Contrasts in Livelihoods and Protein Intake between Commercial and Subsistence Bushmeat Hunters in Two Villages on Bioko Island,Equatorial Guinea

Across West and Central Africa, wildlife provides a source of food and income. We investigated the relation between bushmeat hunting and household wealth and protein consumption in 2 rural communities in Bioko Island, Equatorial Guinea. One village was dedicated to commercial hunting, the other trapped game primarily for food. We tested whether commercial‐hunter households were nutritionally advantaged over subsistence‐hunter households due to their higher income from the bushmeat trade and greater access to wild‐animal protein. We conducted bushmeat‐offtake surveys in both villages (captures by hunters and carcasses arriving to each village). Mammals (including threatened primates: black colobus [Colobus satanas], Preussi's guenon [Allochrocebus preussi], and russet‐eared guenon [Cercopithecus erythrotis]), birds, and reptiles were hunted. The blue duiker (Philantomba monticola), giant pouched rat (Cricetomys emini), and brush‐tailed porcupine (Atherurus africanus) contributed almost all the animal biomass hunted, consumed, or sold in both villages. Monkeys and Ogilbyi's duikers (Cephalophus ogilbyi) were hunted only by commercial hunters. Commercial hunters generated a mean of US$2000/year from bushmeat sales. Households with commercial hunters were on average wealthier, generated more income, spent more money on nonessential goods, and bought more products they did not grow. By contrast, households with subsistence hunters spent less on market items, spent more on essential products, and grew more of their own food. Despite these differences, average consumption of vegetable protein and domestic meat and bushmeat protein did not differ between villages. Our results highlight the importance of understanding the socioeconomic and nutritional context of commercial and subsistence bushmeat hunting to correctly interpret ways of reducing their effects on threatened species and to enable the sustainable offtake of more productive taxa. Contrastes en el Sustento y la Ingesta de Proteínas entre Carne de Caza de Subsistencia y Comercial en Dos Aldeas en Isla Bioko, Guinea Ecuatorial     

Multilevel modeling in traffic safety research: two empirical examples illustrating the consequences of ignoring hierarchies

OBJECTIVES: This commentary illustrates the advantages of multilevel modeling compared to statistical techniques that ignore hierarchies, based on two empirical traffic safety examples. METHODS: The common concept shared by different definitions of multilevel modeling is identified and illustrated. Each definition defines multilevel modeling in its own way but they all refer to hierarchies. Conceptual issues inherently related to hierarchies are then pointed out and illustrated. RESULTS: Broadly speaking there are two important consequences of ignoring a hierarchical structure in the data. The first consequence, underestimation of standard errors, is illustrated with data from an observational study on seatbelt behavior. Two effects that were significant at the 5% level in a single-level model were no longer found to be significant in a two-level model. The single-level model is therefore bound to lead to erroneous conclusions regarding variables that could have an impact on seatbelt use and, ultimately, on increasing the level of traffic safety. The second consequence, related to contextual information, is illustrated with data from a roadside survey on drink driving. Of particular interest is the relationship between Traffic Count, an aggregated level 2 explanatory variable and Odds of drink driving, an individual level 1 dependent variable. CONCLUSIONS: Like every statistical technique, multilevel models should be used with caution and reservation. However, given certain limitations, multilevel modeling is very useful and valuable to traffic safety research.     

Comparison of current Federal Reference Methods for ambient lead measurements adjacent to a secondary lead smelter

The United States Environmental Protection Agency (EPA) reduced their National Ambient Air Quality Standard (NAAQS) for lead (Pb) an order of magnitude to a concentration level of 0.15 micrograms per cubic meter (µg/m³) when the new rule was promulgated in 2008. At that time, the possibility of revising the Pb sampling method from total suspended particulate (TSP) to particulate matter less than or equal to 10 µm in diameter (PM₁₀) was considered due to potential measurement bias of the Pb-TSP monitoring technique. The New York State Department of Environmental Conservation (NYSDEC) has been operating source-orientated colocated TSP and PM₁₀ monitors documenting ambient air lead (Pb) concentrations since 2011 at a site adjacent to a secondary Pb smelter in Wallkill, New York. The colocated Wallkill data show a very strong correlation between the readings recorded by these two sampling techniques. After the range of the variability in the individual Pb-PM₁₀/Pb-TSP ratios was reduced by using a 0.005 µg/m³ concentration cut point, because of the concerns about the measurements at low concentrations, an adjustment factor (AF) of 1.49 was calculated using the remaining data set. This AF can be used to estimate Pb-TSP concentrations from Pb-PM₁₀ readings at this Wallkill source-orientated location. It was stated by the EPA that there is only a limited data set in situations where Pb-TSP and Pb-PM₁₀ are colocated, especially for those sites considered to be source-oriented, so the analyses performed and summarized herein for the Wallkill colocated airborne Pb concentration data add to that limited data set.

