TiO₂-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: structures and quantities

This work investigates the physical-chemical evolution during artificial aging in water of four commercialized sunscreens containing TiO₂-based nanocomposites. Sunscreens were analyzed in terms of mineralogy and TiO₂ concentration. The residues formed after aging were characterized in size, shape, chemistry and surface properties. The results showed that a significant fraction of nano-TiO₂ residues was released from all sunscreens, despite their heterogeneous behaviors. A stable dispersion of submicronic aggregates of nanoparticles was generated, representing up to 38 w/w% of the amount of sunscreen, and containing up to 30% of the total nano-TiO₂ initially present in the creams. The stability of the dispersion was tested as a function of salt concentration, revealing that in seawater conditions, a major part of these nano-TiO₂ residues will aggregate and sediment. These results were put in perspective with consumption and life cycle of sunscreens to estimate the amount of nano-TiO₂ potentially released into AQUATIC environment.     

Future landfill emissions and the effect of final cover installation--a case study

Municipal solid waste (MSW) landfills are potential long-term sources of emissions. Hence, they need to be managed after closure until they do not pose a threat to humans or the environment. The case study on the Breitenau MSW landfill was performed to evaluate future emission levels for this site and to illustrate the effect of final cover installation with respect to long-term environmental risks. The methodology was based on a comprehensive assessment of the state of the landfill and included analysis of monitoring data, investigations of landfilled waste, and an evaluation of containment systems. A model to estimate future emission levels was established and site-specific predictions of leachate emissions were presented based on scenario analysis. The results are used to evaluate the future pollution potential of the landfill and to compare different aftercare concepts in view of long-term emissions. As some leachable substances became available for water flow during cover construction due to a change in the water flow pattern of the waste, a substantial increase in leachate concentrations could be observed at the site (e.g. concentrations of chloride increased from 200 to 800 mg/l and of ammonia-nitrogen from 140 to about 500 mg/l). A period of intensive flushing before the final cover installation could have reduced the amount of leachable substances within the landfill body and rapidly decreased the leachate concentrations to 11 mg Cl/l and 79 mg NH₄-N/l within 50 years. Contrarily, the minimization of water infiltration is associated with leachate concentrations in a high range for centuries (above 400 mg Cl/l and 200 mg NH₄-N/l) with low concomitant annual emission loads (below 12 kg/year of Cl or 9 kg/year of NH₄-N, respectively). However, an expected gradual decrease of barrier efficiency over time would be associated with higher emission loads of 50 kg of chloride and 30 kg of ammonia-nitrogen at the maximum, but a faster decrease of leachate concentration levels.     

Responses of a soil bacterium, Pseudomonas chlororaphis O6 to commercial metal oxide nanoparticles compared with responses to metal ions

The toxicity of commercially-available CuO and ZnO nanoparticles (NPs) to pathogenic bacteria was compared for a beneficial rhizosphere isolate, Pseudomonas chlororaphis O6. The NPs aggregated, released ions to different extents under the conditions used for bacterial exposure, and associated with bacterial cell surface. Bacterial surface charge was neutralized by NPs, dependent on pH. The CuO NPs were more toxic than the ZnO NPs. The negative surface charge on colloids of extracellular polymeric substances (EPS) was reduced by Cu ions but not by CuO NPs; the EPS protected cells from CuO NPs-toxicity. CuO NPs-toxicity was eliminated by a Cu ion chelator, suggesting that ion release was involved. Neither NPs released alkaline phosphatase from the cells’ periplasm, indicating minimal outer membrane damage. Accumulation of intracellular reactive oxygen species was correlated with CuO NPs lethality. Environmental deposition of NPs could create niches for ion release, with impacts on susceptible soil microbes.     

