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901.
Industrial activity is one of the main sources of ambient pollution in developed countries. However, research analyzing its effect on birth outcomes is inconclusive. We analyzed the association between proximity of mother’s municipality of residence to industries from 24 different activity groups and risk of very (VPTB) and moderate (MPTB) preterm birth, very (VLBW) and moderate (MLBW) low birth weight, and small for gestational age (SGA) in Spain, 2004–2008. An ecological study was defined, and a “near vs. far” analysis (3.5 km threshold) was carried out using Hierarchical Bayesian models implemented via Integrated Nested Laplace Approximation. VPTB risk was higher for mothers living near pharmaceutical companies. Proximity to galvanization and hazardous waste management industries increased the risk of MPTB. Risk of VLBW was higher for mothers residing near pharmaceutical and non-hazardous or animal waste management industries. For MLBW many associations were found, being notable the proximity to mining, biocides and animal waste management plants. The strongest association for SGA was found with proximity to management animal waste plants. These results highlight the importance of further research on the relationship between proximity to industrial sites and the occurrence of adverse birth outcomes especially for the case of pharmaceutical and animal waste management activities.  相似文献   
902.
The compositional changes of saturates, aromatics, resins and asphaltenes (SARA) fractions in aqueous clay/oil microcosm experiments with a hydrocarbon-degrading microorganism community were analysed using Iatroscan. The clay mineral samples used in this study were organomontmorillonite, acid-activated montmorillonite and K, Ca, Zn and Cr montmorillonites produced by modifying the original montmorillonite sample. The evaluation and quantification of biodegradation and adsorption were carried out using a combination of the Iatroscan and gravimetric analysis. The SARA compositions in the presence of organomontmorillonite and acid-activated montmorillonite after incubation follow the same pattern in which the aromatic fraction is higher than the other fractions unlike in the presence of unmodified, K, Ca and Zn montmorillonites, where the saturates fraction is higher than the other fractions. Changes in SARA fractions due to biodegradation seemed to occur most in the presence of unmodified and calcium montmorillonites; hence, the removal of SARA fractions due to biodegradation was significant and enhanced in the presence of these two clay samples. However, biodegradation in the presence of organomontmorillonite and acid-activated and Cr montmorillonites was hindered. The study indicated that Cr montmorillonite adsorbed resins most, whereas Zn and K montmorillonites adsorbed aromatics most after incubation.  相似文献   
903.
Release of heavy metals into waterways without treatment can cause a significant threat to the environment. In this paper, we present a method of improving the removal of heavy metals by using Eichhornia crassipes roots (ECR) supported on a polymethyl methacrylate (PMMA) thin film. The functional groups of the synthesized PMMA sample were identified by Fourier transform infrared spectroscopy. ECR roots dried fine powder has a small size and large surface area. They contain many polyfunctional metal-binding sites for both cationic and anionic metal complexes. The results show that using 0.1 g of ECR, about 70 % of Cd present in the water was removed in 4 h; while under the same conditions, about 55 % of Ni was removed. The concentrations of Ni and Cd were measured by laser-induced breakdown spectroscopy, a promising technique for the elemental analysis of heavy metals.  相似文献   
904.
We provide a longer-term record of Hg wet deposition at two tropical latitude monitoring sites in Mexico, selected to provide regionally representative data. Weekly wet deposition samples were collected over 2 years, from September 2003 to November 2005. Based on this data set, we discuss the magnitude and seasonal variation of Hg in wet deposition and compare the results to other measurement sites and to several model estimates. With precipitation-weighted mean (PWM) concentrations of 8.2 and 7.9 ng L?1, respectively, during the sampling period from Sep 30 2003 to Oct 11 2005, and median weekly concentrations of 9.4?±?1 ng L?1 for both sites, the wet Hg concentrations and deposition at HD01 were much lower than those observed at the US Gulf Coast MDN sites while the wet Hg deposition at OA02 was much lower than most MDN sites, but somewhat similar to US MDN sites along the Pacific Coast. Based on the limited available data, we conclude that the approximately 30 % higher average precipitation at HD01 and roughly equal PWM concentrations lead to the higher deposition at HD01 versus OA02. We believe that these observations may offer scientists and modelers additional understanding of the depositional fluxes in the lower latitudes of North America.  相似文献   
905.
