Affordability of residential water tariffs: Alternative measurement and explanatory factors in southern Spain

Using information on a basic or “lifeline” level of domestic water use obtained from a water demand function based on a Stone–Geary utility function, a minimum water threshold of 128 m³ per household per year was estimated in a sample of municipalities in Southern Spain. As a second objective, water affordability indexes were then calculated that relate the cost of such lifeline to average municipal income levels. The analysis of the factors behind the differences in that ratio across Andalusian municipalities shows that the relative cost of purchasing the lifeline appears inversely related to average income levels, revealing an element of regressivity in the component of water tariffs affecting the least superfluous part of the household’s consumption. The main policy recommendation would involve redesigning water tariffs in order to improve access for lower income households to an amount of water sufficient to cover their basic needs. The proposed methodology could be applied to other geographical areas, both from developed and from developing countries, in order to analyze the degree of progressivity of the water tariffs currently in effect and in order to guide the design of more equitable regulatory policies.     

Use of isoperibolic calorimetry for the study of the effect of water concentration,temperature and reactor venting on the rate of hydroxylamine thermal decomposition

Hydroxylamine, NH₂OH, thermal decomposition has been responsible for two serious accidents. However, its reactive behavior and the synergy of factors affecting the rate of its decomposition are not understood. In this work, isoperibolic calorimetric measurements were performed in a metal reactor, in the temperature range 130–150 °C, employing 30–80 ml solutions containing 1.4–20 g of pure hydroxylamine (2.8–40 g of the supplied reagent). The calorimetric measurements were performed in order to assess the effects that NH₂OH concentration, temperature and reactor venting has on NH₂OH rate of decomposition. The measurements showed that increased concentration or temperature, results in faster reactions and probably higher pressure generation per mass of reactant, with concentration having a more pronounced effect. However, when both factors work synergistically the result is dramatically worse in terms of reaction rate. The pressure generation is also different, thus indicating that different reaction pathways predominate each time. Venting the produced gases in stages resulted in the highest mass loss of the solution.     

Vertical and horizontal distributions of microbial abundances and enzymatic activities in propylene-glycol-affected soils

The natural microbial activity in the unsaturated soil is vital for protecting groundwater in areas where high loads of biodegradable contaminants are supplied to the surface, which usually is the case for airports using aircraft de-icing fluids (ADF) in the cold season. Horizontal and vertical distributions of microbial abundance were assessed along the western runway of Oslo Airport (Gardermoen, Norway) to monitor the effect of ADF dispersion with special reference to the component with the highest chemical oxygen demand (COD), propylene glycol (PG). Microbial abundance was evaluated by several biondicators: colony-forming units (CFU) of some physiological groups (aerobic and anaerobic heterotrophs and microscopic fungi), most probable numbers (MPN) of PG degraders, selected catabolic enzymatic activities (fluorescein diacetate (FDA) hydrolase, dehydrogenase, and β-glucosidase). High correlations were found between the enzymatic activities and microbial counts in vertical soil profiles. All microbial abundance indicators showed a steep drop in the first meter of soil depth. The vertical distribution of microbial abundance can be correlated by a decreasing exponential function of depth. The horizontal trend of microbial abundance (evaluated as total aerobic CFU, MPN of PG-degraders, and FDA hydrolase activity) assessed in the surface soil at an increasing distance from the runway is correlated negatively with the PG and COD loads, suggesting the relevance of other chemicals in the modulation of microbial growth. The possible role of potassium formate, component of runway de-icers, has been tested in the laboratory by using mixed cultures of Pseudomonas spp., obtained by enrichment with a selective PG medium from soil samples taken at the most contaminated area near the runway. The inhibitory effect of formate on the growth of PG degraders is proven by the reduction of biomass yield on PG in the presence of formate.     

Characterization and Properties of Hydrophilic Cellulose Acetate Propionate Derivative

The chemical modification of Acrylamidomethyl Cellulose Acetate Propionate (AMCAP) was carried out by radical addition of acrylic acid. The structural modification was confirmed with the aid of FTIR, MS and NMR techniques. Thermal properties of hydrophilic cellulose derivative (AMCAP–H₂O₂) such as glass transition (T_g 153 °C) and thermal stability (372.7 °C) were determined by DSC and TGA techniques, respectively. These thermal properties confirmed the introduction of carboxylic groups into AMCAP structure, which causes an impact in their properties. The AMCAP–H₂O₂ shows minor contact angle compared to AMCAP, giving a more hydrophilic characteristic, due to acrylic acid addition into the side chains of AMCAP polymer.     

