A comparative study on the raw chitin and chitosan yields of common bio-waste from Philippine seafood

Environmental Science and Pollution Research - Bio-waste materials from aquatic species are alternative sources of chitin and chitosan—high-value natural biodegradable and biocompatible...     

Spatial PM2.5 mobile source impacts using a calibrated indicator method

Motor vehicles are major sources of fine particulate matter (PM_2.5), and the PM_2.5 from mobile vehicles is associated with adverse health effects. Traditional methods for estimating source impacts that employ receptor models are limited by the availability of observational data. To better estimate temporally and spatially resolved mobile source impacts on PM_2.5, we developed an approach based on a method that uses elemental carbon (EC), carbon monoxide (CO), and nitrogen oxide (NO_x) measurements as an indicator of mobile source impacts. We extended the original integrated mobile source indicator (IMSI) method in three aspects. First, we generated spatially resolved indicators using 24-hr average concentrations of EC, CO, and NO_x estimated at 4 km resolution by applying a method developed to fuse chemical transport model (Community Multiscale Air Quality Model [CMAQ]) simulations and observations. Second, we used spatially resolved emissions instead of county-level emissions in the IMSI formulation. Third, we spatially calibrated the unitless indicators to annually-averaged mobile source impacts estimated by the receptor model Chemical Mass Balance (CMB). Daily total mobile source impacts on PM_2.5, as well as separate gasoline and diesel vehicle impacts, were estimated at 12 km resolution from 2002 to 2008 and 4 km resolution from 2008 to 2010 for Georgia. The total mobile and separate vehicle source impacts compared well with daily CMB results, with high temporal correlation (e.g., R ranges from 0.59 to 0.88 for total mobile sources with 4 km resolution at nine locations). The total mobile source impacts had higher correlation and lower error than the separate gasoline and diesel sources when compared with observation-based CMB estimates. Overall, the enhanced approach provides spatially resolved mobile source impacts that are similar to observation-based estimates and can be used to improve assessment of health effects.

Implications: An approach is developed based on an integrated mobile source indicator method to estimate spatiotemporal PM_2.5 mobile source impacts. The approach employs three air pollutant concentration fields that are readily simulated at 4 and 12 km resolutions, and is calibrated using PM_2.5 source apportionment modeling results to generate daily mobile source impacts in the state of Georgia. The estimated source impacts can be used in investigations of traffic pollution and health.     

Profiling unauthorized natural resource users for better targeting of conservation interventions

Unauthorized use of natural resources is a key threat to many protected areas. Approaches to reducing this threat include law enforcement and integrated conservation and development (ICD) projects, but for such ICDs to be targeted effectively, it is important to understand who is illegally using which natural resources and why. The nature of unauthorized behavior makes it difficult to ascertain this information through direct questioning. Bwindi Impenetrable National Park, Uganda, has many ICD projects, including authorizing some local people to use certain nontimber forest resources from the park. However, despite over 25 years of ICD, unauthorized resource use continues. We used household surveys, indirect questioning (unmatched count technique), and focus group discussions to generate profiles of authorized and unauthorized resource users and to explore motivations for unauthorized activity. Overall, unauthorized resource use was most common among people from poor households who lived closest to the park boundary and farthest from roads and trading centers. Other motivations for unauthorized resource use included crop raiding by wild animals, inequity of revenue sharing, and lack of employment, factors that created resentment among the poorest communities. In some communities, benefits obtained from ICD were reported to be the greatest deterrents against unauthorized activity, although law enforcement ranked highest overall. Despite the sensitive nature of exploring unauthorized resource use, management‐relevant insights into the profiles and motivations of unauthorized resource users can be gained from a combination of survey techniques, as adopted here. To reduce unauthorized activity at Bwindi, we suggest ICD benefit the poorest people living in remote areas and near the park boundary by providing affordable alternative sources of forest products and addressing crop raiding. To prevent resentment from driving further unauthorized activity, ICDs should be managed transparently and equitably.     

Sustainability assessment of water governance alternatives: the case of Guanacaste Costa Rica

Many new forms of water governance are emerging in response to economic and social needs and wants, as well as water-related problems such as scarcity, injustice, and conflict. However, there is little evidence on how sustainable these governance regimes are, which would be critical for making progress toward sustainable and just water governance. In this article, we present the results of a transdisciplinary multi-criteria sustainability assessment of alternative governance regimes for Guanacaste Province, Costa Rica. The assessment specifies differences between sustainable and unsustainable governance regimes, while also pinpointing how the current water governance regime performs in comparison to those alternatives. The findings indicate that those governance regimes with just and deliberative stakeholder involvement, secure groundwater reserves, and healthy dry tropical ecosystems were considered sustainable and just. In contrast, the current state of water governance was found to be at high risk of digressing toward unsustainable systems where rural communities lack rights and influence, where economies favor agro-industry and high impact tourism at the expense of rural livelihoods, and where water scarcity overwhelms weak governance. This assessment study clarifies water sustainability goals, asserts the need for transformational change, and offers a pragmatic foundation for actions toward sustainable water governance.     

