Planning environmental sanitation programmes in emergencies

Environmental sanitation programmes are vital for tackling environmental-related disease and ensuring human dignity in emergency situations. If they are to have maximum impact they must be planned in a rapid but systematic manner. An appropriate planning process comprises five key stages: rapid assessment and priority setting; outline programme design; immediate action; detailed programme design; and implementation. The assessment should be based on carefully selected data, which are analysed via comparison with suitable minimum objectives. How the intervention should be prioritised is determined through objective ranking of different environmental sanitation sector needs. Next, a programme design outline is produced to identify immediate and longer-term intervention activities and to guarantee that apposite resources are made available. Immediate action is taken to meet acute emergency needs while the detailed programme design takes shape. This entails in-depth consultation with the affected community and comprehensive planning of activities and resource requirements. Implementation can then begin, which should involve pertinent management and monitoring strategies.     

Hydropower development in the lower Mekong basin: alternative approaches to deal with uncertainty

Governments in the Lower Mekong Basin (LMB) face decisions that involve trade-offs between the economic benefits from hydropower generation and potentially irreversible negative impacts on the ecosystems that provide livelihoods and food security to the rural poor. As a means of comparing these trade-offs, a sensitivity analysis of the benefit-cost analysis of certain Basin Development Plan (BDP) scenarios was undertaken. By changing some key assumptions in the BDP about discount rates, the value of lost capture fisheries, future aquaculture production in the LMB, and the value of lost ecosystem services from wetlands to reflect the full range of uncertainty, at the extremes, there could be a reversal of the Net Present Value (NPV) estimates of the scenarios from a positive $33 billion to negative $274 billion. This report recommends when dealing with large-scale, complex projects: a more comprehensive, integrated human and natural systems framework and adaptive management approach to LMB planning and development that deals with the entire watershed; a more comprehensive analysis and treatment of risk and uncertainty; a more thorough assessment of the value of direct and indirect ecosystem services; a broader set of scenarios that embody alternative models of development, broader stakeholder participation; and better treatment of the effects of infrastructure construction on local cultures and the poor.     

Social and ecological facets of pest management in Honduran subsistence agriculture: implications for IPM extension and natural resource management

In subsistence farming systems of the developing world, adoption of resource-conserving practices such as integrated pest management (IPM) is often strikingly low. This has partially been ascribed to researchers’ limited understanding of how technologies develop at the interface of the systems’ social and ecological components. In Honduras (Central America), there exists concern about limited adoption and diffusion of IPM technologies in certain smallholder production systems. In this study, we determine social and ecological drivers of IPM adoption in subsistence maize production in the country’s hillside environment. Honduran small-scale maize production is typified by a key insect pest (the fall armyworm, Spodoptera frugiperda) being partly kept at bay through action of a diverse natural enemy complex, including ants, social wasps, carabid beetles, and spiders. Local agricultural landscapes, primarily shaped through shifting cultivation, provide key resources to maintain this natural enemy diversity. These local ecological conditions and related natural enemy abundance strongly influence farmers’ agroecological knowledge and pest management practices. In the meantime, farmer practices are also affected by local communication networks, which help validate and spread IPM concepts and technologies. Based on our findings, we advocate a holistic approach to improve IPM extension through mapping of agroecological opportunities, visualization of regional patterns in farmer knowledge, and associated priority setting. Local IPM capacity could be built through institutional strengthening and adaptive comanagement, while IPM training should be linked with natural resource management initiatives. These approaches may eventually improve the way IPM is delivered to small-scale farmers who operate in the ecologically diverse environments of the tropics.     

Distributions of radionuclide sorption coefficients (Kd) in sub-surface sediments and the implications for transport calculations

The effect of the spatial variability of K_d on calculations of contaminant travel time in the vadose zone was determined. Depth discrete measurements of K_d were made for a suite of radionuclides (¹⁰⁹Cd, ⁵⁷Co, ⁶⁰Co, ⁸⁵Sr, ¹³⁷Cs, and ⁸⁸Y) utilizing a sediment core from the E-Area at the Savannah River Site. The K_d’s were ordered as ⁸⁵Sr²⁺ < ¹³⁷Cs⁺ < ¹⁰⁹Cd²⁺ < ⁵⁷Co²⁺ = ⁶⁰Co²⁺ << ⁸⁸Y³⁺ and the values generally fell below or near the lowest quartile of values reported in the literature. Correlations were generally weak between soil properties and K_d values. Most importantly, all of the K_d distributions could be reasonably approximated as log-normal. Deterministic and stochastic calculations of contaminant travel time to the water table were made. The deterministic calculations were based on each of three conceptual models of the vadose zone: complete stratification (17 strata, each with a different K_d), two strata (two sections of the vadose zone, each characterized by a single, average K_d), and unstratified (a single zone with an average K_d). Stochastic calculations were based on log-normal fits to the K_d data. The two strata model generally yielded travel times 2× greater than those in the completely stratified model. The unstratified model yielded travel times that were between 3 and 5 times greater than the completely stratified model. The stochastic mean travel times were comparable to those of the two strata model.     

