The fate of six human-use drugs was assessed and predicted in mesocosms designed to mimic shallow constructed wetlands during the onset of fall and senescence. Mesocosms were monitored for 28 days after the addition of carbamazepine, clofibric acid, fluoxetine and naproxen (nominal initial concentrations of 5 μg/L each), sulfamethoxazole, and sulfapyridine (nominal initial concentrations of 150 μg/L each), with and without phosphorous (P) addition at 1.6 mg/L. We hypothesized that addition of P would stimulate primary productivity and enhance removal of pharmaceuticals from the water column. Carbamazepine, clofibric acid, fluoxetine, and naproxen had half-lives of 8.7, 11, 1.5, and 2.5, and 8.6, 11.0, 1.4, and 2.5 days in treatments with and without P amendment, respectively. Sulfamethoxazole and sulfapyridine had half-lives of 17 and 4.9 days in mesocosms with P amendment and 17 and 4.7 days without amendment. A concurrent pulse of P with pharmaceuticals did not significantly enhance the removal of these compounds. Predicted half-lives from modeling efforts were consistent with observed values, with photolysis the greatest contributor to chemical attenuation.
Positive static allometry is a scaling relationship where the relative size of traits covaries with adult body size. Traditionally, positive allometry is thought to result from either altered physiological requirements at larger body size or from strongly condition-dependent allocation under sexual selection. Yet, there are no theoretical reasons why positive allometry cannot evolve in fitness-related traits that are solely under the influence of natural selection. We investigated scaling and sexual dimorphism of a naturally selected trait, pectoral fin size, in comparison to a trait important in male–male combat, head width in natural populations of a fish, the desert goby Chlamydogobius eremius. Male desert gobies provide uniparental care and use their pectoral fins to fan the brood (often under hypoxic conditions); hence, larger fins are expected to be more efficient. Male pectoral fins do not appear to fulfil a signalling function in this species. We found that, for both pectoral fin size and head width, males exhibited positive allometric slopes and greater relative trait size (allometric elevation) than females. However, for head width, females also showed positive allometry, albeit to a lesser degree than males. Because fin locomotory function typically does not result in positive allometry, our findings indicate that other naturally selected uses, such as paternal care, can exaggerate trait scaling relationships. 相似文献
The aim of this study was to evaluate the consequence of changing land use from agriculture land to other use purposes with respect to OCPs non-cancer and cancer risk on human health, based on concentrations of DDTs and HCHs in soils collected from 55 locations representing 12 different land use types. There were no non-cancer risks of DDTs and γ-HCHs on adults and children, and there were very low cancer risks of DDD, o,p'-DDE, DDT, α-HCH, β-HCH, γ-HCH based on their total concentrations in all samples. Nonetheless, there were significant correlations of DDT to its metabolites (DDE and DDD) (r = 0.506 and r = 0.648) and DDE to DDD (r = 0.438) both at p < 0.01. OCP levels should be routinely monitored in different environmental media and food in order to verify whether there is fresh input. Their potential risks on human health should also be assessed. 相似文献
Environmental Science and Pollution Research - The processing of rice (Oryza sativa L.) generates large quantities of lignocellulosic wastes termed rice husks (RH). Numerous researchers have... 相似文献
Electronic waste (e-waste) is one of the fastest-growing pollution problems worldwide given the presence if a variety of toxic substances which can contaminate the environment and threaten human health, if disposal protocols are not meticulously managed. This paper presents an overview of toxic substances present in e-waste, their potential environmental and human health impacts together with management strategies currently being used in certain countries. Several tools including Life Cycle Assessment (LCA), Material Flow Analysis (MFA), Multi Criteria Analysis (MCA) and Extended Producer Responsibility (EPR) have been developed to manage e-wastes especially in developed countries. The key to success in terms of e-waste management is to develop eco-design devices, properly collect e-waste, recover and recycle material by safe methods, dispose of e-waste by suitable techniques, forbid the transfer of used electronic devices to developing countries, and raise awareness of the impact of e-waste. No single tool is adequate but together they can complement each other to solve this issue. A national scheme such as EPR is a good policy in solving the growing e-waste problems. 相似文献