Effect of diet on growth rate and reproductive fitness of Turbo sarmaticus (Mollusca: Vetigastropoda: Turbinidae)

Experiments were conducted to determine the effect of four algal diets (Corallina spp., Gelidium pristoides, Ulva rigida and an equal volume mixture of these seaweeds) on growth and reproduction of the South African gastropod Turbo sarmaticus Linnaeus, 1758. The best growth rate of juveniles (up to 13.8 mm shell length and 34.26 g wet body weight increase in 12 months), reproductive fitness of mature specimens (gonad index up to 33%) and energy reserves (up to 4.76 mg glycogen/100 mg foot tissue) were achieved when T. sarmaticus was fed U. rigida or a mixed diet. In addition, the gonad index of individuals fed these diets was almost twice that of similar-sized field specimens. Juveniles fed Corallina spp. only, grew very little (only 2.4 mm shell length and 4.23 g wet body weight increase in 12 months). The reproductive fitness of adults fed on such a diet was also poor (gonad index <4.5%) and energy reserves were low (<3.5 mg glycogen/100 mg foot tissue). Along the southeastern coast of South Africa, T. sarmaticus has a distinct reproductive cycle with gametogenesis occurring from March/April until August/September, whilst maturity (gonad index = 15%) was maintained until December, after which spawning occurred until March. Received: 6 July 1998 / Accepted: 8 March 1999     

Human maternal and umbilical cord blood concentrations of polybrominated diphenyl ethers

Polybrominated diphenyl ethers (PBDEs), widely used as flame retardants in commercial products, have become ubiquitous environmental contaminants. Although adult human exposure to PBDEs is well documented, developmental exposure is less well characterized. The objectives of this study were to measure maternal and fetal exposure to nine PBDE congeners and to investigate potential associations with birth weight. PBDE congeners were quantified in maternal serum at 24-28 weeks of pregnancy, delivery, and umbilical cord serum (UCS) by gas chromatography-mass spectrometry (GC/MS/MS). Complete blood sample sets were obtained from 97 pregnant women (mean age 33.1 ± 0.5 years). PBDE-28, -47 and -99 were quantified in all samples tested and PBDE-47 was the most abundant congener measured in both maternal (mid-pregnancy and delivery samples geometric mean = 26.9 and 26.9, respectively) and UCS (GM = 56.0 ng g⁻¹ lipid). The UCS concentration for all congeners with the exception of PBDE-153 was higher vs. maternal delivery samples (p < 0.001). Only the UCS concentration of PBDE-17 and -99 were significantly associated (β = −49.860, p = 0.032, and β = −3.645, p = 0.05) with birth weight. However, after adjustment for potential confounders only the association between PBDE-99 and birth weight remained significant (β = −3.951 and p = 0.016). We conclude that: the fetus is exposed to PBDEs from at least the second trimester of pregnancy onward; PBDE congeners are higher in UCS compared to maternal serum samples collected at delivery; and that developmental PBDE exposure is potentially associated with lower birth weight.     

Health Effects of Air Quality Regulations in Delhi, India

This, the first systematic study, quantifies the health effects of air quality regulations in Delhi, which adopted radical measures to improve air quality, including, for example, the conversion of all commercial vehicles to compressed natural gas (CNG), and the closure of polluting industries in residential areas from 2000 to 2002. Air pollution data, collected at 113 sites (spread across Delhi and its neighboring areas) from July-December 2003, were used to compute exposure at the place of residence of 3,989 subjects. A socio-economic and respiratory health survey was administered in 1,576 households. This survey collected time-use, residence histories, demographic information, and direct measurements of lung function with subjects. The optimal interpolation methods were used to link air pollution and respiratory health data at the place of their residence. Resident histories, in combination with secondary data, were used to impute cumulative exposure prior to the air-quality interventions, and the effects of recent air quality measures on lung function were then evaluated. Three important findings emerge from the analysis. First, the interventions were associated with a significant improvement in respiratory health. Second, the effect of these interventions varied significantly by gender and income. Third, consistent with a causal interpretation of these results, effects were the strongest among those individuals who spend a disproportionate share of their time out-of-doors.     

Environmental issues and management strategies for waste electronic and electrical equipment

Issues surrounding the impact and management of discarded or waste electronic and electrical equipment (WEEE) have received increasing attention in recent years. This attention stems from the growing quantity and diversity of electronic and electrical equipment (EEE) used by modern society, the increasingly rapid turnover of EEE with the accompanying burden on the waste stream, and the occurrence of toxic chemicals in many EEE components that can pose a risk to human and environmental health if improperly managed. In addition, public awareness of the WEEE or "e-waste" dilemma has grown in light of popular press features on events such as the transition to digital television and the exportation of WEEE from the United States and other developed countries to Africa, China, and India, where WEEE has often not been managed in a safe manner (e.g., processed with proper safety precautions, disposed of in a sanitary landfill, combusted with proper air quality procedures). This paper critically reviews current published information on the subject of WEEE. The definition, magnitude, and characteristics of this waste stream are summarized, including a detailed review of the chemicals of concern associated with different components and how this has changed and continues to evolve over time. Current and evolving management practices are described (e.g., reuse, recycling, incineration, landfilling). This review discusses the role of regulation and policies developed by governments, institutions, and product manufacturers and how these initiatives are shaping current and future management practices.     

