattle revealed high-risk hotspots around the core zone boundary, confirming the significant risks to livestock grazing illegally in the core. Such ecological insights on carnivore–livestock interactions may help improve species-specific livestock husbandry for minimizing livestock losses and enabling coexistence between people and carnivores.  相似文献   

6.
We investigated the vertical profiles of 239+240Pu, 137Cs, and excess 210Pb (210Pbex) in sediment core samples obtained from two freshwater lakes and two brackish lakes situated near the first commercial spent nuclear fuel reprocessing plant in Rokkasho, Japan, before the final test of the plant using actual spent nuclear fuel. The inventory of 239+240Pu in those lakes was larger than that in soil in Rokkasho, which indicated the inflow of 239+240Pu from the catchment area in addition to direct deposition on the lake surfaces. The 137Cs inventory in sediments of the brackish lakes was lower than that in the soil, which showed that part of the 137Cs was removed from the sediments by the brackish water or that it was not deposited into the sediments, because of the high solubility of Cs in brackish water. The 137Cs inventory in sediments of the freshwater lakes was higher than that of the brackish lakes, and comparable with that in soil except for one core sample out of four. The 239+240Pu/137Cs ratio in freshwater lake sediments was higher than that in soil, and that indicated that part of the 137Cs was lost from the sediments. The low inventory of 137Cs may be attributable to competition for absorption sites in sediments with ammonium ions formed in the reducing environment which occurs from summer to fall in the sediments. Those data will be used as background data on the artificial radionuclides in the lakes to assess the effect of released radionuclides on their concentrations.  相似文献   

7.
This work analyzes the seasonal variation (winter and summer) of ten drugs of abuse, six metabolites and three benzodiazepines in surface waters from the Jarama and Manzanares Rivers in the Madrid Region, the most densely populated area in Spain. The occurrence of these compounds in tap water in this region is also investigated and a preliminary human health risk characterization performed for those substances found in tap water. Finally, a screening level risk assessment that combines the measured environmental concentrations (MECs) with dose–response data to estimate Hazard Quotients (HQs) for the compounds studied is also presented.The results of this study show the presence of fourteen out of the nineteen compounds analyzed in winter and twelve of them in summer. The most ubiquitous compounds, with a frequency of detection of 100% in both seasons, were the cocaine metabolite benzoylecgonine (BE), the amphetamine-type stimulant (ATS) ephedrine (EPH), the opioid methadone (METH), the METH metabolite 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and the three benzodiazepines investigated, namely alprazolam (ALP), diazepam (DIA) and lorazepam (LOR). The highest concentrations observed corresponded to EPH (1020 ng L 1 in winter and 250 ng L 1 in summer). The only compounds not detected in both seasons were heroin (HER) and its metabolite 6-acetylmorphine (6ACM), lysergic acid diethylamide (LSD) and its metabolite 2-oxo-3-hydroxy-LSD (O-H-LSD), and Δ9-tetrahydrocannabinol (THC). In terms of overall concentration, all sampling points presented higher concentrations in winter than in summer. Statistical analyses performed to gather evidence concerning occasional seasonal differences in the concentrations of individual substances between summer and winter showed statistically significantly higher concentrations (p < 0.05) of BE, EPH and the opioid morphine (MOR) in winter than in summer. Two out of the nineteen compounds studied, namely cocaine (CO) and EPH, were detected in tap water from one sampling point at concentrations of 1.61 and 0.29 ng L 1, respectively. The preliminary human health risk characterization showed that no toxic effects could be expected at the detected concentration level in tap water.The screening level risk assessment showed that MOR, EDDP and the THC metabolite 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) were present in at least one of the sampling sites in a concentration leading to a Hazard Quotient (HQ) value between 1.0 and 10.0, thus indicating some possible adverse effects. The cumulative HQ or Toxic units (TUs) calculated for each of the groups studied showed that opioids and cannabinoids were present at concentrations high enough to potentially generate some adverse effects on at least one sampling point.  相似文献   

