Distribution of organochlorine compounds in the sea-surface microlayer, water column and sediment of Singapore's coastal environment

Hexachlorocyclohexanes (HCHs), dichlorodiphenylethanes (DDTs) and 38 PCB congeners were determined in the water column (sea-surface microlayer, subsurface, mid-depth and bottom water) and sediments from Singapore's coastal environment. The concentration ranges for summationHCHs, summationDDTs and summationPCBs in the seawater dissolved phase (DP) were 101-6110 (mean 1833), <5-405 (mean 76) and 60-6979 (mean 1611)pg/l, respectively. The concentration ranges for summationHCHs, summationDDTs and summationPCBs in the suspended particulate matter (SPM) were 26-2395 (mean 243), <5-124 (mean 19) and 38-3793 (mean 715) pg/l, respectively. Concentration levels in sediments ranged between 521 and 1758 (mean 1094), 50 and 290 (mean 88) and 339 and 1356 (mean 858) pg/g for summationHCHs, summationDDTs and summationPCBs, respectively. It was shown that the interfaces of the sea-surface microlayer (SML) and near bottom water are important compartments for the distribution of organochlorine compounds (OCs) in the water column. In comparison with data from China, the concentration levels in the water column and sediments of Singapore can be considered as low, but the reported levels were higher compared to available data from Europe.     

Copper availability in seven Israeli soils incubated with and without biosolids

Land application is becoming a preferred option for disposal of sewage sludge (biosolids) from wastewater treatment plants. However, it creates potential risks due to the heavy metal contents of these materials, with copper (Cu) being of chief concern. The long-term fate of biosolid metals applied to agricultural soils is not well understood, particularly in the soils of the Middle East. This investigation was conducted to determine whether the availability of Cu changes with time in biosolid-amended and nonamended soils from Israel. Seven soils, typifying the span of properties and formation environments encountered in Israel, were incubated with and without biosolids for 7 yr, and changes in organic carbon (OC) content and labile Cu concentration were determined. Isotopic exchange techniques, using 64Cu, and ion activity measurements, using a Cu2+ ion selective electrode, revealed that the available Cu concentration remained relatively low and stable over the 7-yr incubation. This was despite substantial reductions in OC. This study shows that, with regard to Cu, application of such biosolids to these soils at rates of up to 250 Mg ha(-1) does not pose a threat to the environment in the short to medium term.     

How has a shortage of census and geological information impeded the regularization of artisanal and small‐scale mining?

There is growing consensus that a combination of laissez‐faire policies, ad hoc regulation and debilitating support services has perpetuated socio‐economic and environmental deterioration in the artisanal and small‐scale mining (ASM) industry. However, a lack of anthropological and geological information on ASM prevents many governments both from improving the policy environment of the industry, and from providing more robust extension services to its operators. This article aims to examine more precisely how a deficiency of baseline census and geological data has inhibited industry formalization and undermined many of the measures implemented to address pressing problems at ASM sites. Specifically, it is argued that insufficient knowledge of artisanal mining populations — including their demographic structure — and of areas suitable for ASM activities affects the ability of a government to regularize, as well as to improve, the organization of this largely informal sector of industry. Case studies of Ghana and Zimbabwe are used to illustrate how the undertaking of low‐budget projects in areas of geological prospecting and population analysis could improve the efficiency of ASM assistance.     

EVALUATION OF CURVE NUMBER PROCEDURES TO PREDICT RUNOFF IN GLEAMS1

ABSTRACT: Proper selection of curve number values will improve the capability of the SCS-Curve Number procedure in predicting runoff. Both CREAMS and GLEAMS models use the Smith and Williams (1980) approach of converting CNII (curve number value for average antecedent moisture conditions) into CNI (curve number value for dry antecedent moisture conditions) in calculating the soil retention parameter (S). CREAMS and GLEAMS have been found to under predict runoff because of the internal conversion of CNII to CNI. This study shows modifications of the GLEAMS model using CMI without converting it to CM and it also shows the seasonal curve number approaches with and without converting CNII to CNI. Results indicate that using CNII without internal conversion to CNI provides better runoff and erosion predictions than the original version of GLEAMS and versions with seasonal curve numbers when tested with four years of field data in the Coastal Plain physiographic region of Maryland.     

THERMAL AND DISSOLVED OXYGEN CHARACTERISTICS OF A SOUTH CAROLINA COOLING RESERVOIR1

ABSTRACT: Temperature and dissolved oxygen concentrations were measured monthly from January 1971 to December 1982 at 1-m depth intervals at 13 stations in Keowee Reservoir in order to characterize spatial and temporal changes associated with operation of the Oconee Nuclear Station. The reservoir water column was i to 4°C warmer in operational than in non-operational years. The thermo-dine was at depths of 5 to 15 m before the operation of Oconee Nuclear Station, but was always below the upper level of the intake (20 m) after the station was in full operation; this suggests that pumping by the Oconee Nuclear Station had depleted all available cool hypolimnetic water to this depth. As a result summer water temperatures at depths greater than 10 m were usually 10°C higher after plant operation began than before. By fall the reservoir was nearly homothemious to a depth of 27 m, where a thermocine developed. Seasonal temperature profiles varied with distance from the plant; a cool water plume was evident in spring and a warm water plume was present in the summer, fall, and winter. A cold water plume also developed in the northern section of the reservoir due to the operation of Jocassee Pumped Storage Station. Increases in the mean water temperature of the reservoir during operational periods were correlated with the generating output of the power plant. The annual heat load to the reservoir increased by one-third after plant operations began. The alteration of the thermal stratification of the receiving water during the summer also caused the dissolved oxygen to mix to greater depths.     

