Pharmaceuticals reach terrestrial environments through the application of treated wastewaters and biosolids to agricultural soils. We have investigated the toxicity of 15 common pharmaceuticals, classified as nonsteroidal anti-inflammatory drugs (NSAIDs), blood lipid-lowering agents, β-blockers and antibiotics, in two photosynthetic organisms. Twelve pharmaceuticals caused inhibitory effects on the radicle and hypocotyl elongation of Lactuca sativa seeds. The EC50 values obtained were in the range of 170–5656 mg L−1 in the case of the radicle and 188–4558 mg L−1 for the hypocotyl. Propranolol was the most toxic drug for both root and hypocotyl elongation, followed by the NSAIDs, then gemfibrozil and tetracycline. Other effects, such as root necrosis, inhibition of root growth and curly hairs, were detected. However, even at the highest concentrations tested (3000 mg L−1), seed germination was not affected. NSAIDs decreased the photosynthetic yield of Chlamydomonas reinhardtii, but only salicylic acid showed EC50 values below 1000 mg L−1. The first effects detected at low concentrations, together with the concentrations found in environmental samples, indicate that the use of biosolids and wastewaters containing pharmaceuticals should be regulated and their compositions assessed in order to prevent medium- and long-term impacts on agricultural soils and crops.
Strategic planning to increase forest cover in Central American transboundary areas of the Mesoamerican Biological Corridor requires understanding land-cover and land-use change trends and drivers. We estimated forest cover change from remotely sensed land-cover and land-use classifications from 1986, 2001, and 2010, in the tri-national Trifinio Region, bordering El Salvador, Guatemala, and Honduras. Our analysis spanned subnational, national, regional, and protected border areas. We determined correlations with direct drivers of deforestation, developing a multilevel linear regression model. Higher population density significantly correlated with deforestation; coffee, agroforestry, and pasture replaced forests. The tri-national park retained forests compared to neighboring areas, but additionality requires more research. The literature on drivers suggests similar processes and factors in other tropical regions. Forest cover governance efficacy is highly variable. Results indicate relationship between governance and forest cover though more comprehensive understanding of this complex region is needed to determine their causality. 相似文献
A particular agricultural waste, peanut shell, has been used as precursor for activated carbon production by chemical activation with H3PO4. Unoxidized activated carbon was prepared in nitrogen atmosphere which was then heated in air at a desired temperature to get oxidized activated carbon. The prepared carbons were characterized for surface area, surface morphology, and pore volume and utilized for the removal of Cr(VI) from aqueous solution. Batch mode experiments were conducted to study the effects of pH, contact time, particle size, adsorbent dose, initial concentration of adsorbate, and temperature on the adsorption of Cr(VI). Cr(VI) adsorption was significantly dependent on solution pH, and the optimum adsorption was observed at pH 2. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to analyze the kinetic data obtained at different initial Cr(VI) concentrations. The adsorption kinetic data were described very well by the pseudo-second-order model. Equilibrium isotherm data were analyzed by the Langmuir, Freundlich, and Temkin models. The results showed that the Langmuir adsorption isotherm model fitted the data better in the temperature range studied. The adsorption capacity which was found to increase with temperature showed the endothermic nature of Cr(VI) adsorption. The thermodynamic parameters, such as Gibb’s Free energy change (ΔG°), standard enthalpy change (ΔH°), and standard entropy change (ΔS°) were evaluated. 相似文献
The occurrence of the emerging chlorinated flame retardant Dechlorane Plus (DP) and three of its possible degradation products was investigated in white stork eggs from two colonies in Spain. The average DP concentrations were 401 pg/g wet weight (w.w.) for the urban/industrial colony and 105 pg/g w.w. for the rural colony. One possible degradation product, anti-[DP-1Cl], was found in approximately 10% of the samples. No significant stereoisomer enrichments were detected in any colony based on the average anti-DP fractional abundances found which agrees with previous studies in herring gulls. The relationship between DP and PBDE contents in both colonies was explored leading to different scenarios, i.e. no correlation was found in the urban colony but they were statistically correlated in the rural colony. To the best of our knowledge, this is the first study to report DP in a species from a terrestrial food web, and also to report a DP degradation product in biota. 相似文献
Polybrominated diphenyl ethers (PBDEs) are ubiquitous pollutants for which there is still a lack of knowledge about the environmental behavior and fate of the higher brominated congeners (octa- to deca-BDEs). In this study, the PBDE content and congener profiles in failed eggs from two colonies of white stork (Ciconia ciconia) in Spain were studied. The average total PBDE concentration was 1.64ng/g (wet weight, w.w.) for the rural colony and 9.08ng/g (w.w.) for the urban colony. Higher brominated BDEs dominated the congener profiles of both colonies. Of particular interest was the determination of BDE-209 as the dominant congener accounting for 44.1% and 38.6% of the total PBDE content in the rural and urban colonies, respectively. BDE-202, considered an indicator of BDE 209 debromination, was detected in 83% and all of the samples from rural and urban colonies, respectively. The observed congener profile in which BDE-207>BDE-208>BDE-206 does not correspond to any known technical PBDE mixture and is evidence for possible BDE-209 degradation. 相似文献
In recent years, the goal of nature preservation has faced, almost worldwide, an increase in the number of visitors who are interested in experiencing protected areas resources, landscapes and stories. Spain is a good example of this process. The rapidly increasing numbers of visitors have prompted administrations and managers to offer and develop a broad network of facilities and programs in order to provide these visitors with information, knowledge and recreation. But, are we doing it the best way? This research focuses on developing and applying a new instrument for evaluating the quality of visitor management in parks. Different areas are analyzed with this instrument (78 semi-quantitative indicators): planning and management capacity (planning, funding, human resources), monitoring, reception, information, interpretation, environmental education, training, participation and volunteer's programs. Thus, we attempt to gain a general impression of the development of the existing management model, detecting strengths and weaknesses. Although Spain's National Parks constituted the specific context within which to develop the evaluation instrument, the design thereof is intended to provide a valid, robust and flexible method for application to any system, network or set of protected areas in other countries. This paper presents the instrument developed, some results obtained following its application to Spanish National parks, along with a discussion on the limits and validity thereof. 相似文献