Geochemical Distribution and Bioavailability of Heavy Metals and Oxalate in Street Sediments from Rio de Janeiro, Brazil: A Preliminary Investigation

As urbanisation accelerates within less-economically developed countries, populations in cities such as Rio de Janeiro are subject to numerous health risks relating to “heavy metal”, sewage and vehicle pollution. These risks apply especially to children, through inhalation and dermal contact with pollutant-rich street sediments that reflect contamination from atmospheric deposition and act as effective sinks for heavy metals and oxalates. To assess the nature and extent of these risks street sediments were collected from industrial, commercial, residential and recreational areas with varying traffic densities within Rio de Janeiro. A modified selective extraction procedure was used to study the geochemical partitioning and bioavailability of Fe, Mn, Zn, Cu, Cr, Ni, Pb and C₂O ₄ ⁻ . Oxalate partitioning has not been studied by traditional sequential methods and results from this procedure highlight the potential bioavailability of both oxalates and “heavy metals”, especially Pb and C₂O ₄ ⁻ in industrial and recreational areas.     

Alternative approaches to flood mitigation: a case study of Bangladesh

Floods were by far the most damaging type of natural disasters during the 1990s, in terms of both human impacts and socio-economic losses. Vulnerability to flooding disasters around the world is almost always differentiated by the socio-economic conditions of different income groups in the disaster area. In general, the poorer the income group (or the country) the more vulnerable it is likely to be to the adverse impacts of floods. The article argues that Bangladesh is the world's most flood-prone developing country in terms of the relative socio-economic impacts of floods. While conventional flood control strategies tend to be based on structural engineering approaches—such as the construction of large-scale embankments, diversion canals and dams—this article argues that more emphasis should be given to alternative, non-structural measures. The main lesson from recent flooding disasters in Bangladesh is that, in the absence of expensive structural measures, many non-structural ones can go a long way towards reducing vulnerability to and mitigating the impacts of floods.     

The meaning of mainland Portugal beaches and dunes’ psammophilic plant communities: a contribution to tourism management and nature conservation

Due to their position of interface between the sea and land, the flora and vegetation of coastal beaches and dunes, occupy ecologically extreme, sensitive, unique and valuable habitats. The occurrence of a large number of endemic taxa and specific plant associations endowed with key ecological services and adapted to a stressful and harsh environmental gradient, gives them a high interest for nature conservation and an important role in sustainable territorial planning. However, such ecosystems are vulnerable to the disruption caused by several anthropogenic sources. Among other global threat factors, the inevitable sea rise caused by climate change and, at a local scale, the non-negligible implications of trampling caused by disorderly coastal touristic exploitation, growing construction pressure in the littoral, and a seasonal population boom in late spring and in summer, plus all derivate forms of pollution, are threat factors to their integrity. Therefore, a correct planning of the touristic economic activities requires the understanding of the vegetation composition and spatial distribution patterns, intrinsically determined by their biogeographic context in the Euro-Siberian or Mediterranean Regions. This comprehensive work, based on a broad phytogeographic study, brings together disperse information on plant communities of the Portuguese sandy coasts (beaches and dunes), by analysing floristic compositions, chorology and ecological characteristics, and matching them with the “Nature 2000” network habitats. Resilience and vulnerability are also studied. In a nature conservation perspective, a positive balance (and a sustainable co-existence) between the preservation of natural values and human development in the Portuguese coast, will benefit with the integration of this knowledge in coastal planning and management activities.     

Comparative effects of oral exposure to 2, 4, 6-tribromophenol and decabromodiphenyl ether in Nile tilapia

Environmental Science and Pollution Research - Flame retardants are compounds added to a high diversity of polymers used in electronics and furniture to decrease the risk of combustion....     

Chemical,Morphological, Thermal and Technological Properties of Acetylated White Inhambu Starch

Journal of Polymers and the Environment - Starch is the main predominant food reserve in plants. Its characteristics stand out from other carbohydrates providing it with several industrial...     