Sea-level rise vulnerability in the countries of the Coral Triangle

Sea-level rise is a major threat facing the Coral Triangle countries in the twenty-first century. Assessments of vulnerability and adaptation that consider the interactions among natural and social systems are critical to identifying habitats and communities vulnerable to sea-level rise and for supporting the development of adaptation strategies. This paper presents such an assessment using the DIVA model and identifies vulnerable coastal regions and habitats in Coral Triangle countries at national and sub-national levels (administrative provinces). The following four main sea-level rise impacts are assessed in ecological, social and economic terms over the twenty-first century: (1) coastal wetland change, (2) increased coastal flooding, (3) increased coastal erosion, and (4) saltwater intrusion into estuaries and deltas. The results suggest that sea-level rise will significantly affect coastal regions and habitats in the Coral Triangle countries, but the impacts will differ across the region in terms of people flooded annually, coastal wetland change and loss, and damage and adaptation costs. Indonesia is projected to be most affected by coastal flooding, with nearly 5.9 million people expected to experience flooding annually in 2100 assuming no adaptation. However, if adaptation is considered, this number is significantly reduced. By the end of the century, coastal wetland loss is most significant for Indonesia in terms of total area lost, but the Solomon Islands are projected to experience the greatest relative loss of coastal wetlands. Damage costs associated with sea-level rise are highest in the Philippines (US $6.5 billion/year) and lowest in the Solomon Islands (US $70,000/year). Adaptation is estimated to reduce damage costs significantly, in particular for the Philippines, Indonesia, and Malaysia (between 68 and 99%). These results suggest that the impacts of sea-level rise are likely to be widespread in the region and adaptation measures must be broadly applied.     

Triclosan in waste and surface waters from the upper Detroit River by liquid chromatography-electrospray-tandem quadrupole mass spectrometry

Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is an antimicroibial disinfectant agent used in a wide array of consumer products. An analytical method based on solid-phase extraction (SPE) followed by reverse phase, liquid chromatography coupled with electrospray ionization (negative)-tandem quadrupole mass spectrometry (LC-ESI(-)-MS/MS; in the multiple reaction monitoring (MRM) mode) was developed, optimized and validated for the determination of triclosan in wastewater/sewage treatment plant (WSTP) effluent and surface waters from the upper Detroit River (Canada). The mean recoveries (+/-%RSD) of triclosan and the internal standard 2'-HO-tribromodiphenyl ether (2'-HO-BDE-28) spiked to surface water and WSTP effluent samples ranged similarly from 104+/-8% and 91+/-10%, respectively, and method limits of quantification were in the low ppb/high ppt range. However, ESI(-) enhancement was found for both analytes due to sample matrix effects, as indicated by % process efficiencies (a measure of ESI(-) enhancement/suppression), which were in the 111-128% range. We report the first known assessment of triclosan in the Detroit River watershed of the Great Lakes, which preliminarily examined the presence and UV-treatment effects on triclosan in effluent from the major WSTP serving the City of Windsor, Ontario, Canada, and fate in surface waters of the upper Detroit River. Triclosan in WSTP effluent decreased 22% after final UV treatment to a mean concentration of 63 ng/L. Concentrations were further reduced to 4 and 8 ng/L (a >90% reduction) in surface water samples from sites downstream on the Canadian shoreline of the Detroit River, which was due to dilution. Two hydroxylated tribrominated diphenyl ethers, which are structurally similar to triclosan, were also detected in WSTP effluent and surface water samples.     

