Guatemala strives for environmental and economic sustainability in the Rio Dulce region

Conditions in Guatemala's Rio Dulce National Park (RDNP) present an immediate decision-making challenge concerning the reversal of current destructive environmental trends, and in establishing policies for restoration, protection, and sustainable use. This article summarises results of environmental assessment activities undertaken at three levels: an environmental impact assessment (EIA) of a proposed industrial forestry activity, an environmental assessment of management options for the Rio Dulce National Park, and water management planning for the Rio Dulce/Lago Izabal watershed. A key result of the EIA was to prohibit construction of a barge terminal within the boundaries of the park because it could set a precedent for future development. Management options for the park focused on establishing land-use controls, dealing with river transport more effectively, and identifying funding mechanisms to implement solutions. At the watershed scale, a strategic approach was recommended to identify priority issues for initiating change toward sustainability in the region.     

The use of isomer specific data to characterize and differentiate sources of dioxins into the environment

In a recent comprehensive study of dioxin levels in the environment with several potential historical manufacturing and combustion sources, a simple but effective pattern recognition technique was developed and successfully used to guide the study. Using isomer specific data on 20 tetra isomer groups, the resulting isomer profiles were able to identify dominant sources of dioxin in various areas. Several specific studies and multi-variant statistical procedures were used to confirm the findings.     

Sustaining Jamaica's forests: The protected areas resource conservation project

This study examines Jamaica's attempt to protect a tropical forest reserve. The biophysical setting, and the types and magnitude of forest development pressures are reviewed. Next, Jamaica's approach to developing new land-use strategies and compatible environmental protection and economic development programs are examined. Finally, the practical and theoretical implications by which institutions can be designed to encourage planning for sustainable development are reviewed. The implications suggest how to provide an appropriate mix of cooperation and market competition, by which people acting in their own interests accomplish socially equitable economic development, while protecting the environment for the benefit of future generations. The experience illustrates that effective long-term protection of natural areas requires the building of local relationships and support, the development of local economic activities supportive of conservation, the defining of clear boundaries, and significant monitoring and enforcement. Long-term protection of the Blue and John Crow mountains, and other important natural areas of Jamaica, will also require the development of a workable and enforceable system of land-use planning for the island, and adjustments to the economic incentive structure so that sustainable, nonextractive uses of natural capital are placed on equal footing with other economic uses (e.g., coffee production).     

Hydrologic evaluation of landfill performance (HELP) modeling in bioreactor landfill design and permitting

The practice of operating municipal solid waste landfills as bioreactor landfills has become more common over the past decade. Because simulating moisture balance and flow is more critical in such landfills than in dry landfills, researchers have developed methods to address this problem using the hydrologic evaluation of landfill performance (HELP) model. This paper discusses three methods of applying the HELP model to simulate the percolation of liquids added to landfill waste: the leachate recirculation feature (LRF), the subsurface inflow (SSI) feature, and additional rainfall to mimic liquids addition. The LRF is simple to use but may not be able to bring the landfill to bioreactor conditions. The SSI feature provides a convenient user interface for modeling liquids addition to each layer. The additional rainfall feature provides flexibility to the model, allowing users to estimate the leachate generation rate and the leachate head on bottom liner associated with daily variation in the liquids addition rate. Additionally, this paper discusses several issues that may affect the HELP model, such as the time of model simulation, layers of liquids addition, and the limitations of the HELP model itself. Based on the simulation results, it is suggested that the HELP model should be run over an extended period of time after the cessation of liquids addition in order to capture the peak leachate generation rate and the head on the liner (HOL). From the perspectives of leachate generation and the HOL, there are few differences between single-layer injection and multiple-layer injection. This paper also discusses the limitations of using the HELP model for designing and permitting bioreactor landfills.     

Use of open-path FTIR spectroscopy to address air monitoring needs during site remediations

Although open-path Fourier-transform infrared (FTIR) spectroscopy has been an Environmental Protection Agency (EPA) Toxic Organic Compendium Method since 1996, it has been underutilized as a means to assess exposure to gaseous contaminants during the remediation of hazardous waste sites. This might be considered surprising in light of the many benefits that proper application of this technology can offer. In this article, we provide an overview of the technology and the principle of operation, describe the nature of the data generated, discuss the benefits associated with the technology's use in site clean-up, present emission-rate estimation techniques, and examine the reasons why it has not gained more support over the years. Finally, we present a case study in which the technology was used to drive an 11-month emergency removal action under the direction of the U.S. Environmental Protection Agency.     

Variability in the spatial association patterns of sponge assemblages in response to environmental heterogeneity

Previous work on tropical sponge assemblages has provided strong evidence that sponges coexist on coral reefs through a diversity of positive and negative associations; however, the majority of this work has focused on Caribbean coral reefs. Here, we investigate the intra-phyletic spatial associations between the 20 most abundant sponge species at two sites experiencing different environmental regimes in the Wakatobi National Marine Park, Indonesia. We used a Monte Carlo simulation approach to compare the number of spatial associations between each species pair to that expected if species distribution patterns were non-associative (i.e. random). We found that sponges were predominately randomly distributed at the high coral cover site, whereas most sponges were negatively associated with other sponges at the sedimented, low coral cover site. We also found differences between distribution patterns for specific species at the two sites; a number of species that showed a random distribution pattern at the high coral cover site had negative association patterns at the low coral cover site. Our research supports recent ecological studies suggesting that interactions between species are unlikely to be homogenously distributed, as we found that some sponge species interactions differed depending on the environmental regimes in which they were found; this suggests that species interactions may be spatially variable. Finally, our results contrast with studies from elsewhere, as the sponge assemblages at these two sites in the Wakatobi appear to be dominated by negative associations and random distribution patterns rather than widespread competition.     

Regional Monitoring of Ambient Air Carbon Monoxide in Fairbanks,Alaska

A method employing the timed fill of Mylar bags was used to obtain average carbon monoxide concentration values for ten locations in the Fairbanks, Alaska, area. The method is shown to be accurate, reliable, and inexpensive. The correlation coefficient between the bag sampling method and a continuous carbon monoxide analyzer was 0.945; correlation of carbon monoxide data from several locations to a reference in downtown Fairbanks showed a general decrease with distance from the reference analyzer. Analysis of data from Fairbanks shows that carbon monoxide concentrations during the winter months may have to be reduced 50-75% to achieve the State and National Ambient Air Quality Standards; the high levels of carbon monoxide are the result of emissions from automobile traffic during periods of severe inversion in the Fairbanks basin.