Biodegradable chelating agents for industrial,domestic, and agricultural applications—a review

Aminopolycarboxylates, like ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), are chelating agents widely used in several industrial, agricultural, and domestic applications. However, the fact that they are not biodegradable leads to the presence of considerable amounts in aquatic systems, with serious environmental consequences. The replacement of these compounds by biodegradable alternatives has been the object of study in the last three decades. This paper reviews the most relevant studies towards the use of environmentally friendly chelating agents in a large number of applications: oxidative bleaching, detergents and cleaning compositions, scale prevention and reduction, remediation of soils, agriculture, electroplating, waste treatment, and biocides. Nitrilotriacetic acid (NTA), ethylenediaminedisuccinic acid (EDDS), and iminodisuccinic acid (IDS) are the most commonly suggested to replace the nonbiodegradable chelating agents. Depending on the application, the requirements for metal complexation might differ. Metal chelation ability of the most promising compounds [NTA, EDDS, IDS, methylglycinediacetic acid (MGDA), l-glutamic acid N,N-diacetic acid (GLDA), ethylenediamine-N,N′-diglutaric acid (EDDG), ethylenediamine-N,N′-dimalonic acid (EDDM), 3-hydroxy-2,2-iminodisuccinic acid (HIDS), 2-hydroxyethyliminodiacetic acid (HEIDA), pyridine-2,6-dicarboxylic acid (PDA)] with Fe, Mn, Cu, Pb, Cd, Zn, Ca, and Mg was simulated by computer calculations. The advantages or disadvantages of each compound for the most important applications were discussed.     

Wild meat trade over the last 45 years in the Peruvian Amazon

The trade in wild meat is an important economic component of rural people's livelihoods, but it has been perceived to be among the main causes of the decline of wildlife species. Recently, the COVID-19 pandemic has brought to light an additional concern of wildlife markets as a major human-health challenge. We analyzed data from the largest longitudinal monitoring (1973–2018) of the most important urban wild-meat markets in Iquitos, Peru, to examine the trends in and impacts of these markets on people's livelihoods. Over the last 45 years, wild meat sales increased at a rate of 6.4 t/year (SD 2.17), paralleling urban population growth. Wild meat sales were highest in 2018 (442 t), contributing US$2.6 million (0.76%) to the regional gross domestic product. Five species of ungulates and rodents accounted for 88.5% of the amount of biomass traded. Vulnerable and Endangered species represented 7.0% and 0.4% of individuals sold, respectively. Despite growth in sales, the contribution of wild meat to overall urban diet was constant: 1–2%/year of total meat consumed. This result was due to greater availability and higher consumption of cheaper meats (e.g., in 2018, poultry was 45.8% cheaper and was the most consumed meat) coupled with the lack of economic incentives to harvest wild meat species in rural areas. Most wild meat was sold salted or smoked, reducing the likelihood of foodborne diseases. Community-based wildlife management plans and the continued trade bans on primates and threatened taxa may avoid biodiversity loss. Considering the recent COVID-19 pandemic, future management plans should include potential viral hosts and regulation and enforcement of hygiene practices in wild-meat markets.     

Phosphorus mass balance and input load estimation from the wet and dry periods in tropical semiarid reservoirs

The dynamics of total phosphorus (TP) in 18 strategic reservoirs of the high-density reservoir network of the Brazilian semiarid was evaluated during the wet and dry periods for the past 12 years. Seasonal overlying concentrations presented no significant differences for about 90% of the reservoirs (p>0.05). This was attributed to a trade-off between the hydrological/limnological processes occurring in the two seasons. Then, a transient complete-mix mass balance model was applied with particular adaptations for the tropical semiarid reservoirs to estimate the TP load for each season. Because of the relatively well-mixed conditions and high hypolimnetic dissolved oxygen concentrations during the wet season, the wet load was assumed to represent the external TP load. On the other hand, because of the absence of reservoir inflow during the dry season, phosphorus release under anoxic sediment conditions and wind-induced resuspension under shallow water depths, the dry load was assumed to reflect the internal TP load. The maximum external loads were related to peak inflows, notably after drought periods. Consistently, the largest internal loads were obtained during the drought periods, when the reservoirs were shallower and more prone to phosphorus release and resuspension. By comparing the impact of the two input load types, the wet period load was predominant in 72% of the reservoirs. The areal phosphorus loads ranged from 0.66 to 7.29 gP m² year^?1, which were consistent with the literature, despite the very high density of reservoirs. Finally, power-law curves including data for all studied reservoirs were adjusted between the dry period load and volume, dry and wet period loads, wet period load and inflow, and total load and catchment area, resulting in satisfactory R² (0.84–0.98).

     

Ionic Dye Removal Using Solvent-Assisted Ionic Micellar Flocculation

Journal of Polymers and the Environment - The environmental impacts caused by dyes in industrial wastewater are incalculable, due to their adverse effects on the ecosystem and human life,...