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791.
Although humans are a major mechanism for short and long distance seed dispersal, there is limited research testing clothing as a vector. The effect of different types of material (sports vs hiking socks), or different items of clothing (boots, socks, laces vs legs) or the same item (socks) worn in different places on seed composition were assessed in Kosciuszko National Park, Australia. Data was analyzed using Repeated Measures ANOVA, independent and paired t-tests, Multi-dimensional Scaling Ordinations and Analysis of Similarity. A total of 24,776 seeds from 70 taxa were collected from the 207 pieces of clothing sampled, with seed identified from 31 native and 19 non-native species. Socks worn off-track collected more native seeds while those worn on roadsides collected more non-native seeds. Sports socks collected a greater diversity of seeds and more native seeds than hiking socks. Boots, uncovered socks and laces collect more seeds than covered socks and laces, resulting in 17% fewer seeds collected when wearing trousers. With seeds from over 179 species (134 recognized weeds) collected on clothing in this, and nine other studies, it is clear that clothing contributes to unintended human mediated seed dispersal, including for many invasive species. 相似文献
792.
Tens of thousands of chemicals are currently marketed worldwide, but only a small number of these compounds has been measured in effluents or the environment to date. The need for screening methodologies to select candidates for environmental monitoring is therefore significant. To meet this need, the Swedish Chemicals Agency developed the Exposure Index (EI), a model for ranking emissions to a number of environmental matrices based on chemical quantity used and use pattern. Here we evaluate the EI. Data on measured concentrations of organic chemicals in sewage treatment plants, one of the recipients considered in the EI model, were compiled from the literature, and the correlation between predicted emission levels and observed concentrations was assessed by linear regression analysis. The adequacy of the parameters employed in the EI was further explored by calibration of the model to measured concentrations. The EI was found to be of limited use for ranking contaminant levels in STPs; the r2 values for the regressions between predicted and observed values ranged from 0.02 (p = 0.243) to 0.14 (p = 0.007) depending on the dataset. The calibrated version of the model produced only slightly better predictions although it was fitted to the experimental data. However, the model is a valuable first step in developing a high throughput screening tool for organic contaminants, and there is potential for improving the EI algorithm. 相似文献
793.
In recent years there has been growing international interest in the assessment of doses and risks from ionising contaminants to biota. In this study the ERICA Tool, developed within the EC 6th Framework Programme, was applied to estimate incremental dose rates to biota in freshwater ecosystems in Finland mainly resulting from exposure to the Chernobyl-derived radionuclides 137Cs, 134Cs and 90Sr. Data sets consisting of measured activity concentrations in fish, aquatic plants, lake water and sediment for three selected lakes located in a region with high 137Cs deposition were applied in the assessment. The dose rates to most species studied were clearly below the screening level of 10 μGy h−1, indicating no significant impact of the Chernobyl fallout on these species. However, the possibility of higher dose rates to certain species living on or in the bottom sediment cannot be excluded based on this assessment. 相似文献
794.
Soudek P Petrová S Benesová D Kotyza J Vágner M Vanková R Vanek T 《Journal of environmental radioactivity》2010,101(6):446-450
A soil-plant transfer study was performed using soil from a former uranium ore processing factory in South Bohemia. We present the results from greenhouse experiments which include estimates of the time required for phytoremediation. The accumulation of 226Ra by different plant species from a mixture of garden soil and contaminated substrate was extremely variable, ranging from 0.03 to 2.20 Bq 226Ra/g DW. We found differences in accumulation of 226Ra between plants from the same genus and between cultivars of the same plant species. The results of 226Ra accumulation showed a linear relation between concentration of 226Ra in plants and concentration of 226Ra in soil mixtures. On the basis of these results we estimated the time required for phytoremediation, but this appears to be too long for practical purposes. 相似文献
795.
V.N. Jha R.M. Tripathi N.K. Sethy S.K. Sahoo A.K. Shukla V.D. Puranik 《Journal of environmental radioactivity》2010,101(9):717-722
A field study has been conducted to evaluate the 226Ra bioaccumulation among aquatic plants growing in the stream/river adjoining the uranium mining and ore-processing complex at Jaduguda, India. Two types of plant group have been investigated namely free floating algal species submerged into water and plants rooted in stream & riverbed. The highest 226Ra activity concentration (9850 Bq kg−1) was found in filamentous algae growing in the residual water of tailings pond. The concentration ratios of 226Ra in filamentous algae (activity concentration of 226Ra in plant Bq kg−1 fresh weight/activity concentration of 226Ra in water Bq l−1) widely varied i.e. from 1.1 × 103 to 8.6 × 104. Other aquatic plants were also showing wide variability in the 226Ra activity concentration. The ln-transformed filamentous algae 226Ra activity concentration was significantly correlated with that of ln-transformed water concentration (r = 0.89, p < 0.001). There was no correlation between the activity concentrations of 226Ra in stream/riverbed rooted plants and the substrate. For this group, correlation between 226Ra activity concentration and Mn, Fe, Cu concentration in plants were statistically significant. 相似文献
796.
