Urban atmospheric pollution: personal exposure versus fixed monitoring station measurements

We initiated the PETER (pedestrian environmental traffic pollutant exposure research) project to investigate pedestrians' exposure to traffic related atmospheric pollutants, based on data obtained with the collaboration of selected categories of pedestrian urban workers. We investigated relations between roadside personal exposure levels of volatile aromatic hydrocarbons (including benzene) and particulate matter <10 microm (PM10) among traffic police (n = 126) and parking wardens (n = 50) working in downtown Bologna, Italy. Data were collected from workshifts throughout four 1-week periods in different seasons of 2000-2001. For benzene and PM10, comparisons were made with measurements by fixed monitoring stations, and influence of localized traffic intensity and meteorological parameters was examined. Roadside personal exposure to benzene correlated more strongly with other volatile aromatic hydrocarbons (toluene, xylenes and ethylbenzene) than with PM10. Benzene and PM10 personal exposure levels were higher than fixed monitoring station values (both p<0.0001). At multivariate analysis, benzene and PM10 data from fixed monitoring stations both correlated with meteorological variables, and were also influenced by localized traffic intensity. Plausibly because of the downtown canyon-like streets, weather conditions (during a period of drought) only marginally affected benzene personal exposure, and moderately affected PM10 personal exposure. These findings reinforce the concept that urban atmospheric pollution data from fixed air monitoring stations cannot automatically be taken as indications of roadside exposures.     

Following a scented beetle: larval faeces as a key olfactory cue in host location of Stegobium paniceum (Coleoptera: Anobiidae) by Lariophagus distinguendus (Hymenoptera: Pteromalidae)

Lariophagus distinguendus (Hymenoptera: Pteromalidae) is a generalist solitary ectoparasitoid parasitising immature stages of at least 11 foodstuff beetles from five families, including species developing in seeds of Poaceae and Fabaceae. In this study, we tested the role of visual and olfactory stimuli affecting L. distinguendus host location in the trophic context of Stegobium paniceum (Coleoptera: Anobiidae) infesting chickpeas, Cicer arietinum (Fabales: Fabaceae). When either visual plus olfactory cues or olfactory cues alone were provided, S. paniceum-infested chickpeas were more attractive than uninfested chickpeas to naïve L. distinguendus females. Larval faeces of S. paniceum also evoked strong attraction to female wasps. Uninfested chickpeas covered with host faeces were preferred over uninfested ones without faeces, while infested chickpeas were as attractive as healthy chickpeas plus host faeces. Overall, results demonstrated that L. distinguendus females orient their host-seeking decisions mainly on the basis of faeces-borne olfactory stimuli. Further research is on-going to characterise the volatiles from S. paniceum larval faeces to evaluate their attractiveness towards L. distinguendus females.     

Do tephritid-induced fruit volatiles attract males of the fruit flies parasitoid Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)?

The braconid wasp Psyttalia concolor (Szépligeti) is an endoparasitoid of several tephritids of economic importance. Even if it has been reported that females of this species rely extensively on tephritid-induced fruit volatiles (TIFVs) during host location, no information is available on the behavioural role of TIFVs on males. Because P. concolor females mate only once, we hypothesized that the perception of TIFVs could be crucial for males, guiding them towards infested fruits on which they could find newly emerged females, thus raising the males’ chances to locate receptive females during their lifespan. On this basis, here we evaluate the attractiveness of synthetic TIFVs from two different trophic interactions, Ceratitis capitata–Malus domestica and Ceratitis capitata–Prunus persica towards P. concolor virgin males. The results showed that both fruit-mimicking blends, three synthetic apple-borne (1-butyl butyrate, 1-butyl hexanoate and 1-hexyl (E)-2-methylbutenoate) and four synthetic peach-borne (ethyl octanoate, nonanoic acid, decanoic acid and dodecanoic acid) compounds were found to attract males. Among these molecules, 1-butyl butyrate, 1-butyl hexanoate and decanoic acid also prolonged the time the males spent performing searching activities on the TIPV-treated surface. Because males probably use these volatiles mainly for sexual purposes, we believe that these chemicals could be classified as sexual kairomones.     

Tourist-beach protection in north-eastern Sicily (Italy)

Sicily is the largest island in the Mediterranean, and tourism represents the most important income in the regional budget. This is due to a mild climate, to its considerable archaeological and cultural heritage, but above all to the beaches, which host visitors for most of the year. Nevertheless, Sicily has no official Integrated Coastal Zone Management (ICZM) policy and also lacks an overall plan for coastal protection. In 2000, however, driven by the EU, a process of selection of projects based on objective parameters was initiated. Not all of these projects have had the expected results and some are yet to be completed. One of these is Giardini Naxos, Taormina beach, one of the main tourist resorts in Sicily. There, due both to the incorrect position of the port structure and to the rapidly increasing coastal urbanization (second homes, hotels and waterfront), a process of coastal erosion has started, the beach has disappeared, and the promenade has been damaged. To rebuild the shore in order to protect the structures behind it and to restore the coast for beach goers, a submerged barrier (like a reef) was designed to protect an artificial beach replenishment using local and remote sands, mined from the continental platform bottom and compatible both in terms of composition and grain size. Even though the results were excellent during the first stages of the project, towards the end, financial support disappeared and the funds were allocated to other projects. This experience in Giardini Naxos illustrates the ineffectiveness of defensive action in the absence of coastal planning that takes into account the sustainability of interventions on a regional basis both from a structural and an economic standpoint.     

