Formation of bound residues by naphthalene and cis-naphthalene-1,2-dihydrodiol

The formation of bound residues by naphthalene and its metabolite, cis-naphthalene-1,2-dihydrodiol, in a sediment (1% OC), a silty loam soil (2.9% OC) and a peat (26% OC) was examined. The experiments were carried out under both sterile and nonsterile conditions for up to 35 days. The samples containing bound contaminant were hydrolyzed at an alkaline pH and fractionated using 3,000 and 500 Da molecular weight cutoff ultrafiltration membranes in series. The results for all the geosorbents examined showed that bound residue formation is low for naphthalene and between 5 and 20 times higher for the metabolite. The amount of bound residues released by hydrolysis was higher for the metabolite than for the parent compound for all the samples. The molecular weight distribution of bound radioactivity after hydrolysis showed binding to the high molecular weight components of the sediment organic matter and to the low molecular weight components for soil and peat organic matter when incubated with cis-naphthalene-1,2-dihydrodiol. Experiments performed with naphthalene-UL-(14)C showed larger amounts of bound residue found than in experiments with naphthalene-1-(14)C.     

Health risk assessment of emissions of dioxins and furans from a municipal waste incinerator: comparison with other emission sources

The aim of this study was to calculate the incremental lifetime-risk to dioxins and furans (PCDD/Fs) for the population living in the surroundings of a municipal solid waste incinerator (MSWI), as well as to establish the potential reduction on human health risks as a consequence of the adaptation to the EU legislation on pollutant emissions from the MSWI stack. Analytical and modelled results were obtained. PCDD/F concentrations in environmental media were determined by means of a simple-compartment-multimedia model (air-soil-vegetation model). Predicted and measured PCDD/F concentrations in soils and vegetation were compared, and the effects of MSWI emissions in the environmental media were determined. Human health risks due to PCDD/F emissions from the MSWI were also estimated based on I-TEQ measured and modelled in various environmental media. Cancer risks due to PCDD/F emissions of the plant were 1.07E-07 and 3.08E-09, before and after installation of the clean air system, respectively. On the other hand, cancer risks due to other PCDD/F emission sources in the area were 5.54E-06 and 1.86E-06. Total PCDD/F cancer risks (including those from diet) for the population living in the vicinity of the MSWI were 1.3E-04 and 4.25E-05, respectively (67.6% of reduction). Hazard ratio for total PCDD/F exposure (including diet) decreased during the last 5 years from 1.16 to 0.38. The above data show that other emission sources of PCDD/Fs also have a notable environmental impact on the area under direct influence of the MSWI.     

Analysis of the cost-effectiveness for ecosystem service provision and rural income generation: a comparison of three different programs in Southern Ecuador

In recent years, new tools for funding nature conservation have been designed. Because poverty is often significant in areas with high biodiversity, the improvement of local livelihoods is frequently considered as a secondary goal of new financing mechanisms besides nature conservation. The buffer zone of the Podocarpus National Park in Ecuador is such a high biodiversity zone. In this paper, we compare the cost-effectiveness and development potential of three different mechanisms to finance nature conservation implemented in this buffer zone, namely (a) an organic coffee label, (b) the Socio Bosque Program, a nationwide payment scheme for private forest conservation, and (c) FORAGUA, a regional water fund. This paper describes the functioning and the scope of the mechanisms and analyses their environmental and socio-economic impacts which are compared to the total costs. Results show that the water fund has the highest additionality in ecosystem service provision, while the payment scheme is the most cost-effective both for current as for increased ecosystem service provision and for extra rural job creation. Organic coffee certification has the highest positive impact on rural income creation.     

Per- and polyfluorinated compounds (PFCs) in house dust and indoor air in Catalonia, Spain: implications for human exposure

A total of 27 per- and polyfluorinated compounds (PFCs) were determined in both house dust (n = 10) and indoor air (n = 10) from selected homes in Catalonia, Spain. Concentrations were found to be similar or lower than those previously reported for household microenvironments in other countries. Ten PFCs were detected in all house dust samples. The highest mean concentrations corresponded to perfluorodecanoic acid (PFDA) and perfluorononanoic acid (PFNA), 10.7 ng/g (median: 1.5 ng/g) and 10.4 ng/g (median: 5.4 ng/g), respectively, while the 8:2 fluorotelomer alcohol (FTOH) was the dominating neutral PFC at a concentration of 0.41 ng/g (median: 0.35 ng/g). The indoor air was dominated by the FTOHs, especially the 8:2 FTOH at a mean (median) concentration of 51 pg/m³ (median: 42 pg/m³). A limited number of ionic PFCs were also detected in the indoor air samples. Daily intakes of PFCs were estimated for average and worst case scenarios of human exposure from indoor sources. For toddlers, this resulted in average intakes of ∑ ionic PFCs of 4.9 ng/day (0.33 ng/kg_bw/day for a 15 kg toddlers) and ∑ neutral PFCs of 0.072 ng/day (0.005 ng/kg_bw/day) from house dust. For adults, the average daily intakes of dust were 3.6 and 0.053 ng/day (0.05 and 0.001 ng/kg_bw/day for a 70 kg adult) for ∑ ionic and ∑ neutral PFCs, respectively. The average daily inhalation of ∑ neutral PFCs was estimated to be 0.9 and 1.3 ng/day (0.06 and 0.02 ng/kg_bw/day) for toddlers and adults, respectively. For PFOS, the main ionic PFC detected in indoor air samples, the median intakes (based on those samples where PFOS was detected), resulted in indoor exposures of 0.06 and 0.11 ng/day (0.004 and 0.002 ng/kg_bw/day) for toddlers and adults, respectively. Based on previous studies on dietary intake and drinking water consumption, both house dust and indoor air contribute significantly less to PFC exposure within this population.     