906.
Despite the extensive maritime transportation of Hazardous and Noxious Substances (HNS), there is a current lack of knowledge on the effects posed by HNS spills on the marine biota. Among the HNS identified as priority, acrylonitrile was selected to conduct ecotoxicological assays. We assessed the acute and subletal effects of acrylonitrile in seabass, followed by a recovery phase to simulate the conditions of a spill incident. The work aimed at testing a broad range of biological responses induced by acrylonitrile. Sublethal exposure to the highest two doses increased the fish mortality rate (8.3% and 25% mortality in 0.75 and 2 mg L−1 acrylonitrile concentrations), whereas no mortality were observed in control and 0.15 mg L−1 treatments. Additionally, important alterations at sub-individual level were observed. Acrylonitrile significantly induced the activities of Catalase– CAT and Glutathione S-Transferase – GST; and the levels of DNA damage were significantly increased. Conversely, Superoxide Dismutase– SOD – activity was found to be significantly inhibited and no effects were found on Lipid Peroxidation– LPO and ethoxyresorufin O-deethylase – EROD – activity. Following a 7 d recovery period, the levels of CAT, GST and EROD fell to levels at or below those in the control. In the 2 mg L−1 group, SOD remained at the levels found during exposure phase. This study has gathered essential information on the acute and subletal toxicity of acrylonitrile to seabass. It also demonstrated that 7 d recovery allowed a return of most endpoints to background levels. These data will be useful to assist relevant bodies in preparedness and response to HNS spills.  相似文献   
907.
Secondary pest outbreak is a counterintuitive ecological backlash of pesticide use in agriculture that takes place with the increase in abundance of a non-targeted pest species after pesticide application against a targeted pest species. Although the phenomenon was well recognized, its alternative causes are seldom considered. Outbreaks of the southern red mite Oligonychus ilicis are frequently reported in Brazilian coffee farms after the application of pyrethroid insecticides against the coffee leaf miner Leucoptera coffeella. Selectivity favoring the red mite against its main predatory mites is generally assumed as the outbreak cause, but this theory has never been tested. Here, we assessed the toxicity (and thus the selectivity) of deltamethrin against both mite species: the southern red mite and its phytoseid predator Amblyseius herbicolus. Additionally, behavioral avoidance and deltamethrin-induced hormesis were also tested as potential causes of red mite outbreak using free-choice behavioral walking bioassays with the predatory mite and life-table experiments with both mite species, respectively. Lethal toxicity bioassays indicated that the predatory mite was slightly more susceptible than its prey (1.5×), but in more robust demographic bioassays, the predator was three times more tolerant to deltamethrin than its prey, indicating that predator susceptibility to deltamethrin is not a cause of the reported outbreaks. The predator did not exhibit behavioral avoidance to deltamethrin; however insecticide-induced hormesis in the red mite led to its high population increase under low doses, which was not observed for the predatory mite. Therefore, deltamethrin-induced hormesis is a likely cause of the reported red mite outbreaks.  相似文献   
908.
Two compounds, 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO) are the main ingredients in a suite of explosive formulations that are being, or soon will be, fielded at military training ranges. We aim to understand the dissolution characteristics of DNAN and NTO and three insensitive muntions (IM) formulations that contain them. This information is needed to accurately predict the environmental fate of IM constituents, some of which may be toxic to people and the environment. We used Raman spectroscopy to identify the different constituents in the IM formulations and micro computed tomography to image their three-dimensional structure. These are the first three-dimensional images of detonated explosive particles.  相似文献   
909.
Borage, white mustard and phacelia, green manure plants currently used in agriculture to improve soil properties were cultivated for 10 wk on various polluted soils with metal(loid) concentrations representative of urban brownfields or polluted kitchen gardens. Metal(loid) bioavailability and ecotoxicity were measured in relation to soil characteristics before and after treatment. All the plants efficiently grow on the various polluted soils. But borage and mustard only are able to modify the soil characteristics and metal(loid) impact: soil respiration increased while ecotoxicity, bioaccessible lead and total metal(loid) quantities in soils can be decreased respectively by phytostabilization and phytoextraction mechanisms. These two plants could therefore be used for urban polluted soil refunctionalization. However, plant efficiency to improve soil quality strongly depends on soil characteristics.  相似文献   
910.
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