Impacts of pesticides in a Central California estuary

Recent and past studies have documented the prevalence of pyrethroid and organophosphate pesticides in urban and agricultural watersheds in California. While toxic concentrations of these pesticides have been found in freshwater systems, there has been little research into their impacts in marine receiving waters. Our study investigated pesticide impacts in the Santa Maria River estuary, which provides critical habitat to numerous aquatic, terrestrial, and avian species on the central California coast. Runoff from irrigated agriculture constitutes a significant portion of Santa Maria River flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in this watershed. Our study extended into the Santa Maria watershed coastal zone and measured pesticide concentrations throughout the estuary, including the water column and sediments. Biological effects were measured at the organism and community levels. Results of this study suggest the Santa Maria River estuary is impacted by current-use pesticides. The majority of water samples were highly toxic to invertebrates (Ceriodaphnia dubia and Hyalella azteca), and chemistry evidence suggests toxicity was associated with the organophosphate pesticide chlorpyrifos, pyrethroid pesticides, or mixtures of both classes of pesticides. A high percentage of sediment samples were also toxic in this estuary, and sediment toxicity occurred when mixtures of chlorpyrifos and pyrethroid pesticides exceeded established toxicity thresholds. Based on a Relative Benthic Index, Santa Maria estuary stations where benthic macroinvertebrate communities were assessed were degraded. Impacts in the Santa Maria River estuary were likely due to the proximity of this system to Orcutt Creek, the tributary which accounts for most of the flow to the lower Santa Maria River. Water and sediment samples from Orcutt Creek were highly toxic to invertebrates due to mixtures of the same pesticides measured in the estuary. This study suggests that the same pyrethroid and organophosphate pesticides that have been shown to cause water and sediment toxicity in urban and agriculture water bodies throughout California, have the potential to affect estuarine habitats. The results establish baseline data in the Santa Maria River estuary to allow evaluation of ecosystem improvement as management initiatives to reduce pesticide runoff are implemented in this watershed.     

Fetal cells in the uterine cervix: a source for early non-invasive prenatal diagnosis

Various non-invasive techniques for prenatal diagnosis have been under investigation. We evaluated the success of fetal sexing using a non-invasive technique for obtaining fetal cells, uterine cervix brushing, in combination with FISH. Thirty pregnant women who completed between 6 and 10 weeks of gestation and who were scheduled to undergo pregnancy termination were included in the study. A Pap smear cytobrush was inserted through the external os to a maximum depth of 2 cm and removed while rotating it a full turn. The material that was caught on the brush was spread on four microscope slides. Two-color FISH was used for fetal sexing. Following pregnancy termination, a placental sample was used for full karyotyping. In 29/30 cases FISH diagnosis was confirmed by chromosomal analysis. The only male case in which a Y chromosome was not seen was from a pregnancy of 6 weeks 6 days gestational age. One case was mosaic of 46,XY/47,XXY (25%). In most cases (7/13) the Y chromosome was already identified in the first analyzed slide. With the use of a cytobrush fetal cells can be easily obtained for the purpose of prenatal diagnosis of chromosomal disorders. Copyright © 2001 John Wiley & Sons, Ltd.     

The Aerosol Research and Inhalation Epidemiology Study (ARIES): PM25 Mass and Aerosol Component Concentrations and Sampler Intercomparisons

ABSTRACT

The Aerosol Research and Inhalation Epidemiology Study (ARIES) was designed to provide high-quality measurements of PM₂₅, its components, and co-varying pollutants for an air pollution epidemiology study in Atlanta, GA.

Air pollution epidemiology studies have typically relied on available data on particle mass often collected using filter-based methods. Filter-based PM_2.5 sampling is susceptible to both positive and negative errors in the measurement of aerosol mass and particle-phase component concentrations in the undisturbed atmosphere. These biases are introduced by collection of gas-phase aerosol components on the filter media or by volatilization of particle phase components from collected particles. As part of the ARIES, we collected daily 24-hr PM_2.5 mass and speciation samples and continuous PM_2.5 data at a mixed residential-light industrial site in Atlanta. These data facilitate analysis of the effects of a wide variety of factors on sampler performance. We assess the relative importance of PM_2.5 components and consider associations and potential mechanistic linkages of PM_2.5 mass concentrations with several PM_2.5 components.