Joint toxicity of copper and diazinon during embryonic and larval development of the common South American toad,Rhinella arenarum

Copper (Cu) and diazinon are two widely distributed pollutants; they coexist in agro-ecosystems and cause toxicity to wild biota. This study proposes to analyse the joint toxicity of binary mixtures of Cu and diazinon on the early development of the South American toad, Rhinella arenarum by means of a standardised test. Cu was always more toxic than diazinon. Cu was more embryotoxic while the pesticide was more toxic during the larval exposure than during the embryonic period. The different Cu/diazinon mixtures proportions assayed were significantly less toxic than expected by additive effects. Thus, an antagonistic interaction pattern was observed. This pattern was independent of the assayed proportion, the exposure times and the exposure developmental periods. In the risk assessment analysis to establish water quality criteria, the joint toxicity should be considered at different ratios, exposure time and life period for a certain species, in order to preserve wild species.     

Degradation and mineralization of the emerging pharmaceutical pollutant sildenafil by ozone and UV radiation using response surface methodology

Environmental Science and Pollution Research - Pharmaceuticals and their degradation products which are present in wastewater and superficial waters are becoming an ecological issue. This research...     

‘We have a right to breathe clean air’: the emerging environmental justice movement against waste incineration in cement kilns in Spain

Waste is increasingly being used as an alternative to conventional fossil fuels in cement kilns worldwide. This has led to the emergence of socio-environmental conflicts in many countries in which local groups articulate a common struggle against the cement industry, a new target within the international anti-incineration movement. This case report aims at characterising this emerging movement against waste incineration in cement kilns in Spain and explores its main four discursive dimensions in relation to the concept of environmental justice. We argue that the movement against waste incineration in cement kilns is incipient and growing in Spain, and it uses a distinctive vocabulary to refer to the environmental justice dimension of the struggle.     

Evaluation of disinfectants in order to eliminate fungal contamination in computer keyboards of an integrated health center in Piauí, Brazil

This quantitative and qualitative study aimed to evaluate the level of fungal contamination in computer keyboards from an Integrated Health Center (IHC) at Piauí, Brazil, and to evaluate the efficacy of 50% sodium bicarbonate and 50% alcoholic vinegar solutions to eliminate these microorganisms. Ten keyboards from six sectors of the IHC were chosen randomly, and the collection was performed in three situations: (i) before of disinfection, (ii) after disinfection with solution of sodium bicarbonate, and (iii) after disinfection with solution of alcoholic vinegar. Samples were inoculated in Petri dishes with dextrose agar potato plus chloramphenicol and incubated at room temperature for 72 h. All keyboards were contaminated with opportunistic fungi, with Cladosporium cladosporioides (29.4%) being the most frequent species, followed by Curvularia lunata (17.6%) and Aspergillus niger, Alternaria alternata, and Curvularia clavata with 11.8% each. The two solutions were proven to be efficient in eliminating fungal contamination; however, the sodium bicarbonate solution caused esthetic damages in keyboards. In addition, this study is the first report of the antifungal activity of alcoholic vinegar in filamentous fungi. Based on our findings, we suggest a daily disinfection of keyboards with a 50% vinegar solution plus adequate hygiene from the hands of professionals before and after the use of the computer and its annexes, as key actions to reduce nosocomial infections, particularly in economically disadvantaged countries.     

Identifying the potential of governance regimes to aggravate or mitigate local water conflicts in regions threatened by climate change

There is a need for specific knowledge of what people can do to mitigate harmful water conflicts. This need is evident in the rural dry tropics of Central America where people face climate change impacts, inefficient water management, and social tension. To address this need, we investigated why some local water conflicts escalated to violence and why other potential conflicts were avoided in Guanacaste Province, Costa Rica. We used interviews, focus groups, and a stakeholder workshop to analyse five cases. We found that violent actions only occurred when rural groups opposed government agencies in settings without mediating leadership. With one exception in a circumstance aggravated over many years, water users did not take violent action against competing water users. Distrust, which has been formed by legacies of ineffective rural stakeholder engagement, diminished the credibility of water-related information used in decision processes and thus prolonged conflicts. Active community-based groups respected by both rural constituencies and government agencies helped some people avoid difficult conflicts. Self-organised groups in other areas struggled to address disputes in settings with contested property rights, high socio-economic inequality, and low human capital. Using insights from Guanacaste, we outline practical conflict mitigation strategies fitted to a range of local water governance contexts found in rural Central America. Results suggest the need for incorporating certain types of peace-building processes in water management and development. The study provides a foundation for policy-makers, water managers, and other stakeholders to more effectively manage water disputes and avoid harmful conflicts in challenging regions.