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As the societal benefits associated with transitioning to more sustainable, less fossil fuel-reliant energy systems are increasingly recognized by communities throughout the world, the potential of creating ‘green jobs’ within a ‘green economy’ is attracting much attention. Green energy clusters are increasingly promoted throughout the world as a strategy to simultaneously promote economic vitality and stimulate a sustainable energy transition. In spite of their emerging role in regional-scale sustainability planning efforts, such initiatives have not been considered within the sustainability transitions literature. This paper explores the development of one such regional sustainable energy cluster initiative in Central Massachusetts in Northeastern USA to consider the potential for such cluster initiatives to contribute to socio-technical transition in the energy system. Since 2008, a diverse set of stakeholders in Central Massachusetts, including politicians, universities, businesses, local citizens, and activists, have been working toward facilitating the emergence of an integrated cluster of activity focused on sustainable energy. Through interviews with key actors, participant observation, and document review, this research assesses the potential of this cluster initiative to contribute to a regional socio-technical transition. The empirical details of this case demonstrate that sustainable energy cluster initiatives can potentially accelerate change in entrenched energy regimes by promoting institutional thickness, generating regional ‘buzz’ around sustainable energy activities, and building trust between multiple and diverse stakeholders in the region. This research also contributes to emerging efforts to better ground socio-technical transitions in geographic space.  相似文献   

10.
Both the World Health Organization and the UK Expert Panel on Air Quality Standards (EPAQS) have considered benzo(a)pyrene (BaP) as a marker of the carcinogenic potency of the polycyclic aromatic hydrocarbons (PAH) mixture, when recommending their respective guidelines for PAHs in outdoor air. The aim of this research is to compare the concentrations and relative abundance of individual PAH and their contribution to the overall carcinogenic potential of the PAH mixture in indoor and outdoor environments to assess the suitability of the UK air quality standard derived for outdoor air for use as a guideline for indoor environments. Samples were collected onto filters using active sampling in different indoor and outdoor microenvironments. The ratio of individual compounds to BaP, the BaP equivalent concentrations and the percentage contribution of each individual compound to the total carcinogenic potential of the PAH mixture were calculated. Mean concentrations were generally lower indoors (BaP=0.10 ng/m(3)) than outdoors (BaP=0.19 ng/m(3)), with the exception of indoor environments with wood burners (BaP=2.4 ng/m(3)) or ETS (BaP=0.6 ng/m(3)). The ratio of individual PAHs to BaP showed no significant differences between indoors (e.g. DahA/BaP=0.27) and outdoors (DahA/BaP=0.31). The relative contribution of BaP to the PAH overall carcinogenic potency is similar indoors (49%), outdoors (54%) and in the smelter environment (48%) used by EPAQS to derive the UK Air Quality Standard for ambient air. These results suggest the suitability of BaP as a marker for the carcinogenic potential of the PAH mixture irrespective of the environment. Despite small differences in PAH mixture composition indoors and outdoors, the level of protection afforded by the present EPAQS standard is likely to be similar whether it is applied to indoor or outdoor air.  相似文献   

11.
Polybrominated diphenyl ethers (PBDEs) and the organochlorine compounds polychlorinated biphenyls (PCBs), DDTs, HCB, chlordane-related pesticides, HCH and toxaphene were analysed in blubber of juvenile ringed seals from Central West Greenland collected between 1982 and 2006. The longest time series could be established for PBDEs, partly based on archived material, while PCBs and DDTs covered a study period from 1994-2006. All organochlorines showed decreasing trends, most pronounced for DDT and HCH with an annual change of 8%. BDE-47 had a significantly increasing trend of 5% annually. It was the only BDE congener consistently above the detection limit, with annual median concentrations between 0.78 ng/g lw to 3.54 ng/g lw, i.e. about 10 times lower than values from East Greenland observed in a similar time trend study on ringed seal blubber [Rigét F, Vorkamp K, Dietz R, Rastogi SC. Temporal trend studies on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ringed seals from East Greenland. J Environ Monit 2006; 8: 1000-5]. A clear East>West difference was also found for PCBs and DDTs, but not for chlordanes, toxaphene or HCHs. Sigma 10-PCB, Sigma DDT and Sigma Chlordanes had similar annual median concentrations, typically exceeding SigmaPBDE by two orders of magnitude. The concentrations of HCH and toxaphene were in an intermediate group, with highest annual median concentrations of 135 ng/g lw and 20 ng/g lw, respectively. For most compound groups, the circumpolar trend previously established under for example the Arctic Monitoring and Assessment Programme was confirmed, but apparently, more data are needed for chlordane-related compounds and toxaphene. Statistical analyses of the compound patterns in the ringed seal samples revealed significantly greater differences between seals from East and West than between different sampling years. Higher proportions of PCBs and DDTs and lower proportions of chlordanes and HCHs were found in seals from East Greenland than in those from West Greenland. Based on principal component analysis of individual congener and compounds, seals from East Greenland were found to contain higher proportions of the higher chlorinated CB congeners. Varying patterns between sampling locations may be caused by different exposure situations related to contaminant emissions and transport, but different feeding habits may also affect the contaminant composition.  相似文献   

