Mercury accumulation in caged Corbicula: rate of uptake and seasonal variation

The uptake and seasonal fluctuations of total mercury were followed in caged and uncaged Asiatic clams, Corbicula fluminea, over a 1-year period in South River, Virginia. Mercury was rapidly accumulated in clams transplanted from a nominally uncontaminated site into cages on the contaminated South River, reaching 0.99 μg g^???1 dry mass within the first month. Resident clams moved to cages had higher mercury contents after the first month (2.04 μg g^???1 dry mass) and at all subsequent times in the study. Large monthly fluctuations in mercury were noted for both resident caged and transplant caged clams with a notable peak occurring in early spring (4.31 μg g^???1 dry mass in resident caged clams). Tissue mass of caged clams steadily increased through the winter and early spring. Adjustment of mercury concentrations for tissue mass changes indicated that the changes in mercury contents were primarily due to uptake/release rather than changes in tissue mass (concentration/dilution). The present study demonstrates the utility of using caged Corbicula as mercury biomonitors and illustrates the importance of accounting for large, short-term changes of mercury content in Corbicula when designing long-term biomonitoring studies.     

A Preliminary Study of Particulate Emissions from Small Wood Stoves

This paper summarizes the methodology developed to analyze alternative oxidant control strategies of the 1979 Air Quality Plan for the San Francisco Bay Area. The analysis of alternative oxidant control strategies is a complex task, particularly when a grid-based photochemical model is the primary analysis tool. To handle quantitatively spatial and temporal variations in emissions under both existing and projected future conditions, as well as to simulate the effects of a wide variety of control strategies, a system of computer-based models was assembled. The models projected and distributed a number of variables in space and time: population, employment, housing, land use, transportation, emissions, and air quality. Given time and budget constraints, an approach to maximizing the information return from a limited number of model runs was developed. The system was applied in three sequences to determine (1) what future air quality would be if no further controls were implemented, (2) the degree of hydrocarbon and NO_x emission control necessary to attain the oxidant standard, and (3) the effectiveness of alternative stationary source, mobile source, transportation and land use control strategies in contributing to attainment and maintenance of the oxidant standard.

A number of significant modeling assumptions had to be developed in order properly to interpret the modeled results in the context of the oxidant standard. In particular, a Larsen-type analysis was used to relate modeled atmospheric conditions to “worst case” conditions, and a proportional assumption was made to compensate model results for an imperfect validation. The specification of initial and boundary conditions for future year simulations was found to be a problem in need of further research.     

Unique products from the reaction of naphthalene with the hydroxyl radical

Many of the products of the reaction of naphthalene (Naph) with the OH radical in a reaction chamber were identified. Previously unidentified products included 1,2-naphthoquinone (NQ), oxygenated indenes and benzopyrones. Possible pathways for the formation of 1,2-NQ and 1,4-NQ are proposed. In the chamber reactions, more 1,2-NQ than 1,4-NQ partitioned to the particle phase. From this result we infer that, in the atmosphere, the percentage of 1,2-NQ in the particle phase should be greater than that for the 1,4-NQ. Because both of these compounds are considered to be toxic, and since they appear in both the gas and particle phases in the reaction chamber, and by implication in the atmosphere, it is considered important that both the gas and particle phases of these two compounds should be measured to assess their impact on human health.     

Prenatal and postnatal management of omphalocele

Omphalocele is one of the most common abdominal wall defects seen in the prenatal period. Once this diagnosis is confirmed, it is important to check the fetal karyotype and thoroughly assess the fetus for other malformations. Prenatal management involves serial assessment of fetal growth and prenatal testing to ensure fetal well-being. Closure of the abdominal wall and replacement of organs into the abdominal cavity can be done directly if the omphalocele is small or in a staged manner if the omphalocele is large. Successful outcomes for these neonates can be optimized with a multidisciplinary team approach to prenatal and postnatal management. Copyright © 2008 John Wiley & Sons, Ltd.     

