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The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000 shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5–13.5 mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1–4.4 mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation.  相似文献   

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Controlled test atmospheres of sidestream and mixed mainstream/sidestream tobacco smoke were produced in a dynamic test chamber of 16.9 m3 volume. University of Kentucky 1R4F research cigarettes were automatically smoked by a Borgwaldt smoking machine. Different target levels of smoke were attained by varying the number of cigarettes being smoked (one or two cigarettes continuously) and dilution airflow through the chamber (1.6 to 7.4 m3/min). For each level, a "smoke index" was calculated as the number of cigarettes being smoked divided by the dilution flow rate. Ultraviolet light-absorbing particulate matter (UVPM); aerosol counts and size distribution; and concentrations of CO, NO2, NH3, formaldehyde, acetaldehyde, acrolein, and nicotine were determined in the test atmospheres and background dilution air. Parameters exhibiting the highest correlations with smoke index (r2 > 0.98) included UVPM, aerosol counts, formaldehyde, and acetaldehyde. The other parameters were also highly correlated with r2 > 0.9 in each case. Differences in concentration for sidestream and mixed mainstream/sidestream atmospheres were statistically significant for acetaldehyde, formaldehyde, and CO; in each case the level was higher in mixed mainstream/sidestream smoke. These results demonstrate the utility of employing multiple markers for assessment of environmental tobacco smoke levels and for dichotomizing the contributions of sidestream and mainstream smoke to these levels. The generation factors developed in this work can be used for estimating required ventilation rates for attainment of target air quality conditions in smoking rooms.  相似文献   

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Automated sediment toxicity testing and biomonitoring has grown rapidly. This study tested the suitability of the marine amphipod Corophium volutator (Pallas, 1766) for sediment biomonitoring using the Multispecies Freshwater Biomonitor (MFB). Two experiments were undertaken to (1) characterize individual behaviors of C. volutator using the MFB and (2) examine behavioral changes in response to sediment spiked with the pesticide Bioban. Four behaviors were visually identified (walking, swimming, grooming and falling) and characterized in the MFB as different patterns of locomotor activity (0-2 Hz range). Ventilation was not visually observed but was detected by the MFB (2-8 Hz). No clear diel activity patterns were detected. The MFB detected an overall increase in C. volutator locomotor activity after Bioban addition to the sediments (56, 100, 121 mg kg(-1)). C. volutator was more active (both locomotion and ventilation) in the water column than the spiked sediment. C. volutator appears a sensitive and appropriate species for behavioral sediment toxicity assessment and biomonitoring.  相似文献   

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Autogenous Aedes (Ochlerotatus) caspius Pallas from Aswan deposits 1 to 2 egg batches without a blood meal. Repeated ovarian developmental cycles were responsible for the bi-ovipositional pattern as indicated by the presence of 2 dilatations in the ovariolar pedicel of bi-autogenous females and by the early stages of development of the ovaries (II and II B) observed 1-3 days following initial oviposition, later stages of maturation occurred progressively. Three levels of autogeny were distinguished within the population: mono-autogenous females that deposited 1 egg batch and were unable to initiate further oogenesis (54.4%), mono-autogenous females in which various degrees of vitellogenesis developed posterior to initial sole oviposition (40%) and bi-autogenous females (5.6%) that deposited 2 autogenous egg batches but were unable to develop any further oogenesis. The fecundity of mono-autogenous females (about 56 eggs) whether they could develop a 2nd autogenous cycle or not, was comparable to that of bi-autogenous mosquitoes in their initial egg batch (53 eggs), suggesting that ability to develop a subsequent autogenous follicular cycle is determined by factors independent of nutrient reserves accumulated during the larval stage. The 2nd egg batch of bi-autogenous females was smaller (21 eggs) than the initial batch. The total reproductive effort of bi-autogenous individuals (about 74 eggs) was superior to that of mono-autogenous females. However, bi-autogenous females laid the totality of their eggs within about 16 days, whereas the average initial gonotrophic cycle of mono-autogenous females was 6 days. It is concluded that bi-autogeny in Ae. caspius would be of little value in the population increase although it may contribute maintaining the species when the host is not available.  相似文献   

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Bulletin of Environmental Contamination and Toxicology - Although water pollution by metals in the Danube River is considered high, little is known about its impact on sturgeons. In this regard,...  相似文献   