S.P. McGrath C. Micó F.J. Zhao 《Environmental pollution (Barking, Essex : 1987)》2010,158(10):3095-3102
The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED50) of Mo in different soils, explaining > 65% of the variance in ED50 for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. 相似文献
797.
通过熏气的方法,比较了在硫氧化物混合污染气体的作用下,木本花卉(月季Rosa chinensis,杜鹃Rhododendron simsii,一品红Euphorbia pulcherrima,茉莉花Jasminum sambac),一、二年生花卉(一串红Salvia splendens,凤仙花Impatiens balsamina),宿根花卉(君子兰Clivia miniata),室内观叶植物(文竹Asparagus setacens,吊兰Chlorophytum comosum,沿阶草Ophiopogon bodinieri,朱蕉Cordyline fruticosa,吊竹梅Zebrina pendula,白斑万年青Dieffenbachia bowmannii)中13种花卉植物的叶片伤害症状及植物抗性表现,并对植物受害后的恢复情况进行了追踪观察。发现在同种污染气体的作用下,不同种类的植物表现出不同的伤害症状。植株不同叶龄的叶片对污染气体的敏感性存在一定的差异,幼龄叶不一定比中老龄叶敏感性强。当污染浓度不超过一定阈值时,花卉植物都有不同程度的恢复能力。利用“花卉植物叶片伤害评价系统”对试验植物叶片伤害症状进行了评价,依据评价结果,对试验植物进行了抗性分级。为保证对植物抗性等级划分的准确性,建议制定统一的熏气浓度标准和评价标准。 相似文献
798.
799.
Kiyoaki Kitamura Kiyoshi Miyajima Tadashi Higashitani Norihide Nakada Koya Komori Yutaka Suzuki 《Journal of the American Water Resources Association》2009,45(1):22-34
Abstract: The objective of this study is to evaluate the effect of estrogens on fish endocrine disruption in river water and treated wastewater. Endogenous estrogen estrone (E1), 17β‐estradiol (E2), river water, and treated wastewater were used for exposure tests on male Japanese medaka. Vitellogenin induction in male medaka was regarded as the endpoint of endocrine disruption. The effective concentrations of E1 and E2 on vitellogenin induction in medaka were evaluated by breeding medaka for 14 days in tanks with various concentrations of E1 or E2. Vitellogenin induction increased with elapse of time during exposure, with higher estrogen concentrations causing greater vitellogenin induction. According to the test results, the lowest observed effect concentrations (LOECs) of E1 and E2 were estimated to be 31.6 and 5.0 ng/l, respectively; and the E2 equivalent (EEQ) LOEC value of E1 was 5.2 ng‐E2/l, derived by multiplying the relative potency of E1 by that of E2 as estimated in this study. In continuous exposure tests using river water or treated wastewater, the estrogenic activity, an index of total estrogenic potential measured by yeast screen assay and expressed as EEQ, varied widely during the exposure tests, and significant vitellogenin induction was observed after several days of high levels of estrogenic activity in water. Vitellogenin concentration tended to significantly increase if EEQ exceeded the level of 5 ng‐E2/l. The threshold value was substantially the same as the results for E1 and E2 exposure tests of medaka. Consequently, EEQ over 5 ng‐E2/l was revealed to have the potential to cause endocrine disruption of male medaka. As estrogenic activity exceeding 5 ng‐E2/l was observed in some rivers in Japan, total estrogenic potential needs to be further decreased at wastewater treatment plants to prevent fish endocrine disruption. 相似文献
800.
An educational project on biological monitoring of air quality was launched in 2004 to involve about 650 young students (age
6 to 16) from 21 schools of nine municipalities in Tuscany (Central Italy) in active detection of the crucial pollutant ozone
with indicator sensitive tobacco seedlings. Results implied the reading of 9,300 raw biological figures and were fortified
by the data captured by six photometric analysers. Under the guidance of their teachers, the students had several opportunities
to practice with many basic and applied study areas and were initiated into the scientific method in a simple and absorbing
manner. Curiosity and involvement were widespread; a sort of emotional and responsible relationship was developed by several
pupils. Though primarily an educational exercise, the survey introduced a research element and the regional picture of air
pollution that emerged has increased our knowledge of the air quality situation in the area. Biological monitoring of air
quality is a powerful tool to improve the awareness and involvement in key topics of environmental education. In addition,
it represents a crucial element for improving the awareness of problems and implies the active participation of citizens in
the assessment of several indicators of the state of the environment. Its potential as a robust implement in landscape and
urban planning is noteworthy. 相似文献