Element contents and food safety of water spinach (Ipomoea aquatica Forssk.) cultivated with wastewater in Hanoi, Vietnam

Extensive aquatic or semi-aquatic production of water spinach (Ipomoea aquatica Forssk.) for human consumption takes place in Southeast Asia. The aim of this study was to assess the concentrations of 38 elements in soil and water spinach cultivated under different degrees of wastewater exposure in Hanoi, Vietnam. The results showed no effect of wastewater use on the overall element concentrations in soil and water spinach. Mean soil concentrations for selected potentially toxic elements at the studied field sites had the following ranges 9.11–18.7 As, 0.333–0.667 Cd, 10.8–14.5 Co, 68–122 Cr, 34.0–62.1 Cu, 29.9–52.8 Ni, 32.5–67.4 Pb, 0.578–0.765 Tl and 99–189 Zn mg kg⁻¹ dry weight (d.w.). In all samples Cd, Pb and Zn soil concentrations were below the Vietnamese Guideline Values (TCVN 7209-2002) for agricultural soils whereas As and Cu exceeded the guideline values. Maximum site element concentrations in water spinach were 0.139 As, 0.032 Cd, 0.135 Cr, 2.01 Cu, 39.1 Fe, 57.3 Mn, 0.16 Ni, 0.189 Pb and 6.01 Zn mg kg⁻¹ fresh weight (f.w.). The site and soil content of organic carbon were found to have high influence on the water spinach element concentrations whereas soil pH and the total soil element concentrations were of less importance. The estimated average daily intake of As, Cd, Cu, Fe, Pb and Zn for adult Vietnamese consumers amounts to <11% of the maximum tolerable intake proposed by FAO/WHO for each element. It is assessed that the occurrence of the investigated elements in water spinach will pose low health risk for the consumers.     

Noise mapping of densely populated neighborhoods—example of Copacabana, Rio de Janeiro—Brazil

Copacabana is one of the most famous neighborhoods of the city of Rio de Janeiro/Brazil but suffers from a high inhabitant density. One of the many environmental problems faced is related to noise pollution. In order to assess not only the noise levels, to which the population is exposed, but also to quantify the influence of architectural aspects, the paper presents the steps taken towards a simulation of the noise emission and propagation in this area. The results of the simulation are compared to measurements in different locations and daily-hours. The discrepancies are analyzed and the methodology is discussed in view of its application to a huge urban center like the city of Rio de Janeiro.     

Kriging and Bilinear Methods for Estimating Spatial Pattern of Atmospheric Pollutants

Two statistical methods to reconstruct the spatial pattern ofenvironmental data are compared: the Kriging and the Bilinear.The comparison is performed by evaluating two differentcharacteristics of the methods: the interpolation and the estimation. The Kriging method is demonstrated to be better thanthe Bilinear regarding all the statistics studied, although thedifferences are not very significant. Especially, the Kriging ismore efficient than the Bilinear in the reconstruction of peakvalues and it does not extrapolate local trends. The methods areapplied to a set of environmental data measured in an urban area.     

Lethal effects of abamectin on the aquatic organisms Daphnia similis, Chironomus xanthus and Danio rerio

Abamectin is used as an acaricide and insecticide for fruits, vegetables and ornamental plants, as well as a parasiticide for animals. One of the major problems of applying pesticides to crops is the likelihood of contaminating aquatic ecosystems by drift or runoff. Therefore, toxicity tests in the laboratory are important tools to predict the effects of chemical substances in aquatic ecosystems. The aim of this study was to assess the potential hazards of abamectin to the freshwater biota and consequently the possible losses of ecological services in contaminated water bodies. For this purpose, we identified the toxicity of abamectin on daphnids, insects and fish. Abamectin was highly toxic, with an EC₅₀ 48 h for Daphnia similis of 5.1 ng L⁻¹, LC₅₀ 96 h for Chironomus xanthus of 2.67 μg L⁻¹ and LC₅₀ 48 h for Danio rerio of 33 μg L⁻¹.     