Ecological impacts of the N-viro biosolids land-application for wild blueberry (Vaccinium angustifolium. Ait) production in Nova Scotia

Land application of biosolids from processed sewage sludge may deteriorate soil, water, and plants. We investigated the impact of the N-Viro biosolids land-application on the quality of the soil water that moved through Orthic Humo-Ferric Podzols soil of Nova Scotia (NS) at the Wild Blueberry Research Institute, Debert, NS Canada. In addition, the response of major soilproperties and crop yield was also studied. Wild blueberry (Vaccinium angustifolium. Ait) was grown under irrigated and rainfed conditions in 2008 and 2009. Four experimental treatments including (i) NI: N-Viro irrigated, (ii) NR: N-Viro rainfed, (iii) FI: inorganic fertilizer irrigated, and (iv) FR: inorganic fertilizer rainfed (control) were replicated 4 times under randomized complete block design. Soil samples were collected at the end of each year and analyzed for changes in cation exchange capacity (CEC), soil organic matter (SOM), and pH.Soil water samples were collected four times during the study period from the suction cup lysimeters installed within and below crop root zone at 20 and 40 cm depths, respectively. The samples were analyzed for a range of water quality parameters including conductance, hardness, pH, macro- and micronutrients, and the infectious pathogens Escherichia coli (E. coli) and salmonella. Berries were harvested for fruit yield estimates. Irrigation significantly increased CEC during 2008 and the soil pH decreased from 4.93 (2008) to 4.79 (2009). There were significant influences of irrigation, fertilizer, and their interaction, in some cases, on most of the soil water quality parameters except on the infectious bacteria. No presence of E. coli or salmonella were observed in soil and water samples, reflecting the absence of these bacteria in biosolids used in this experiment. Nutrient concentration in the soil water samples collected from the four treatments were higher in the sequence NI > NR > FI > FR. The irrigation treatment had significant effect on the unripe fruit yield. We conclude that the comparable performance of N-Viro biosolids and the increasing prices of inorganic fertilizers would compel farmers to use economically available N-Viro biosolids that, coupled with the supplemental irrigation, did not deteriorate the studied soil properties, soil water quality, and the wild blueberry yield during this experiment.     

Is the reproduction of Donax trunculus affected by their sites of origin contrasted by their level of contamination?

The reproductive cycle of bivalves is regulated by several natural environmental factors but exposure to chemical pollutants can also interfere and may result in advanced or delayed spawning season. To our knowledge, the gametogenic cycle of the suspension-feeder bivalve Donax trunculus has not yet been used as biomonitoring tool in ecotoxicological surveys. The aim of this study was to examine over a year physiological reproductive endpoints (sex-ratio, gametogenic and energy reserve cycles) and biological indices (condition index, allometry) in D. trunculus originating from two sites differing by their level of contamination. Specimens were collected bimonthly from November 2008 to October 2009 from a polluted site (Radès Méliane) and a comparatively reference site (Sidi Jehmi) in the Gulf of Tunis (Tunisia). Five stages were depicted by histological examination of gonads: undifferentiated, developing, mature, spawn and spent. Differences in the gametogenic cycle according to the site of origin of bivalves were observed. The spawning period began in March and was maximum in May in bivalves from both sites, but the percentage of spawning animals was higher in the polluted site vs the reference site. The spawning period was shorter in animals from the polluted site comparatively to the reference site. Energy reserves (glycogen, lipids) were higher in March and May comparatively to the other studied periods in bivalves from both sites. Lower energy reserves levels were usually observed in animals from the polluted site compared to the reference site. Seasonal variations of the condition index were associated to the reproductive and nutritive status of bivalves. Differences in allometry were depicted between bivalves from both studied sites. If we try to link allometry, energy reserves and reproduction, it can be hypothesized that for bivalves from the reference site, energy reserves are allocated to gametogenesis and length growth. For bivalves from the polluted site, energy reserves could be devoted to tolerance to chemical stress and to reproductive processes. Therefore, D. trunculus appears as a suitable sentinel species for the assessment of the ecotoxicological risk of contaminants such as endocrine disruptors.     