In utero therapy for fetal thoracic abnormalities

Fetal thoracic lung anomalies are rare. The specific diagnosis can be made by utilizing ultrasound, magnetic resonance imaging (MRI), and Doppler studies. Perinatal surveillance is required for large lesions and mediastinal shift regardless of the pathological diagnosis. These can cause physiological changes in the cardiovascular system with resulting hydrops. In utero therapies are variable but with no large randomized trials to compare risks and benefits. In most cases of fetal lung lesions, continued observation with postnatal therapy is the outcome. When fetal hydrops is present or impending, in utero fetal therapy is required to try to reverse that pathological course associated with fetal or neonatal death. Maternal morbidity is increased with the development of MIRROR syndrome following the presence of long-standing fetal hydrops and possible surgical procedures. Copyright © 2008 John Wiley & Sons, Ltd.     

A Study of Cooling Pond Fog Generation

Airborne particulate and soil materials sampled in the vicinity of a lead/zinc smelter and subsequently digested In nitric-perchloric acids have been analyzed using an inductively coupled plasma-atomic emission spectrometer (ICP/AES). The samples were collected in two communities; a study community situated immediately adjacent to the smelter complex and a control community some 50 kilometers distant. Enrichment of airborne as well as soil materials is discussed and there is evidence of lead, zinc, copper, cadmium, arsenic, and antimony enrichment from the smelting processes. In addition, an aqueous extraction of the airborne materials isolated sulfate, nitrate, fluoride, and ammonia and gave evidence of enrichment due to fugitive SO _x , NO _x , HF, and NH₃ gaseous emissions.     

Effects of cadmium,zinc, copper and manganese on hepatic parenchymal cell gluconeogenesis

Abstract

The effects of divalent cations on gluconeogenesis in enzy‐matically isolated rat hepatic parenchymal cells were examined. Cadmium, zinc and copper decreased glucose production from lactate (10 mM). However, manganese at 0.05 to 1.0 mM levels stimulated gluconeogenesis by the cells and reduced the effects of the Cd⁺², Zn⁺² and Cu⁺² on gluconeogenesis. The results indicate that under these in vitro conditions the cations altered an aspect of hepatic function—gluconeogenesis from lactate.     

A Regional Waterway Management System for Balancing Recreational Boating and Resource Protection

Florida’s coasts have been transformed over the past three decades as population growth and unprecedented demand for individual shore access to bays and estuaries led to the creation of residential canal developments. Thousands of miles of channels and basins were dredged as a by-product of this urbanization process. The navigable waterways that resulted are now being stressed by increasing boat traffic and canal-side activities. Recognizing their common goal to preserve the recreational and ecological value of southwest Florida waterways, the Florida Department of Environmental Protection, the four-county West Coast Inland Navigation District, and the University of Florida Sea Grant College Program signed a Memorandum of Agreement. The signatories agreed to develop a science-based Regional Waterway Management System (RWMS), which is a new approach to waterway planning and permitting based on carefully mapped channel depths, a census of actual boat populations, and the spatial extent of natural resources. The RWMS provides a comprehensive, regional overview of channel conditions and the geographic distribution and severity of existing impediments to safe navigation and resource protection. RWMS information and analyses result in regional-scale permitting to accommodate water-dependent uses while minimizing environmental impacts and reducing public expenditures. Compared with traditional approaches to waterway management, the science-based RWMS is relatively unbiased, objective, transparent, ecologically sound, and fiscally prudent.     

Discussion1-“Stream Temperature Relationships to Forest Harvest in Western Washington” by Michael M. Pollock,Timothy J. Beechie,Martin Liermann,and Richard E. Bigley2

Ice, George G., George W. Brown, John A. Gravelle, C. Rhett Jackson, Jeffrey T. Light, Timothy E. Link, Douglas J. Martin, Dale J. McGreer, and Arne E. Skaugset, 2010. Discussion –“Stream Temperature Relationships to Forest Harvest in Western Washington” by Michael M. Pollock, Timothy J. Beechie, Martin Liermann, and Richard E. Bigley. Journal of the American Water Resources Association (JAWRA) 46(4): 838-842. DOI: 10.1111/j.1752-1688.2010.00441.x