Community attitudes toward forest conservation programs through collaborative protected area management in Bangladesh

The formulation of conservation policies with options for creating protected areas is significantly influenced by the social factors of the surrounding communities. Therefore, indigenous knowledge, attitudes and perceptions of the local communities need to be explored during the planning and implementation stages of conservation projects. A government-initiated experiment in co-management was conducted in the Rema-Kalenga Wildlife Sanctuary, Bangladesh. This paper analyzes the attitudes toward conservation by members of local communities living in and around the wildlife sanctuary. Training incentives on alternative income-generating (AIG) activities and allotment of agricultural lands were distributed among the Forest User Groups. It is of interest to policy makers and resource managers whether this technique leads to improved attitudes on the part of local people. Although there were different attitudes toward protected areas and conservation, overall, a favorable attitude of the respondents was observed. The opinions of respondents also varied based on factors such as village position, village dependency level on forest resources, ethnicity and gender. Increase in annual income resulting from the augmented skills by trainings on AIG activities and getting agricultural lands leased from the Forest Department contributed significantly to the variation in respondents’ conservation attitudes. It is suggested that eliminating inequity and inequality in incentive distribution, discovering and launching training on more need-based livelihood activities, and liberalizing the restriction of resource extraction from the protected area by fixing the harvesting limit would encourage the community to be more cordially and actively involved in the conservation efforts of the sanctuary.     

Methodology for identifying particle sources in indoor environments

Growing concern about airborne particles in indoor environments requires fast source identification in order to apply remedial actions. A methodology for identifying sources emitting particles larger than 0.5 microm was designed and applied. It includes: (1) visual inspection of interior surfaces in order to identify deposited particles and inspection of potential sources (equipment, materials, activities etc.) of airborne particles. (2) Technical measurements of airborne particles at different positions in a building with simultaneous logging of activities. (3) Isolating potential activities/particle sources in a test chamber, initially free from particles, for controlled characterizations of the particles generated. The methodology was applied in a study of three houses in southern Sweden. The results show that source identification is facilitated by knowledge of concentration variations between different rooms, real-time measurements together with activity reports and information on particle characteristics that are comparable with results from laboratory simulations. In the houses to which the methodology was applied, major particle emissions from textile handling were identified, which were likely due to detergent zeolite residues.     

THRESHOLD TIME SERIES MODELING OF TWO ICELANDIC RIVERFLOW SYSTEMS1

ABSTRACT: This paper reports our experience in building time series models which connect the flows in two Icelandic rivers with the meteorological variables of precipitation and temperature. Two rivers with different hydrological characteristics were studied. In areas where precipitation may be either in the form of rain or snow linear models are inadequate to describe the relationship between the river and the meteorological variables. The methodology of threshold models recently developed seems to be well suited for taking into account the sharp difference in the relationship according to whether it is freezing or not. The possibility of identifying an alternative threshold variable is also explored.     

Aspiration and sampling efficiencies of the TSP and louvered particulate matter inlets

An experimental system was developed for the rapid measurement of the aspiration/transfer efficiency of aerosol samplers in a wind tunnel. We attempted to measure the aspiration and particle transfer characteristics of two inlets commonly used for sampling airborne Particulate Matter (PM): the 'Total Suspended Particulate' or TSP inlet, and the louvered 'dichotomous sampler inlet' typically used in sampling PM10 or PM2.5. We were able to determine the fraction of the external aerosol that enters the inlet and is transferred through it, and hence is available for collection by a filter, or further size fractionation into PM10 or PM2.5. This 'sampling efficiency' was analysed as a function of dimensionless aerodynamic parameters in order to understand the factors governing inlet performance. We found that for the louvered inlet the sampling efficiency increases as the external wind increases. Under all conditions expected in practical use the louvered inlet aspirates sufficient PM to allow either PM10 or PM2.5 to be selected downstream. The TSP inlet's sampling efficiency decreases with increasing external wind, and the TSP inlet is likely to under-sample the coarse end of the PM10 fraction at moderate and high external winds. As this inlet is generally not used with a downstream size fractionator, changes in sampling efficiency directly affect the measured aerosol concentration. We also investigated whether it is possible to dimensionally scale the PM inlets to operate at either higher or lower flow rates, while preserving the same sampling characteristics as the current full-scale, 16.67 L min(-1) versions. In the case of the louvered inlet, our results indicate that scaling to lower flow rates is possible; scaling to higher flow rates was not tested. For the TSP sampler, the sampling efficiency changes if the sampler is scaled to operate at smaller or larger flow rates, leading to unreliable performance.     

Factors influencing PM10 emissions from road pavement wear

Accelerated pavement wear is one of the major environmental disadvantages of studded tyres in northern regions and results in increased levels of PM₁₀. Measurements of PM₁₀ in a road simulator hall have been used to study the influence of pavement properties, tyre type and vehicle speed on pavement wear. The test set-up included three different pavements (one granite and two quartzite with different aggregate sizes), three different tyre types (studded, non-studded, and summer tyres) and different speeds (30–70 km h^?1). The results show that the granite pavement was more prone to PM₁₀ production compared to the quartzite pavements. Studded winter tyres yield tens of times higher PM₁₀ concentrations compared to non-studded winter tyres. Wear from summer tyres was negligible in comparison. It was also shown that wear is strongly dependent on speed; every 10 km h^?1 increase yielded an increase of the PM₁₀ concentration of 680 μg m^?3 in one of the simulator experiments.     

A chemosorptive cylindrical denuder designed for personal exposure measurements of isocyanates-evaluation on generated aerosols of 4,4'-methylenediphenyl diisocyanate

A denuder/filter system constructed for solvent-free personal exposure measurements was evaluated for separation of vapour and particulate 4,4'-methylenediphenyl diisocyanate (4,4'-MDI) generated from heated PUR-foam. The two different phases were collected in the denuder and on the filter, respectively, by chemosorption on a polydimethylsiloxane (SE-30)-dibutylamine (DBA) stationary phase. Both repeatability and the total mass concentration of 4,4'-MDI were similar to that obtained from the reference method, in this case an impinger/filter system. The penetration of particles through the denuder at 300 ml min(-1) was nearly 100% in the particle size range 25 to 700 nm, which fits well with the Gormley-Kennedy equation. Denuder/filter sampling of the 4,4'-MDI aerosol at 500 ml min(-1) yielded a phase distribution that was in accordance with the results from the reference method. The method limit of detection was 6 ng m(-3) and 4 ng m(-3) for the denuder and filter, respectively, when using an air sampling flow rate of 300 ml min(-1) and a sampling period of 15 min. This is well below the Swedish occupational exposure limit (OEL) of 50 and 100 microg m(-3) for an 8-hour working day and a 5-min period, respectively.