Analysis of Key Features of Non-Linear Behaviour Using Recurrence Quantification. Case Study: Urban Airborne Pollution at Mexico City

The use of recurrence plots have been extensively used in various fields. In this work, recurrence plots investigate the changes in the non-linear behaviour of urban air pollution using large datasets of raw data (hourly). This analysis has not been used before to extract information from large datasets for this type of non-linear problem. Two different approaches have been used to tackle this problem. The first approach is to show results according to monitoring network. The second approach is to show the results by particle type. This analysis shows the feasibility of using recurrence analysis for pollution monitoring and control.     

The environmental Kuznets curve and CO2 emissions in the USA

Environmental Science and Pollution Research - In this paper, we analyze the existence of the environmental Kuznets curve as reported by Kuznets (Am Econ Rev 5:1–28, 1955) by using the...     

Androgenic and antiandrogenic activities in water and sediment samples from the river Lambro, Italy, detected by yeast androgen screen and chemical analyses

The river Lambro is the most polluted tributary of the river Po in North Italy and was chosen as a representative water course discharging industrialized areas. Water and sediment samples of the river Lambro were investigated regarding the presence of endocrine disrupting compounds. A combined procedure was used consisting of solid-phase extraction and HPLC based fractionation of samples, of screening for (anti)androgenic activity using the yeast androgen screen (YAS) and of chemical analysis using HPLC-MS/MS and GC-MS. Androgenic and antiandrogenic activities were found in specific fractions of the water and sediment while the total extracts showed antiandrogenic activity only. The chemical analysis of the fractions and total extracts with antiandrogenic activities revealed the presence of compounds with suspected antiandrogenic potency such as bisphenol A, iprodione, nonylphenol, p,p'-DDE and tert-octylphenol but other unknown compounds contributed mainly to the observed antiandrogenic activities. The antiandrogenic load of the river Lambro ranged between 1.34 and 17.1 microM flutamide-equivalents and may pose a risk to aquatic environments. Future screenings for EDC in the environment that have the potential to interfere with reproduction of aquatic organisms should be extended to different modes of actions including (anti)androgenic ones.     

Concentrations of PCDD/PCDF in soil close to a secondary aluminum smelter

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) were analyzed in samples of the emissions from a secondary aluminum smelter (ALS) and soil samples around the plant. The purpose was to estimate the impact of the emissions on the surrounding environment.PCDD/F soil concentrations were higher in the proximity of the plant, exceeding the limit adopted in Italy in soils for green areas and residential uses and the upper limit of several reference concentrations. The most contaminated sites were less than 500 m from the plant and the dioxin concentration with the distance from the ALS.Principal component analysis (PCA) showed that emissions from the ALS were the source of PCDD/F contamination in the soils closest to the plant. Multivariate data analyses such as PCA are therefore useful to identify sources of emission causing contamination.     

Monitoring of water quality inflow and outflow of a farm in Italian Padana plain for rice cultivation: a case study of two years

Environmental Science and Pollution Research - Rice cultivation requires a large use of pesticides and nutrients to control weed proliferation and improve production. The water quality of four...     

Brominated flame retardants and organochlorines in the European environment using great tit eggs as a biomonitoring tool

Large-scale studies are essential to assess the emission patterns and spatial distribution of organohalogenated pollutants (OHPs) in the environment. Bird eggs have several advantages compared to other environmental media which have previously been used to map the distribution of OHPs. In this study, large-scale geographical variation in the occurrence of OHPs, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), was investigated throughout Europe using eggs of a terrestrial residential passerine species, the great tit (Parus major). Great tit eggs from 22 sampling sites, involving urban, rural and remote areas, in 14 European countries were collected and analysed (5-8 eggs per sampling site). The environmentally most important congeners/compounds of the analysed pollutants were detectable in all sampling locations. For PCBs, PBDEs and OCPs, no clear geographical contamination pattern was found. Sum PCB levels ranged from 143 ng/g lipid weight (lw) to 3660 ng/g lw. As expected, PCB concentrations were significantly higher in the sampled urban compared to the remote locations. However, the urban locations did not show significantly higher concentrations compared to the rural locations. Sum PBDEs ranged from 4.0 ng/g lw to 136 ng/g lw. PBDEs were significantly higher in the urbanized sampling locations compared to the other locations. The significant, positive correlation between PCB and PBDE concentrations suggests similar spatial exposure and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs ranging from 191 ng/g lw to 7830 ng/g lw) were detected in rural sampling locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local usage and contamination sources. The higher variance among sampling locations for the PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. To our knowledge, this is the first study in which bird eggs were used as a monitoring tool for OHPs on such a large geographical scale.     

Novel application of the CORAL software to model cytotoxicity of metal oxide nanoparticles to bacteria Escherichia coli

Convenient to apply and available on the Internet software CORAL (http://www.insilico.eu/CORAL) has been used to build up quantitative structure-activity relationships (QSAR) for prediction of cytotoxicity of metal oxide nanoparticles to bacteria Escherichia coli (minus logarithm of concentration for 50% effect pEC50). In this study six random splits of the data into the training and test set were examined. It has been shown that the CORAL provides a reliable tool that could be used to build up a QSAR of the pEC50.     

Enhancement of the CO(2) retention capacity of X zeolites by Na- and Cs-treatments

Adsorption of carbon dioxide on alkaline modified X zeolites was investigated by temperature programmed desorption (TPD) analysis of these materials previously saturated with CO(2) at 50, 100 and 200 degrees C. Parent X zeolite (in its sodium form) was treated with different sodium and cesium aqueous solutions, using both carbonates and hydroxides as precursors. The resulting materials were characterised by nitrogen physisorption, XRD, and NH(3)-TPD, in order to determine their morphological, crystallographic and chemical properties. Slight desilication phenomena were observed using hydroxides as precursors, whereas the treatment with Cs salts lead to higher crystallinity losses. Several successive adsorption-desorption cycles were carried out in order to check the regenerability of the adsorbents. Cesium-treated zeolites present higher carbon dioxide retention capacities than the sodium treated and than the parent material. When working with these Cs-modified materials, the desorption takes place mainly at temperatures between 250 and 400 degrees C, results of great practical interest, since it allows the use these kinds of materials for adsorption-desorption cycles. The evolution of the retention capacity with temperature is also markedly more positive for Cs-treated zeolite, especially when carbonate is used as the precursor. These materials maintain high retention capacities at 100 degrees C (10mg g(-1)) and even at 200 degrees C (3mg g(-1)), temperatures at which the most of the adsorbents are inactive.     

QSAR trout toxicity models on aromatic pesticides

The pesticides originally designed to kill target organisms are dangerous for many other wild species. Since they are applied directly to the environment, they can easily reach the water basins and the topsoil. A dataset of 125 aromatic pesticides with well-expressed aquatic toxicity towards trout was subjected to quantitative structure activity relationships (QSAR) analysis aimed to establish the relationship between their molecular structure and biological activity. A literature data for LC₅₀ concentration killing 50% of fish was used. In addition to the standard 2D-QSAR analysis, a comparative molecular field analysis (CoMFA) analysis considering the electrostatic and steric properties of the molecules was also performed. The CoMFA analysis helped the recognition of the steric interactions as playing an important role for aquatic toxicity. In addition, the transport properties and the stability of the compounds studied were also identified as important for their biological activity.