Implications: These data analyses add to the limited data set in situations where Pb-TSP and Pb-PM₁₀ are colocated to help refine the derivation of a site-specific adjustment factor for estimating TSP Pb concentrations from measured PM₁₀ Pb concentrations. This could assist the EPA in transitioning away from the use of the Pb-TSP monitoring technique, with its indicated measurement bias, for the Pb NAAQS to the use of Pb-PM₁₀ instead. An adjustment factor of 1.49 was calculated that could be used to estimate Pb-TSP concentrations from Pb-PM₁₀ values collected around this source-orientated location.     

REGULATORY WATER QUALITY MONITORING: A SYSTEMS PERSPECTIVE1

ABSTRACT: Regulatory water quality monitoring has evolved to the point where it is a rather complex system encompassing many monitoring purposes and involving many monitoring activities. Lack of a system's perspective of regulatory monitoring hinders the development of effective and efficient monitoring programs to support water quality management. In this paper the regulatory water quality monitoring system is examined in a total systems context. The purposes of regulatory monitoring are reviewed and categorized according to their legal evolution. The activities of regulatory monitoring are categorized and organized into a system which follows the flow of information through the monitoring program. The monitoring purposes and activities are combined to form a monitoring system matrix - a framework within which the total regulatory water quality monitoring system is defined. The matrix, by defining the regulatory monitoring system and clarifying many interactions within the system, provides a basis upon which a more thorough approach to managing, evaluating, and eventually optimizing regulatory monitoring can be developed.     

DEVELOPMENT OF A BACTERIAL TRANSPORT MODEL FOR COARSE SOILS1

ABSTRACT: A bacterial transport model, developed to analyze bacterial translocation in coarse-grained soils, is presented. The complex governing equation is presented first, followed by analyses of each of the major processes influencing bacterial transport. These analyses suggest simplification of the governing equation is feasible when input data on specific processes are limited or unavailable. Model parameters, including bacterial die-off, bacterial distribution, input bacterial concentration, and saturated hydraulic conductivity, were randomly generated using a procedure known to produce either a normal or log-normal distribution of random numbers. Monte Carlo simulations were completed, and the resulting output was used to generate cumulative frequency distributions showing the probability of bacterial transport beyond various soil depths. Results from these simulations indicate that bacteria have a high probability of traveling through coarse-grained soils when low clay content and soil water temperatures limit bacterial retention and die-off.     

Using social network analysis to examine planner involvement in environmentally oriented planning processes led by non-planning professions

Broad stakeholder involvement cannot be assumed in all environmental planning and management processes that have critical land use dimensions. This paper illustrates how concepts and techniques from social network analysis (SNA) can be used to examine and better understand the roles of one type of stakeholders, planners, in environmentally oriented planning and management processes led by other professions. Two cases of natural hazard mitigation planning led by emergency managers illustrate the usefulness of three SNA concepts of network structural characteristics in understanding how differences in planner involvement may influence incorporation of land use approaches in local natural hazard mitigation plans aimed at reducing long term risks from natural hazards.     

Chemical (polycyclic aromatic hydrocarbon and heavy metal) levels in contaminated stormwater and sediments from a motorway dry detention pond drainage system

