Chronic effects of vapour phase di-n-butyl phthalate (DBP) on six plant species

A fumigation experiment was performed in which six plant species representing the European flora were exposed to a range of DBP concentrations. Controlled amounts of DBP-saturated air were injected into the ingoing air-streams of plant fumigation chambers, maintaining constant concentrations there for a period of up to 76 days. The target concentrations were a control, 0.8, 1.5, 3.5, and 10.0 microg m(-3). The variation in sensitivity between plant species to atmospheric DBP was quantified on the basis of whole plant biomass in order to derive no-observed-effect-concentrations (NOECs). Significant dose-response relationships, based on realised concentrations, were thus derived using non-linear regression, resulting in NOECs of 0.51 microg m(-3) for Trifolium repens, 0.96 microg m(-3) for Brassica campestris, 1.87 microg m(-3) for Phaseolus vulgaris and 2.21 microg m(-3) for Plantago major. A significant effect was also observed for Holcus lanatus at 12.4 microg m(-3) DBP, but due to the variation at lower levels of DBP exposure, no dose-response relationship could be derived. No significant effect on growth of current year needles in Picea abies was observed, even at the highest level of DBP, 13.7 microg m(-3). Based on statistical extrapolation according to Aldenberg and Slob [Ecotox. Environ. Safety, 25 (1993) 48], an overall predicted no-effect concentration (PNEC) for the plant-atmosphere compartment of 0.33 microg m(-3) DBP was calculated. The PNEC was calculated using the mean and standard deviation of the NOEC for four of the tested species and an extrapolation factor. In addition to changes in leaf colour, leaf crinkling and growth reduction, a number of not quantified observations are described, indicating that DBP affects the physiology as well as the morphology of these species.     

Direct VUV photolysis of chlorinated methanes and their mixtures in a nitrogen stream

The gas-phase decomposition of CCl(4), CHCl(3) and CH(2)Cl(2) and their binary mixtures was studied in a flow-type reactor in a nitrogen gas stream, using a low-pressure mercury vapour lamp covered with a high-purity silica quartz sleeve. The 184.9 nm vacuum-ultraviolet (VUV) light emitted is able to rupture the C-Cl bond in these target substances. For H-containing compounds, the decomposition takes place not only by direct photolysis, but also by H abstraction by .Cl formed during the direct photolysis of the target substances. The relative contributions of direct photolysis and .Cl-sensitized reactions to the decomposition were estimated at different initial concentrations. The addition of CCl(4) to CHCl(3) or CH(2)Cl(2) increased their decomposition rates via increase of the .Cl concentration, whereas the addition of CH(2)Cl(2) to CHCl(3) decreased its degradation rate, suggesting that CH(2)Cl(2) acts as a .Cl radical scavenger. The variation of the product distribution confirms the effect of the composition of the irradiated gas mixtures on the relative contributions of .Cl-sensitized reactions and direct photolysis.     

An agenda for assessing and improving conservation impacts of sustainability standards in tropical agriculture

Sustainability standards and certification serve to differentiate and provide market recognition to goods produced in accordance with social and environmental good practices, typically including practices to protect biodiversity. Such standards have seen rapid growth, including in tropical agricultural commodities such as cocoa, coffee, palm oil, soybeans, and tea. Given the role of sustainability standards in influencing land use in hotspots of biodiversity, deforestation, and agricultural intensification, much could be gained from efforts to evaluate and increase the conservation payoff of these schemes. To this end, we devised a systematic approach for monitoring and evaluating the conservation impacts of agricultural sustainability standards and for using the resulting evidence to improve the effectiveness of such standards over time. The approach is oriented around a set of hypotheses and corresponding research questions about how sustainability standards are predicted to deliver conservation benefits. These questions are addressed through data from multiple sources, including basic common information from certification audits; field monitoring of environmental outcomes at a sample of certified sites; and rigorous impact assessment research based on experimental or quasi‐experimental methods. Integration of these sources can generate time‐series data that are comparable across sites and regions and provide detailed portraits of the effects of sustainability standards. To implement this approach, we propose new collaborations between the conservation research community and the sustainability standards community to develop common indicators and monitoring protocols, foster data sharing and synthesis, and link research and practice more effectively. As the role of sustainability standards in tropical land‐use governance continues to evolve, robust evidence on the factors contributing to effectiveness can help to ensure that such standards are designed and implemented to maximize benefits for biodiversity conservation.     

Physicochemical characterization of industrial effluents and their effect on fish survival.

Water samples taken from selected industrial drainages and receiving streams in and around Islamabad, Pakistan, during the summers of 1987 to 1990 showed disturbances in pH and low oxygen levels. Selected metals (Fe, Pb, Zn, Cd, Cu, Ni, Hg) were higher in all effluents than in receiving waters. Static bioassays of the undiluted industrial effluents from three sites caused 100% mortality in carp during the first 24 hrs. Fishes also suffered 30 to 60% mortality when exposed to other undiluted industrial effluents and some mortality when industrial effluents were diluted by 50%.     

CALIBRATION AND APPLICATION OF QUAL-II TO THE LOWER WINOOSKI RIVER1

ABSTRACT: A modified version of the U.S. Environmental Protection Agency's QUAL-II water quality simulation model is calibrated and applied to the Lower Winooski River, Vermont. The river flows through the metropolitan Burlington area and is impacted by several industrial and municipal point sources and by operation of hydropower facilities. Several structural modifications are made in the model to improve water quality simulations in rivers impacted by algal growth; these include the addition of organic nitrogen and organic phosphorus compartments and provision for algal uptake of ammonia and/or nitrate nitrogen. The model is interfaced with statistical programs which facilitate tabulation, display, and analysis of observed and predicted concentrations. The model is calibrated and tested against data from two intensive water quality surveys. Applications demonstrate the factors controlling water quality and sensitivities to point source waste management strategies and flow, as influenced by hydropower operations.     