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13.
Average concentrations of polybrominated diphenyl ethers (PBDEs) in dust in 30 homes, 18 offices, and 20 cars were 260,000, 31,000, and 340,000 ng SigmaPBDEs g(-1) respectively. Concentrations of BDEs 47, 99, 100, and 154 in cars exceeded significantly (p<0.05) those in homes and offices. Average concentrations of 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE) and decabromodiphenyl ethane (DBDPE) in homes, offices, and cars respectively were lower at 120, 7.2, and 7.7 ng g(-1) (TBE) and 270, 170, and 400 ng g(-1) (DBDPE). BDE-209 concentrations in three samples are the highest to date at 2,600,000 (car), 2,200,000 (home), and 1,400,000 ng g(-1) (home). UK toddlers daily consuming 200 mg dust contaminated at the 95th percentile concentration, ingest 180 ng (Sigma)tri-hexa-BDEs and 310 microg BDE-209 day(-1). For TBE, exposure was lower than for PBDEs and hexabromocyclododecanes (HBCDs), while that for DBDPE was similar in magnitude to (Sigma)tri-hexa-BDEs, but less than for BDE-209 and HBCDs. BDE-209 concentrations recorded in ten samples taken at monthly intervals in one room varied 400-fold, implying caution when using single measurements of dust contamination for exposure assessment. Significant negative correlation was observed in one room between concentrations of BDE-47, 99, and 153 and dust loading (g dust m(-2) floor), suggesting "dilution" occurs at higher dust loadings.  相似文献   

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Iodine-131 reaches the marine environment through its excretion to the sewer by nuclear medicine patients followed by discharge through coastal and deepwater outfalls. 131I has been detected in macroalgae, which bio-accumulate iodine, growing near the coastal outfall of Cronulla sewage treatment plant (STP) since 1995. During this study, 131I levels in liquid effluent and sludge from three Sydney STPs as well as in macroalgae (Ulva sp. and Ecklonia radiata) growing near their shoreline outfalls were measured. Concentration factors of 176 for Ulva sp. and 526 for E. radiata were derived. Radiation dose rates to marine biota from 131I discharged to coastal waters calculated using the ERICA dose assessment tool were below the ERICA screening level of 10 μGy/hr. Radiation dose rates to humans from immersion in seawater or consumption of Ulva sp. containing 131I were three and two orders of magnitude below the IAEA screening level of 10 μSv/year, respectively.  相似文献   

18.
Today, increasing use intensity and establishment of new sea uses such as offshore wind farming can be observed in coastal and marine waters. This development also increases the pressure on coastal and marine ecosystems. The exclusive economic zone of the German North Sea can serve as an example for this development, in particular illustrating the need to combine multiple uses and societal demands within a given sea area. In order to deal with the resulting conflicts and cumulative impacts, new planning tools and integrated approaches to planning and management are developing. While the sea becomes a contested but at the same time politically recognised area, also conflicts rooted in different perceptions, values and attitudes of coastal people can be observed. In order to deal with the current challenges in marine areas, marine spatial planning and similar tools for integrated planning need to be developed in the form of communication processes, which link diverse sets of information and span a dialogue between groups of society and across spatial scales including the transnational dimension.  相似文献   

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