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Recently, a novel environmental stress index (ESI) which is composed from commonly used meteorological variables: ambient temperature (T(a)), relative humidity (RH), and solar radiation (SR) was suggested as follows: ESI = 0.63T(a)-0.03RH+0.002SR+0.0054(T(a) x RH)-0.073(0.1+SR)(-1); (degrees C) The purpose of the present study was to evaluate and validate the ESI for hot dry and hot wet climatic conditions. The ESI was applied to large meteorological databases from 2 different locations resembling hot/wet and hot/dry climates. Data analysis revealed high correlation between ESI and the wet bulb globe temperature (WBGT) index for each of the two databases: P < 0.05, R2 = 0.985 and 0.982, for the hot/dry and hot/wet conditions, respectively. Therefore, it is concluded that ESI, which is constructed from fast response and commonly used weather variables (T(a), RH, SR), and also found in a microsensor format is validated for hot/dry and hot/wet zones and as a potential index to serve as an alternative to the WBGT for heat category assessment.  相似文献   

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Neutralizing antibodies to sandfly fever Naples, sandfly fever Sicilian and Toscana viruses were investigated among 479 sera collected from a normal human population in Cyprus. Antibody prevalence rates of 57%, 32% and 20% were found to Naples, Sicilian and Toscana viruses, respectively. The observed frequency of dual and triple infections was higher than would be expected with a random chance of infection. Antibody prevalence rates were similar for men and women for all three viruses tested, but one of two study sites had significantly higher antibody prevalence to Naples and Sicilian viruses than the other. Individuals with antibodies to both Naples and Toscana viruses had higher antibody levels to Naples virus than those with antibodies to Naples virus only. If the antibody prevalence rates found in this study reflect a history of clinical disease as described in the literature, sandfly fever poses a significant public health problem in Cyprus.  相似文献   

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The aim of this study was to investigate the effect of an organophosphorus insecticide omethoate (OM), on certain oxidative stress biomarkers (malondialdehyde (MDA), reduced glutathione (GSH), glutathione-S-transferase (GST), glutathione reductase (GR), catalase (CAT)) in tongue, lung, stomach and muscle tissues of adult frogs (Rana ridibunda Pallas). Animals were exposed to 10 and 20 parts per million dosages of OM for 24, 48, 72 or 96 h. According to the results, MDA level increased significantly in lung and stomach tissues. GSH content fluctuated in lung and muscle while it elevated in tongue and stomach tissues. With regard to antioxidant enzymes (GST, GR and CAT), their activities reduced in tongue, while they increased in lung and fluctuated in stomach and muscle tissues. It can be concluded that exposure of frogs to OM are characterized by increased MDA levels and fluctuated enzyme activities and GSH contents. This may reflect the potential role of these parameters as useful biomarkers for assessment of OM toxicity.  相似文献   

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In patients attributing their health complaints to environmental factors (EnvPat) evidence based medical diagnostics usually do not confirm environmental and somatic causes of symptoms. Many symptoms remain unexplained. Aim of the study was the systematic assessment of medically unexplained physical symptoms (MUPS) in EnvPat and comparison to symptom rates reported by subjects of an environmental study exposed to environmental odors (EnvExp). This specific exposure was chosen, as odors are associated by an unclear mechanism with physical symptoms. By this we aimed to enlighten the open question as to likeliness that MUPS of EnvPat are caused by hitherto unrevealed environmental exposures or result from somatization. MUPS were measured with SOMS-2 in EnvPat n=92, patients presenting in a university environmental outpatients clinic, and different study groups exposed to environmental odors (EnvExp). These were: (1) subjects exposed to annoying odors and medically relevant concentrations of bioaerosols, such as airborne microorganisms (EnvExp-1, n=74), and (2) subjects exposed to odors alone (EnvExp-2, n=282) as well as unexposed controls (Controls, n=235). Logistic regression and analysis of variance were applied to analyze rates of single complaints and the sum index of complaints (SOMS-CoIx). In EnvPat rates of MUPS were highest - significant (p<0.05) adjusted OR in 23 of 25 MUPS compared to controls - and highest SOMS-CoIx (mean 15.3 (S.D. +/-9.3). Rates of MUPS were lower in environmentally exposed subjects with difference in the two strata: while EnvExp-1 differed in several complaints, i.e., nausea and SOMS-CoIx (mean 7.2, S.D. +/-6.9) from controls (p<0.05), EnvExp-2 (SOMS-CoIx mean 4.8, S.D. +/-5.2) showed relevant differences only in two single complaints and not in the SOMS-CoIx from controls, SOMS-CoIx mean 3.9, S.D. +/-5.0. This remained when adjusting for age, gender, and school education. Rates of MUPS in environmental patients were clearly higher than in subjects with actual environmental exposure, making it unlikely that their symptoms are due to undetected environmental factors. MUPS of EnvPat show similarities to psychosomatic patients. In the environmental survey symptom assessment by SOMS-2 was sensitive to different environmental scenarios, i.e., higher rates of physical complaints were only found in subjects with hazardous residential bioaerosols pollution as well as an annoying odor exposure and interestingly not in subjects exposed to annoying odors alone. This underlines that questionnaire data of somatic complaints need to be interpreted on the basis of exposure assessment in order to unjustly attribute health complaints to annoyance.  相似文献   

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