Of Catholicism,Forest and Management: An Analysis of Imaginaries in the Discussion of the Native Forest Law in Chile

The relationship between media and the construction of environmental policy has been studied acutely in the Global North. However, less attention has been paid to deeper cultural symbols displayed in public policy discussions in the Global South. Through qualitative examination of 100 letters to the editor (LTE) of the Chilean newspaper, El Mercurio, this study examined the imaginaries in the public discussion of the Native Forest Policy in Chile. Although such a discussion was often framed as a technical debate, the letters to El Mercurio were embedded within Catholic imaginaries, condensed into two main sets. The first one constructed forests as endangered due to human action and called for immediate protection, contending that humans shall not destroy God's creation. The second set depicted a degraded forest in need of rational management to satisfy the needs of God's children. This study suggests that, in a mediated public discussion, religion might play an important role in communicating environmental issues. This work contributes to our understanding of environmental imaginaries and discourses in the context of environmental controversies, to the understanding of the functions of the LTE, and to the social construction of forest policy in recent post-autocratic regimes.     

Ecotoxicological effects of sediments from Mar Piccolo,South Italy: toxicity testing with organisms from different trophic levels

The Mar Piccolo of Taranto (Ionian Sea, Southern Italy) is a semi-enclosed and strongly polluted basin. For decades, it has been subjected to different anthropogenic impacts. These stressors caused severe sediments contamination with high concentration of different pollutants (PAHs, PCB, heavy metals). In order to assess the current status of sediments contamination, an ecotoxicological investigation combined with chemical analysis (heavy metals, PAH, and PCB) has been performed. In order to derive ecologically relevant conclusions, a multiorganisms and multiend-points approach has been applied, exposing organisms from different trophic levels to elutriate and whole sediment. The battery of bioassays consists of a microalgal growth inhibition test (Dunaliella tertiolecta), acute and sublethal assays (end-points: mortality, immobilization and swimming speed alteration) on crustaceans larvae and juveniles, and rotifers (Amphibalanus amphitrite, Artemia salina, Corophium insidiosum and Brachionus plicatilis), and embryotoxicity test on echinoderms (Paracentrotus lividus). Considering the high levels of sediment contamination highlighted from chemical analysis, an unexpected very low toxic effect was observed, even considering the sublethal end-point (larval swimming speed alteration). The results of this study suggest a very complex contaminants dynamic in the Mar Piccolo sediments that, despite a strong level of contamination, seems to not affect in a proportional manner the biological compartment.     

Behaviour of arsenic in forested catchments following a high-pollution period

Due to high availability of adsorption sites, forested catchments could be net sinks for pollutant arsenic both during the period of increasing and decreasing pollution. We tested this hypothesis along a north-south pollution gradient in spruce die-back affected areas of Central Europe. For two water years (2007-2008), we monitored As fluxes via spruce-canopy throughfall, open-area precipitation, and runoff in four headwater catchments (Czech Republic). Since 1980, atmospheric As inputs decreased 26 times in the north, and 13 times in the south. Arsenic export by runoff was similar to atmospheric inputs at three sites, resulting in a near-zero As mass balance. One site exhibited a net export of As (2.2 g ha⁻¹ yr⁻¹). In contrast, the preceding period (1995-2006) showed much higher As fluxes, and higher As export. Czech catchments do not serve as net sinks of atmospheric As. A considerable proportion of old industrial arsenic is flushed out of the soil.     

Image analysis application for the study of activated sludge floc size during the treatment of synthetic and real fishery wastewaters

Background, aim, and scope  

Fishery wastewater treatment can be compromised due to seasonal production. The use of sequencing batch reactors is not completely successful, despite flexibility being one of the principal advantages. Most research on activated sludge is performed using synthetic wastewater to ensure a stable and constant feed. The current work compared biomass morphology and settling ability using image analysis of synthetic and real fishery wastewaters, with and without NaCl addition.     

Inclusive education for children with disabilities in a refugee camp

Children in refugee camps, and particularly those with disabilities, face unique challenges in accessing education and are at high risk of being marginalised. Best practices suggest that main-streaming is the optimal strategy for serving students with disabilities. This study examines the extent to which mainstreaming in a refugee camp helps to promote children's prosocial behaviours, taking into account their emotional and behavioural problems. In Kakuma Refugee Camp, Kenya, researchers collected data from the parents of children currently enrolled in special needs education centres (n=65) and from those formerly enrolled at these facilities who transitioned to mainstream classrooms (n=81). Children in mainstream schools functioned better in terms of prosocial behaviours, but this relationship disappeared when factoring in children's emotional and behavioural difficulties. In the context of a refugee camp, mainstreaming alone is not likely to help children's psychosocial and educational functioning, which requires dedicated supports, appropriate facilities and infrastructure, and a dual focus on disability-specific and disability-inclusive initiatives.