Reconstruction of radioactive plume characteristics along Chernobyl's Western Trace

Using data obtained from 435 radiation sampling stations in the Red Forest, 1.5 km W if the Chernobyl Nuclear Complex, we reconstructed the deposition pathway of the first plume released by the accident, Chernobyl's Western Trace. The dimensions and deposition rates of the plume remain sharply defined 15 years after the accident. Assuming a uniform particle distribution within the original cloud, we derived estimates of plume dimensions by applying geometric transformations to the coordinates at each sample point. Our derived estimates for the radioactive cloud accounted for 87% of the variation of radioactivity in this region. Results show a highly integrated bell-shaped cross-section of the cloud of radiation, approximately 660 m wide and 290 m high, traveling at a bearing of 264 degrees from reactor IV. Particle sizes within Chernobyl's Western Trace were within the most dangerous range for inhaled aerosols (2-5 microm). Therefore, reconstruction of the dispersion of such particles is critical for understanding the aftermath of nuclear and biological aerosol releases.     

Using air pollution based community clusters to explore air pollution health effects in children

To study respiratory health effects of long-term exposure to ambient air pollutant mixture, we observed 7058 school children 5-16 years of age living in the four Chinese cities of Lanzhou, Chongqing, Wuhan, and Guangzhou. These children were enrolled from elementary schools located in eight districts, one urban district and one suburban district in each of the above cities. Ambient levels of PM(2.5), PM(10-2.5), total suspended particles (TSP), SO(2), and NO(x) were measured in these districts from 1993 to 1996. Based on a cluster analysis of arithmetic mean concentrations of PM(2.5), PM(10-2.5), (TSP-PM(10)), SO(2), and NO(x), we classified these children into four ordinal categories of exposure to ambient air pollutant mixtures. We tested for exposure-response relationships using logistic regression models, controlling for relevant covariates. We observed monotonic, positive relationships of exposure to the pollutant mixture with prevalence rates of cough with phlegm and wheeze. Other outcomes were not associated with the exposure in a monotonic exposure-response pattern. Even so, odds ratios for cough, phlegm, bronchitis, and asthma in the higher exposure district clusters were all higher than in the lowest exposure district cluster. We found evidence that exposure to the pollutant mixtures had adverse effects on children living in the four Chinese cities.     

Sink populations in carnivore management: cougar demography and immigration in a hunted population.

Carnivores are widely hunted for both sport and population control, especially where they conflict with human interests. It is widely believed that sport hunting is effective in reducing carnivore populations and related human-carnivore conflicts, while maintaining viable populations. However, the way in which carnivore populations respond to harvest can vary greatly depending on their social structure, reproductive strategies, and dispersal patterns. For example, hunted cougar (Puma concolor) populations have shown a great degree of resiliency. Although hunting cougars on a broad geographic scale (> 2000 km2) has reduced densities, hunting of smaller areas (i.e., game management units, < 1000 km2), could conceivably fail because of increased immigration from adjacent source areas. We monitored a heavily hunted population from 2001 to 2006 to test for the effects of hunting at a small scale (< 1000 km2) and to gauge whether population control was achieved (lambda < or = 1.0) or if hunting losses were negated by increased immigration allowing the population to remain stable or increase (lambda > or = 1.0). The observed growth rate of 1.00 was significantly higher than our predicted survival/fecundity growth rates (using a Leslie matrix) of 0.89 (deterministic) and 0.84 (stochastic), with the difference representing an 11-16% annual immigration rate. We observed no decline in density of the total population or the adult population, but a significant decrease in the average age of independent males. We found that the male component of the population was increasing (observed male population growth rate, lambda(OM) = 1.09), masking a decrease in the female component (lambda(OF) = 0.91). Our data support the compensatory immigration sink hypothesis; cougar removal in small game management areas (< 1000 km2) increased immigration and recruitment of younger animals from adjacent areas, resulting in little or no reduction in local cougar densities and a shift in population structure toward younger animals. Hunting in high-quality habitats may create an attractive sink, leading to misinterpretation of population trends and masking population declines in the sink and surrounding source areas.     

Use of watershed characteristics to select control streams for estimating effects of metal mining wastes on extensively disturbed streams

Impacts of sediments and heavy metals on the biota of streams in the copper-mining district of southwestern Montana were examined by comparing aquatic communities of impacted streams with those of control streams. Control streams were chosen through the use of a technique that identifies similar streams based on similarities in their watershed characteristics. Significant differences between impacted and control sites existed for surface substrate, riparian vegetation, and the number of macroinvertebrate taxa. These results revealed that: (a) chemical and physical habitats at the impacted sites were disrupted, (b) the presence of trout was an inadequate measure of ecological integrity for these sites, and (c) watershed classification based on a combination of mapped terrestrial characteristics provided a reasonable method to select control sites where potential control sites upstream and downstream were unsuitable.