Soil erosion and risk-assessment for on- and off-farm impacts: A test case using the Midhurst area,West Sussex,UK

Soil erosion on agricultural land is a growing problem in Western Europe and constitutes a threat to soil quality and to the ability of soils to provide environmental services. The off-site impacts of runoff and eroded soil, principally eutrophication of water bodies, sedimentation of gravel-bedded rivers, loss of reservoir capacity, muddy flooding of roads and communities, are increasingly recognised and costed. The shift of funding in the European Union (EU) from production-related to avoidance of pollution and landscape protection, raises issues of cross-compliance: public support for agriculture has to be seen to give value-for-money. In this context risk-assessment procedures have been introduced to help farmers recognise sites where either certain crops should not be grown or anti-erosion measures are required. In England, Defra [Defra, 2005a. Controlling Soil Erosion: a Manual for the Assessment and Management of Agricultural Land at Risk of Water Erosion in Lowland England. Revised September 2005. Department for Environment, Food and Rural Affairs, London] sets out a system of risk-assessment, including ranking of crops susceptible to erosion and anti-erosion measures, that may be selected. We assess this system using field data for an area of erodible soils in the Rother valley, Sussex. The Defra approach correctly identifies most at-risk fields and, taken together with land-use maps, allows non-compliance with advice to be highlighted. We suggest a simple extension to the system which would further identify at-risk fields in terms of possible damage to roads and rivers from muddy runoff. The increased risk of erosion in the study area is associated with certain crops: potatoes, winter cereals, maize and grazed turnips and seems unlikely to be the result of changes in rainfall which over the last 130 years are minimal. We have not evaluated proposed anti-erosion measures in the area because few have been put into practice. The European Water Framework Directive will increasingly focus attention on agricultural fields as a source of river pollution. Assessing the risk of erosion and the need for field testing of suggested approaches, are not simply issues for the EU, but for the management of global agricultural systems.     

“Safety is everyone's job:” The key to safety on a large university construction site

Problem

Construction risk management is challenging.

Method

We combined data on injuries, costs, and hours worked, obtained through a Rolling Owner-Controlled Insurance Program (ROCIP), with data from focus groups, interviews, and field observations, to prospectively study injuries and hazard control on a large university construction project.

Results

Lost-time injury rates (1.0/200,000 hours worked) were considerably lower than reported for the industry, and there were no serious falls from height. Safety was considered in the awarding of contracts and project timeline development; hazard management was iterative. A top-down management commitment to safety was clearly communicated to, and embraced by, workers throughout the site.

Discussion and Impact

A better understanding of how contracting relationships, workers' compensation, and liability insurance arrangements influence safety could shift risk management efforts from worker behaviors to a broader focus on how these programs and relationships affect incentives and disincentives for workplace safety and health.     

Interacting effects of sulphate pollution, sulphide toxicity and eutrophication on vegetation development in fens: A mesocosm experiment

Both eutrophication and SO₄ pollution can lead to higher availability of nutrients and potentially toxic compounds in wetlands. To unravel the interaction between the level of eutrophication and toxicity at species and community level, effects of SO₄ were tested in nutrient-poor and nutrient-rich fen mesocosms. Biomass production of aquatic and semi-aquatic macrophytes and colonization of the water layer increased after fertilization, leading to dominance of highly competitive species. SO₄ addition increased alkalinity and sulphide concentrations, leading to decomposition and additional eutrophication. SO₄ pollution and concomitant sulphide production considerably reduced biomass production and colonization, but macrophytes were less vulnerable in fertilized conditions. The experiment shows that competition between species, vegetation succession and terrestrialization are not only influenced by nutrient availability, but also by toxicity, which strongly interacts with the level of eutrophication. This implies that previously neutralized toxicity effects in eutrophied fens may appear after nutrient reduction measures have been taken.     

What determines the breadth and depth of Zambia's backward linkages to copper mining? The role of public policy and value chain dynamics

This paper investigates the dynamics of upstream linkages development to copper mining in Zambia. The breadth and depth of the local mining supply chain was deeply shaped by policies adopted in the 1990s under the Structural Adjustment Programme. These policies succeeded in attracting much-needed FDI in the mining sector, including Chinese and Indian FDI, but had a negative impact on the level of value-addition undertaken by local suppliers. In the post-privatisation era, the dynamics of the local supply chain suggest that supply firms' upgrading and sales growth were determined by firm ownership and value chain governance. In fact, forward linkages to buyers other than Chinese and Indian mining companies, and backward linkages to parent companies and technology providers were critical in supporting supply firms' success in the mining value chain.     

Evaluation of OC/EC Speciation by Thermal Manganese Dioxide Oxidation and the IMPROVE Method

Abstract

Ambient particulate samples are routinely analyzed for organic and elemental carbon (OC/EC) using either thermal manganese dioxide oxidation (TMO) or thermal volatil-ization-pyrolysis correction methods, such as the Inter-agency Monitoring of PROtected Visual Environments (IMPROVE) method with correction by reflectance, or a variation of the National Institute of Occupational Safety and Health (NIOSH) Method 5040 using thermal optical transmittance (TOT). With TMO, EC is modeled after the oxidation properties of submicron graphite and needle coke by MnO₂, and is the fraction of total carbon (TC) that is not oxidized at >525 °C. In thermal volatilization methods, EC is the fraction of TC that accounts for the light extinction properties of the sample at the start of analysis. Chow et al. (2001) compared IMPROVE and NIOSH methods implemented on the same instrument using 60 samples of various types and found that NIOSH EC was lower than IMPROVE. This study compares total, organic, and elemental carbon measurements from the TMO and IMPROVE thermal optical reflectance (TOR) methods using a sample set consisting of 60 IMPROVE nonurban, 16 Korean urban, 10 Hong Kong urban, and 14 synthetic carbon black samples.