Chemical (polycyclic aromatic hydrocarbon - PAH and heavy metal) levels in stormwater and sediment samples collected from the London Orbital (M25) motorway drainage dry detention pond at Oxted, Surrey, UK were determined. Such chemicals are derived from vehicular combustion products and the wear and tear materials deposited onto the motorway surface. Gas chromatography-mass spectrometry (GC-MS) was used for the qualitative and quantitative determination of 16 USEPA priority PAHs in motorway drainage sediments. The GC-MS method, incorporating a solid phase extraction step, provides detection limits ranging from 0.17 to 0.41 mg kg(-1)(dry weight). Almost all of the 16 USEPA listed PAHs were detected. Phenanthrene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene and benzo(g,h,i)perylene (PAH numbers 5, 7, 8, 9, 10, 11, 13 and 16) were among the PAHs found at "higher" levels (ranging from 0.3-10.2 mg kg(-1), dry weight) in the sediment samples. PAH levels show little change along the motorway drainage silt trap (facility for reducing the levels of suspended particulate matter in the stormwater). PAH concentrations are considerably higher in the dry detention pond outflow interceptor. Statistical analysis showed that significant correlation coefficients (based on a t-test at the 95% confidence interval) were obtained between those PAHs found at high concentrations over all of the sampling sites. Several PAHs were dispersed beyond the treatment facility and accumulation in the sediment of the deer park resulted in levels ranging from 0.3-1.6 mg kg(-1), dry weight. These PAHs found beyond the treatment facility (in the local farm deer park) may contribute a serious health threat to farm animals or even fish in the aquatic environment. Heavy metal levels (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, Sb and Pb) of the drainage stormwater and sediments were determined by inductively coupled plasma mass spectrometry (ICP-MS), with quality control evaluation using two certified reference materials. Typical detection limits were found to be below 0.1 [micro sign]g l(-1) for stormwater and 0.005 mg kg(-1) for acid digested sediments. Raised heavy metal levels were found throughout the dry detention pond facility and only decrease when the stormwater is diluted following discharge into the river Eden. Statistical analysis also confirms that some significant correlations exist between various heavy metals and PAHs. However, no overall conclusive trend is found indicating that a particular PAH is deposited in sediment relative to a specific heavy metal/s. These results raise some serious concerns about the dispersion and accumulation of chemicals in the sediments of motorway stormwater drainage systems and the need for maintenance and clean-up of contaminated material from such systems.     

Pulsed redistribution of a contaminant following forest fire: cesium-137 in runoff

Of the natural processes that concentrate dispersed environmental contaminants, landscape fire stands out as having potential to rapidly concentrate contaminants and accelerate their redistribution. This study used rainfall simulation methods to quantify changes in concentration of a widely dispersed environmental contaminant (global fallout 137Cs) in soils and surface water runoff following a major forest fire at Los Alamos, New Mexico, USA. The 137Cs concentrations at the ground surface increased up to 40 times higher in ash deposits and three times higher for the topmost 50 mm of soil compared with pre-fire soils. Average redistribution rates were about one order of magnitude greater for burned plots, 5.96 KBq ha(-1) mm(-1) rainfall, compared with unburned plots, 0.55 KBq ha(-1) mm(-1) rainfall. The greatest surface water transport of 137Cs, 11.6 KBq ha(-1) mm(-1), occurred at the plot with the greatest amount of ground cover removal (80% bare soil) following fire. Concentration increases of 137Cs occurred during surface water erosion, resulting in enrichment of 137Cs levels in sediments by factors of 1.4 to 2.9 compared with parent soils. The elevated concentrations in runoff declined rapidly with time and cumulative precipitation occurrence and approached pre-fire levels after approximately 240 mm of rainfall. Our results provide evidence of order-of-magnitude concentration increases of a fallout radionuclide as a result of forest fire and rapid transport of radionuclides following fire that may have important implications for a wide range of geophysical, ecosystem, fire management, and risk-based issues.     

Assessment of Nonpoint Source Pollution from Inactive Mines Using a Watershed-Based Approach

/ A watershed-based approach for screening-level assessment of nonpoint source pollution from inactive and abandoned metal mines was developed and illustrated. The methodology was designed to use limited stream discharge and chemical data from synoptic surveys to derive key information required for targeting impaired waterbodies and critical source areas for detailed investigation and remediation. The approach was formulated based on the required attributes of an assessment methodology, information goals for targeting, attributes of data that are typical of basins with inactive mines, and data analysis methods that were useful for the case study. The methodology is presented as steps in a framework including evaluation of existing data/information and identification of data gaps; definition of assessment information goals for targeting and monitoring design; data collection, management, and analysis; and information reporting and use for targeting. Information generated includes the type and extent of and critical conditions for water-quality impairment, concentrations in and loadings to streams, differences between concentrations in and loadings to streams, and risks of exceeding target concentrations and loadings. Data from the Cement Creek Basin, located in the San Juan Mountains of southwestern Colorado, USA, were used to help develop and illustrate application of the methodology. The required information was derived for Cement Creek and used for preliminary targeting of locations for detailed investigation and remediation. Application of the approach to Cement Creek was successful in terms of cost-effective generation of information and use for targeting.KEY WORDS: Water quality assessment; Nonpoint source pollution; Inactive mines; Watershed