For the 12 months of validated data collected to date (August 1, 1998-July 31, 1999), the monthly average Federal Reference Method (FRM) PM_{2 5} mass always exceeded the proposed annual average standard (12-month average = 20.3 ± 9.5 ug/m³). The particulate SO₄ ^2- fraction (as (NH₄)₂SO₄) was largest in the summer and exceeded 50% of the FRM mass. The contribution of (NH₄)₂SO₄ to FRM PM_2.5 mass dropped to less than 30% in winter. Particu-late NO₃ ^- collected on a denuded nylon filter averaged 1.1 ± 0.9 ug/m³. Particle-phase organic compounds (as organic carbon × 1.4) measured on a denuded quartz filter sampler averaged 6.4 ± 3.1 ug/m³ (32% of FRM PM_{2 5} mass) with less seasonal variability than SO₄ ^2-.     

High-performance teams in wildlife conservation: A species reintroduction and recovery example

Reintroduction of animals to the wild to establish free-ranging viable populations is a valuable conservation tool, but ecological skills alone are not enough to ensure a successful reintroduction; also needed to do the work are effectively designed and managed programs. This article suggests general guidelines for organizing and managing reintroduction programs, reviews some basic organizational issues, and considers ways to develop high-performance teams The need to integrate reintroduction programs into their larger interorganizational context is discussed. The reintroduction program's structure must be appropriate for its function and should be properly staffed, led, and buffered from its political environment It should process information well, learn rapidly from its own mistakes, and be creative A high-performance team devotes most of its energies to solving external rather than internal problems     

Groundwater circulation well operation using wind turbine–generated energy

An investigation was conducted regarding the potential economic benefits associated with using a wind turbine to power a groundwater circulation well (GCW) at the former Nebraska Ordnance Plant Superfund site. The first phase of the investigation used a 10‐kilowatt‐rated grid inter‐tie wind turbine to partially offset the purchase of electricity from the utility company. The second phase consisted of the conversion of the grid inter‐tie system to an off‐grid system that stored energy using batteries. During the second phase, the GCW system was operated using either wind turbine power or utility power, and the other system components were operated using utility power. The study showed that a significant amount of power purchased from the utility company was used for nonessential purposes (other than operating the GCW pump and essential treatment components). One nonessential power consumer was the continuous heating of the equipment shelter for operator comfort during their 10‐minute visit every few days. Wind‐turbine reduction in utility power consumption was evaluated, and the operating time of a hypothetical system powered solely by the wind turbine was compared to the actual GCW operating time. This study indicates that retrofitting this GCW system did not economically offset power costs from a cheap, readily available grid system. Perhaps at a remote location with a more energy‐efficient design and operation and the inclusion of green power benefits (in some monetary amount), the wind turbine results will be more favorable. The study of a renewable energy application at the site highlighted opportunities for significant electrical energy savings regardless of the source of the electricity. © 2008 Wiley Periodicals, Inc.     

Report: Combustion Byproducts and Their Health Effects: Summary of the 10th International Congress

The 10th International Congress on Combustion Byproducts and their Health Effects was held in Ischia, Italy, from June 17-20, 2007. It is sponsored by the US NIEHS, NSF, Coalition for Responsible Waste Incineration (CRWI), and Electric Power Research Institute (EPRI). The congress focused on: the origin, characterization, and health impacts of combustion-generated fine and ultrafine particles; emissions of mercury and dioxins, and the development/application of novel analytical/diagnostic tools. The consensus of the discussion was that particle-associated organics, metals, and persistent free radicals (PFRs) produced by combustion sources are the likely source of the observed health impacts of airborne PM rather than simple physical irritation of the particles. Ultrafine particle-induced oxidative stress is a likely progenitor of the observed health impacts, but important biological and chemical details and possible catalytic cycles remain unresolved. Other key conclusions were: (1) In urban settings, 70% of airborne fine particles are a result of combustion emissions and 50% are due to primary emissions from combustion sources, (2) In addition to soot, combustion produces one, possibly two, classes of nanoparticles with mean diameters of?~10?nm and?~1?nm. (3) The most common metrics used to describe particle toxicity, viz. surface area, sulfate concentration, total carbon, and organic carbon, cannot fully explain observed health impacts, (4) Metals contained in combustion-generated ultrafine and fine particles mediate formation of toxic air pollutants such as PCDD/F and PFRs. (5) The combination of metal-containing nanoparticles, organic carbon compounds, and PFRs can lead to a cycle generating oxidative stress in exposed organisms.