Individual variation in winter foraging of black-capped chickadees

Summary Wintering black-capped chickadees (Paridae: Parus atricapillus) in northwestern Massachusetts showed a high degree of individual variation in foraging behavior. After accounting for the effects of different habitats and weather conditions, individual differences comprised 6–17% of the total observed variation in four measures of foraging location and rate of feeding. Differences between age and sex groups were not significant and explained comparatively little variation (0.0–1.4%). The chickadees did not fall into a few distinct behavioral categories but instead showed continuous variation on all measures of foraging behavior. It appeared that some variation among individuals was a consequence of behavioral convergence within social groups, since birds that were observed together were more similar in their foraging than expected by chance, after taking habitat differences into account. Our results therefore do not support the interpretation that individual variation in feeding behavior serves to reduce exploitation competition within social groups.     

Consumer response to integrated pest management and certification

This study investigated consumer awareness of integrated pest management (IPM) and the effects of two marketing strategies. Specific objectives were to find whether eastern Massachusetts farmstand and farmers' market customers purchasing sweet corn care how their food is grown, whether they are aware of IPM, whether they would prefer to buy IPM-certified sweet corn and why, and whether the marketing methods presently available to IPM-certified growers can enhance awareness of IPM. In 1993, the Massachusetts Department of Food and Agriculture in collaboration with the IPM Program at the University of Massachusetts began a pilot IPM certification program for sweet corn and strawberries, designated ‘Partners with Nature’ (PWN). This study compared a ‘passive’ and ‘active’ PWN marketing strategy with a control that did not have any PWN publicity. The passive strategy was simply display of a PWN certificate and poster. The active strategy also included newspaper advertisements, clear labeling of corn as IPM-certified at the point of selection, a PWN sticker placed on bags of corn at payment, personally thanking customers for ‘buying our IPM-certified sweet corn’, and IPM brochures available to customers. Thirty purchasers of IPM-grown corn were interviewed at each of six farmstands and six farmers' markets.The dominant reason why customers patronize farmstands and farmers' markets was convenience. As found by other northeastern surveys, awareness of IPM was low: only 19% had heard of IPM before the survey, and only 38% of these could mention a specific method used in IPM. Although 45% of the respondents initially said that they did not care how their food is grown, 85% said that they would prefer to buy IPM-certified sweet corn after hearing a short definition. The definition gave only environmental benefits, but 74% of the customers preferring IPM-certified corn said they would buy it because it is safer or healthier. Most of the respondents claimed that they would be willing to pay 10% more for IPM-certified corn. Simply displaying an IPM poster had no significant results on consumer preference for IPM-grown produce, but active marketing significantly raised awareness of IPM and the PWN program.This study demonstrated the willingness of customers to support IPM because they believe it will have positive consequences for human health and environmental quality. It is concluded that sweet corn marketing based on IPM certification positively influenced consumer reactions to IPM; and a more extensive, diverse marketing strategy would enhance consumer awareness and support.     

Preserving Environmental Integrity in standardised baselines: The role of additionality and uncertainty

The European Union EU project PROBASE hasexplored a range of possible multi projectstandardised benchmarks as a way ofencouraging projects under Joint Implementation (JI) and the Clean Development Mechanism (CDM)by minimising transaction costs. The aim ofthis paper is to examine the environmentalintegrity of the use of standardisedbaselines and to explore the role ofadditionality. The environmental integritydepends on the uncertainty in emissionreductions, which was estimated bygenerating scenario baselines and comparingthese with the standardised baselines. Thishas allowed a comparison of selected multiproject baselines with the envelope ofuncertainty on the reductions. The projectsincluded a range of electricity supply,heat sector, cogeneration and methane(CH$_{4}$) projects in different countries. Theanalysis showed that the key uncertaintieswere in the technology fuel selection inthe baseline, the continued additionalityof the project emission reductions,uncertainties in some project emissions(e.g. spinning reserve emissions for wind)and data uncertainties. The effect on theestimation of reductions was in the range±12% to ±46% for the electricityprojects and from ±19% to ±57%for the heat and Combined Heat and Power CHP sector projects.Comparison with the envelope of uncertaintyfor the range of projects showed that multiproject electricity sector baselines whichhave been weighted or use high technologyperformance benchmarks (e.g. Organization for Economic Cooperation and Development OECD)can provide conservative estimates buttheir general nature can lead to variationsbetween countries. We would recommend thatthe country-specific context must be takeninto account so that standardised baselinesfor the electricity sector are generated onthe basis of country specificcharacteristics, the project type, andwhether it provides new or existing demand.The conservative scenario produced shouldthen be weighted. Whereas weightings havebeen applied to account for uncertaintiesor to bias towards renewables, we havesuggested a weighting factor of 25% on theelectricity baseline for large projectsbased on an analysis of the effect ofnon-additionality on emission reductionuncertainty. For heat projects, theappropriate benchmark is a technology/fuelbenchmark which is deemed relevant for theheat sector in that (part of the) country.Again we suggest that a weighted sectorbaseline is required to take account of theuncertainties. These recommendations applyto large projects only for a 10-yearcrediting lifetime.