Regional extinction of a conspicuous dorid nudibranch (Mollusca: Gastropoda) in California

Felimare californiensis (=Hypselodoris californiensis) was once common throughout the Southern California Bight (SCB) and California Channel Islands. This well-known shallow-water nudibranch, which specializes on dysideid sponges, has persisted for decades in Mexico, but in California disappeared from its entire range by 1984. Since reappearing in 2003, it has been found only at Santa Catalina Island, plus sightings of single individuals in 2011 at Santa Cruz Island and San Diego. The decline of F. californiensis in California was documented using published historical records, museum collections, unpublished field accounts, and images posted online. The loss of this emblematic species is unique among Californian nudibranchs, including (1) its congener Felimare porterae (=Mexichromis porterae), with which it appears to overlap in diet, and (2) opisthobranch species with similar historical geographic ranges and mode of development. The decline in F. californiensis is not predicted by warming trends and climate variation over the past 40 years, including the strong El Niño events of 1983 and 1998. Coastal pollution from the large human population in southern California may have impacted Dysidea amblia, the primary reported prey of F. californiensis. Historical overcollecting of the nudibranch and habitat loss through the development of major ports likely also contributed to its decline. Sightings since 2003 are consistent with a nascent recovery, as elements of water quality have improved in the SCB in recent decades.     

A new approach to in-situ determination of roadside particle emission factors of individual vehicles under conventional driving conditions

A method for continuous on-road measurements of particle number emissions for both diesel- and petrol-fuelled vehicles is presented. The setup allows the determination of particle number emission factors on an individual vehicle basis by the simultaneous measurement of CO₂ and particle concentrations. As an alternative to previous measurements on the kerbside, the sample is taken directly in the street, with the advantage of sampling in-situ within the exhaust plumes of passing vehicles, allowing the separation of the individual high-concentration plumes. The method was tested in two experiments that were conducted in the Gothenburg area. In the first study, which was performed at an urban roadside, we were able to determine particle emission factors from individual vehicles in a common car fleet passing the measurement site. The obtained emission factors were of the same order of magnitude (between 1.4 × 10¹² and 1.8 × 10¹⁴ particles km^?1) as values published in the recent literature for light duty vehicles. An additional on-road experiment was conducted at a rural road with four light duty reference vehicles (three of them petrol-powered and one diesel-powered) at driving speeds of 50 and 70 km h^?1, realised with different engine speeds. The results of the traffic emission studies show that the method is applicable provided that instruments with an adequate dynamic range are used and that the traffic is not too dense. In addition, the variability in particle emissions for a specified driving condition was estimated.     

Children's “peace with nature” festival — Assisi

The Festival described in this article won the Golden Ball Award for education of the Italian Academy of Lincei. Dr Maria Luisa Cohen, the author, was honoured with the Tree of Learning Award for 1988, by the Commission on Education and Training of the IUCN, for her services to environmental education and her promotion and participation in the Festival.     

Speciation of arsenic in plants by HPLC-HG-AFS: extraction optimisation on CRM materials and application to cultivated samples

A recently developed method for the determination of arsenic species (arsenite, arsenate, monomethylarsonate, MMAA, and dimethylarsinate, DMAA) has been applied to the study of arsenic speciation in plants. This method uses ion-exchange liquid chromatography coupled on-line to atomic fluorescence spectrometry through continuous hydride generation. Various extraction procedures have been studied in detail using three plant certified reference materials. None of the procedures tested revealed fully satisfying results with all kinds of plant samples; microwave assisted extraction with 0.3 mol dm-3 orthophosphoric acid was found to be the most convenient for dealing with terrestrial plants. Species stability appears good. This method was applied to real world cultivated plant parts. Arsenate appears to predominate in soils, roots and leaves; unidentified species (probably arsenosugars) play an important role (60%) in rice fruits. Carrot was found to be the most contaminated edible plant part, containing 1 mg kg-1 essentially as arsenate species. MMAA was detected in all soils and some plant parts especially shallots at low levels, whereas DMAA was found only in one soil sample and in hot pepper leaves. Arsenite is a minor component of all soils; it is also present in some plant parts at low levels. However, no evident relationships were found between As speciation in the various plant parts and much more detailed studies will be necessary to elucidate As behaviour in plants.     

The effectiveness of ESP (Electronic Stability Program) in reducing real life accidents

ESP (Electronic Stability Program) has recently been introduced onto the market in an effort to reduce the number and severity of loss-of-control automobile accidents. This reduction is expected to be particularly evident for accidents on roads with low friction (e.g., wet or icy conditions). This study aimed to evaluate the statistical effectiveness of ESP using data from accidents that occurred in Sweden during 2000 to 2002. To control for exposure, induced exposure methods were used, where ESP-sensitive to ESP-insensitive accidents and road conditions were matched in relation to cars equipped with and without ESP. Cars of similar, or in some cases identical, make and model were used to isolate the role of ESP. As predicted, the study showed a positive effect of ESP in circumstances where road surfaces have low friction. The overall effectiveness was 22.1 (+/-21) percent, while for accidents on wet roads, the effectiveness increased to 31.5 (+/-23.4) percent. On roads covered with ice and snow, the corresponding effectiveness was 38.2 (+/-26.1) percent. In addition, ESP was found to be effective for three different types of cars: small front-wheel drive; large front-wheel drive; and large rear-wheel drive.