Toxicity of leather tanning wastewater effluents in sea urchin early development and in marine microalgae

This study was designed to investigate the composition and the toxicity of leather tanning wastewater and conditioned sludge collected at the leather tanning wastewater treatment plant (CODISO) located in Solofra, Avellino (Southern Italy). Samples were analyzed for their conventional parameters (COD, TSS, chromium and ammonia) and for metal content. Effluent samples included raw wastewater, and samples collected following coagulation/flocculation process and biological treatment. A set of toxicity endpoints were tested using sea urchin and marine microalgal bioassays by evaluating acute embryotoxicity, developmental defects, changes in sperm fertilization success and transmissible damage from sperm to the offspring, and changes in algal growth rate. Dose-related toxicity to sea urchin embryogenesis and sperm fertilization success was exerted by effluent or sludge samples according to the following rank: conditioned sludge > coagulated effluent > or = raw influent > effluent from biological treatment. Offspring quality was not affected by sperm exposure to any wastewater or to sludge samples. Algal growth was inhibited by raw or coagulated effluent to a similar extent and, again, the effluent from the biological treatment resulted in a decreased toxicity. The results suggest that coagulated effluent and conditioned sludge result in higher toxicity than raw influent in sea urchin embryos and sperm, whereas the biological wastewater treatment of coagulated effluent, in both sea urchins and algae, cause a substantial improvement of wastewater quality. Hence a final biological wastewater treatment should be operated to minimize any environmental damage from tannery wastewater.     

Environmental fate of triasulfuron in soils amended with municipal waste compost

The amendment of soil with compost may significantly influence the mobility and persistence of pesticides and thus affect their environmental fate. Factors like adsorption, kinetics, and rate of degradation of pesticides could be altered in amended soils. The aim of this study was to determine the effects of the addition of compost made from source-separated municipal waste and green waste, on the fate of triasulfuron [(2-(2-chloroethoxy)-N-[[4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide], a sulfonylurea herbicide used in postemergence treatment of cereals. Two native soils with low organic matter content were used. A series of analyses was performed to evaluate the adsorption and degradation of the herbicide in soil and in solution after the addition of compost and compost-extracted organic fractions, namely humic acids (HA), fulvic acids (FA), and hydrophobic dissolved organic matter (HoDOM). Results have shown that the adsorption of triasulfuron to soil increases in the presence of compost, and that the HA and HoDOM fractions are mainly responsible for this increase. Hydrophobic dissolved organic matter applied to the soils underwent sorption reactions with the soils, and in the sorbed state, served to increase the adsorption capacity of the soil for triasulfuron. The rate of hydrolysis of triasulfuron in solution was significantly higher at acidic pH and the presence of organic matter fractions extracted from compost also slightly increased the rate of hydrolysis. The rate of degradation in amended and nonamended soils is explained by a two-stage degradation kinetics. During the initial phase, although triasulfuron degradation was rapid with a half-life of approximately 30 d, the presence of compost and HoDOM was found to slightly reduce the rate of degradation with respect to that in nonamended soil.     

Selenite precipitation by a rhizospheric strain of Stenotrophomonas sp. isolated from the root system of Astragalus bisulcatus: a biotechnological perspective

A bacterial strain (SeITE02), related to the species Stenotrophomonas maltophilia and resistant to selenite (SeIV) up to 50 mM in the growth medium, was isolated from rhizospheric soil of a selenium hyperaccumulator plant, the legume Astragalus bisulcatus. The influence of SeIV on the active growth of this Se-tolerant bacterial strain has been investigated in oxic conditions, along with the isolate's ability to reduce selenite to elemental selenium (Se(0)). Interestingly, concentrations of 0.5 mM SeIV were wholly reduced by strain SeITE02 in liquid culture within 52 h. Moreover, 87% of SeIV added to the growth medium at the initial concentration of 2.0 mM underwent again reduction in 120 h. Actually, a selenite-mediated induction of a sort of adaptive response to detrimental SeIV effects magnified the efficiency of SeITE02 in reducing this toxic oxyanion. Furthermore, the SeIV influence on cell morphology of strain SeITE02 was evidenced by phase-contrast and electron microscopy analyses. In particular, transmission electron microscopy (TEM)-energy-dispersive X-ray (EDX) analysis of S. maltophilia strain SeITE02, grown in presence of SeIV, showed electron-dense Se(0) granules either in the cell cytoplasm or in the extracellular space. Therefore, the capability of strain SeITE02 to quickly reduce soluble and harmful SeIV to insoluble and unavailable Se(0) may be looked at as a promising exploitable option for the setup of low-cost biological treatments tailored to manage contamination in selenium-laden effluents.