Solar radiation synthetic series for power purchase agreements

The present paper proposes a methodology based on the implementation and assessment of autoregressive (AR) solar radiation models for generating synthetic series and providing guidance on bidding strategies for power purchase agreements. The work considered conventional and periodic AR models with different lag orders, assessing the models against real solar radiation measurements. The synthetic series generation process developed 1000 1-year monthly solar radiation scenarios that were later employed for simulating electric energy production and power purchase agreement models. This application allowed one to evaluate the risk associated with the energy supply security, supporting bidding strategies in energy auctions. A real study case is also illustrated in detail, referring to a spot in the Brazilian best irradiance area.

     

The contribution of non‐timber forest products towards sustainable rural development: The case of Candelilla wax from the Chihuahuan Desert in Mexico

The promotion of development projects based on the commercialization of non‐timber forest products has increased in recent decades, showing a positive contribution to rural development; yet it has led to controversial approaches in resource preservation. This paper examines the case of Candelilla wax from the Chihuahuan Desert in northern Mexico, identifying its potential contribution to poverty alleviation in marginal areas, and its unique opportunity to access potential markets of a wide variety of industries all around the world. In this paper, the authors base their analysis on three main aspects: social, economic and environmental. Potential benefits that could be obtained from the collaboration of private institutions, development organizations, policymakers and rural producers through integrated rural development projects are featured.     

Human health risk assessment of environmental and dietary exposure to natural radionuclides in the Catalan stretch of the Ebro River, Spain

This study was aimed at assessing the levels of ²¹⁰Pb and ²¹⁰Po concentrations as well as gross alpha and beta activities in environmental monitors from the Catalan stretch of the Ebro River (Spain), potentially influenced by the presence of sediments with high concentrations of ²³⁸U and its decay chain daughters in the Flix reservoir. The chronic daily intake of ²¹⁰Pb and ²¹⁰Po through ingestion and inhalation of soils was evaluated, and the derived non-carcinogenic and carcinogenic risks were characterized. The low concentration of radioisotopes in soils resulted in a negligible annual effective dose. The levels of ²¹⁰Pb and ²¹⁰Po were determined in various groups of highly consumed food (fish and seafood, vegetables, fruits, and rice), and their dietary intake was calculated. The annual effective dose for the adult people from food intake was estimated in 3.3 × 10^???2 mSv, mostly due to ²¹⁰Po. Overall, the current radioactivity levels in the Catalan stretch of the Ebro River should not mean any additional health risk for the population living nearby. However, an integral assessment of the risks derived from exposure to other pollutants (e.g., metals and organochlorine compounds) jointly with radionuclides could be of great interest.     

Efficient Transmission of an Introduced Pathogen Via an Ancient Insect-Fungus Association

 In Cupressus sempervirens the association between seed insects and tree pathogens has resulted in optimal exploitation of the cones. A fungus-infected cone can be inhabited by the nymphs of a true seed bug (Orsillus maculatus), the adults of which may carry a heavy spore load at emergence. Cones are infected when eggs are laid within the cone, most frequently via the emergence holes of a seed wasp (Megastigmus wachtli). This symbiotic association evolved with the nonaggressive fungus Pestalotiopsis funerea within the natural range of the cypress. When the aggressive cypress canker disease (Seiridium cardinale) was introduced into Europe, it was transmitted by O. maculatus to cones usually colonized by Pestalotiopsis funerea, with disastrous consequences for the regeneration and survival of C. sempervirens in the entire Mediterranean area. Received: 30 November 1998 / Accepted in revised form: 17 May 1999     

Integration studies on a two-stage fermentation process for the production of biohydrogen

Fermentation of biomass residues and second generation biomasses is potentially a way to enable a sustainable production of hydrogen. Simulation models which calculate mass and energy balances, developed with Aspen Plus^®, are used to integrate the process steps necessary to produce pure hydrogen from biomass in a 2-stage fermentation process. Process and heat integration are introduced to reduce the high water and heat demand of the process, connected to the low substrate concentrations in the involved process streams. The results show that the recirculation of process effluents, together with the use of properly designed heat exchangers, can reduce the water and heat demand up to 90% from a non-integrated process, but is also subject to restrictions due to an increase in osmolality in the system.