Comparison of EDTA-enhanced phytoextraction and phytostabilisation strategies with Lolium perenne on a heavy metal contaminated soil

Phytoremediation is a promising and cost-effective strategy to manage heavy metal polluted sites. In this experiment, we compared simultaneously phytoextraction and phytostabilisation techniques on a Cd and Zn contaminated soil, through monitoring of plant accumulation and leaching. Lolium perenne plants were cultivated for 2 months under controlled environmental conditions in a 27.6 dm³-pot experiment allowing the collect of leachates. The heavy metal phytoextraction was promoted by adding Na-EDTA (0.5 g kg⁻¹ of soil) in watering solution. Phytostabilisation was assessed by mixing soil with steel shots (1%) before L. perenne sowing. Presence of plants exacerbated heavy metal leaching, by improving soil hydraulic conductivity. Use of EDTA for phytoextraction led to higher concentration of heavy metal in shoots. However, this higher heavy metal extraction was insufficient to satisfactory reduce the heavy metal content in soil, and led to important heavy metal leaching induced by EDTA. On the other hand, addition of steel shots efficiently decreased both Cd and Zn mobility, according to 0.01 M CaCl₂ extraction, and leaching. However, improvement of growth conditions by steel shots led to higher heavy metal mass in shoot tissues. Therefore, soil heavy metal mobility and plant metal uptake are not systematically positively correlated.     

The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe

A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2-44 kg N ha⁻¹ yr⁻¹) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate.     

Once there was a river: a benefit–cost analysis of rehabilitation of the Jordan River

The Jordan River is among the world’s most famous and culturally and historically significant waterways. The lower stretch of the river, however, has been a victim of development in a water scarce region, with current flows less than 5 % of historical levels. Furthermore, as it functions as an international border in a region of conflict, access to the river and its potential as a tourist attraction has been limited. Recently, there have been numerous calls for rehabilitation of the river. This study presents a first estimate of the economic benefits of such rehabilitation and compares them to the estimated costs. Identical contingent valuation method surveys were administered in Israel, Jordan, and the Palestinian Authority. Evidence from this study shows that, despite the large opportunity costs of increasing environmental flows, rehabilitation of the lower Jordan would produce positive net economic benefits. This is true even though the study estimated only the benefits to local populations, and not to international tourists or those outside the region. Net benefits are maximized when taking a regional, as opposed to strictly national, approach.     

A survey-based evaluation of community-based co-management of forest resources: a case study of Baishuijiang National Natural Reserve in China

Community-based co-management (CBCM) mechanisms for forest management have matured through the development of new economic analysis and common property theory. However, while many local CBCM mechanisms have been initiated in Chinese Natural Reserves, there are few objective, data-based evaluations of whether these mechanisms improve forest conservation and local livelihoods. This research uses Baishuijiang National Natural Reserve (BNNR) as a study case to evaluate China’s current CBCM mechanisms. The evaluation is based mainly on three criteria: efficiency, equality and sustainability of project operation. Survey data indicate that local CBCM mechanisms provide a wide-participation platform for local villagers, associated administration managers, research institutions and NGOs to join in forest resource protection work while improving local livelihood. CBCM projects have also facilitated a reduction in forest resource dependency, the improvement of household income and encouragement of local people to participate in forest resource protection. Our analysis suggests that most CBCM organizations have made progress in efficiency, equity and sustainability. However, further study should focus on how to deal with the lingering problems of inequity in responsibility and rights among CBCM committee members, poor distribution of benefits, insufficient program-design and management expertise, faulty information dissemination, and insufficient capital investment.     

Quantifying summed fullerene nC60 and related transformation products in water using LC LTQ Orbitrap MS and application to environmental samples

The application of engineered nanomaterials increases strongly. Development of analytical techniques and their application to environmental samples is essential for human and environmental risk assessment of the nanoparticles. The objective of this study was to develop a sensitive analytical method to quantify nC(60) in water, using accurate mass screening liquid chromatography-hybrid linear ion trap Orbitrap mass spectrometry. nC(60) can be transformed by oxidation, reduction and photochemical reaction. Therefore, the formation of some transformation products of nC(60) was studied as well. Finally, the developed analytical method was applied to surface water samples from several locations in the Netherlands. The developed method enabled to detect and quantify aqueous concentrations of the summed nC(60) and its transformation products as low as 5 ng/L. It was observed that nC(60) transformation products exceed quantities of the parent C(60). Despite the high sensitivity of the developed method, no nC(60) or transformation products were detected in an array of Dutch surface waters. This might be due to low emissions, losses in the aqueous phase by sedimentation, sorption or further transformation processes.