Is love of nature in the US becoming love of electronic media? 16-year downtrend in national park visits explained by watching movies,playing video games,internet use,and oil prices

After 50 years of steady increase, per capita visits to US national parks have declined since 1988. This decline, coincident with the rise in electronic entertainment media, may represent a shift in recreation choices with broader implications for the value placed on biodiversity conservation and environmentally responsible behavior. We compared the decline in per capita visits with a set of indicators representing alternate recreation choices and constraints. The Spearman correlation analyses found this decline in NPV to be significantly negatively correlated with several electronic entertainment indicators: hours of television, (rs=-0.743, P<0.001), video games (rs=-0.773, P<0.001), home movies (rs=-0.788, P<0.001), theatre attendance (rs=-0.587, P<0.025) and internet use (rs=-0.783, P<0.001). There were also significant negative correlations with oil prices (rs=-0.547, P<0.025), foreign travel (rs=-0.452, P<0.05), and Appalachian Trail hikers (rs=-0.785, P<0.001). Income was significantly positively correlated with foreign travel (rs=0.621, P<0.005) but negatively correlated with national park visits (rs=-0.697, P<0.005). There was no significant correlation of mean number of vacation days, indicating available vacation time is probably not a factor. Federal funding actually increased during this period, and so was rejected as a probable factor. Park capacity was rejected as limiting since both total overnight stays and visits at the seven most popular parks rose well into the mid-1990s. Aging of baby boomers was also rejected as they are only now reaching retirement age, and thus during the period of visitation decline were still of prime family vacation age. Multiple linear regression of four of the entertainment media variables as well as oil prices explains 97.5% of this recent decline (r=0.975, multiple r2=0.950, adjusted multiple r2=0.925, SE=0.015, F=37.800, P<0.0001). We may be seeing evidence of a fundamental shift away from people's appreciation of nature (biophilia, Wilson 1984) to 'videophilia,' which we here define as "the new human tendency to focus on sedentary activities involving electronic media." Such a shift would not bode well for the future of biodiversity conservation.     

No net loss of what,for whom?: stakeholder perspectives to Biodiversity Offsetting in England

Market-based instruments (MBIs) have emerged as a popular approach to balance development and conservation objectives. However, their ability to accomplish this is often beset by poor implementation in practice. This is testament to a widening gap between the rate of policy development and implementation of MBIs and the maturity of research and evaluation on their design, and impact on affected stakeholders. Within this context, this paper examines multi-stakeholder perspectives to the adoption of Biodiversity Offsetting in England, an instrument designed to enable biodiversity losses in one place to be compensated through conservation improvements elsewhere. Analysis reveals issues associated with social and ecological compensation of biodiversity loss. Findings suggest that there is a need for a broader consideration of issues surrounding distributive justice, access to nature and the status of ownership over sites of common heritage when accounting for biodiversity loss and its compensation. This message is salient to both the study context as well as the burgeoning international practice of Biodiversity Offsetting.     

Multi-year hourly PM2.5 carbon measurements in New York: Diurnal,day of week and seasonal patterns

Multi-year hourly measurements of PM_2.5 elemental carbon (EC) and organic carbon (OC) from a site in the South Bronx, New York were used to examine diurnal, day of week and seasonal patterns. The hourly carbon measurements also provided temporally resolved information on sporadic EC spikes observed predominantly in winter. Furthermore, hourly EC and OC data were used to provide information on secondary organic aerosol formation. Average monthly EC concentrations ranged from 0.5 to 1.4 μg m^?3 with peak hourly values of several μg m^?3 typically observed from November to March. Mean EC concentrations were lower on weekends (approximately 27% lower on Saturday and 38% lower on Sunday) than on weekdays (Monday to Friday). The weekday/weekend difference was more pronounced during summer months and less noticeable during winter. Throughout the year EC exhibited a similar diurnal pattern to NO_x showing a pronounced peak during the morning commute period (7–10 AM EST). These patterns suggest that EC was impacted by local mobile emissions and in addition by emissions from space heating sources during winter months. Although EC was highly correlated with black carbon (BC) there was a pronounced seasonal BC/EC gradient with summer BC concentrations approximately a factor of 2 higher than EC. Average monthly OC concentrations ranged from 1.0 to 4.1 μg m^?3 with maximum hourly concentrations of 7–11 μg m^?3 predominantly in summer or winter months. OC concentrations generally correlated with PM_2.5 total mass and aerosol sulfate and with NO_x during winter months. OC showed no particular day of week pattern. The OC diurnal pattern was typically different than EC except in winter when OC tracked EC and NO_x indicating local primary emissions contributed significantly to OC during winter at the urban location. On average secondary organic aerosol was estimated to account for 40–50% of OC during winter and up to 63–73% during summer months.