A CLOSED SYSTEM SAMPLE TRANSFER DEVICE FOR VOLATILE ORGANIC COMPOUNI)S1

ABSTRACT: A sample transfer device was designed to provide a closed loop sampling system between a ground water sampling pump and a 40 ml volatile organic compound (VOC) vial. The same attachment can also be used with a bailer. The unit is constructed of a poly-tetrafluoroethylene (PTFE) body into which two stainless steel needles are press fitted. The needles puncture the Teflon septum of a vial; fluid flows through the longer needle into the vial and exits the vial from the shorter needle. The device eliminates sample transfer bias associated with head space, visible gas bubbles, and atmospheric contamination. Field sampling designed to determine differences in trichloroethylene (TCE) concentrations presumedly due to the device were statistically significant in one case, and insignificant in the second.     

Reducing the Risk of Accidental Death Due to Vehicle-Related Carbon Monoxide Poisoning

ABSTRACT

Emissions of carbon monoxide (CO) from motor vehicles cause several hundred accidental fatal poisonings annually in the United States. The circumstances that could lead to fatal poisonings in residential settings with motor vehicles as the source of CO were explored. The risk of death in a garage (volume = 90 m³) and a single-family dwelling (400 m³) was evaluated using a Monte Carlo simulation with varying CO emission rates and ventilation rates. Information on emission rates was obtained from a survey of motor vehicle exhaust gas composition under warm idle conditions in California, and information on ventilation rates was obtained from a summary of published measurements in the U.S. housing stock. The risk of death ranged from 16 to 21% for a 3-hr exposure in a garage to 0% for a 1-hr exposure in a house. Older vehicles were associated with a disproportionately high risk of death. Removing all pre-1975 vehicles from the fleet would reduce the risk of death by one-fourth to two-thirds, depending on the exposure scenario. Significant efforts have been made to control CO emissions from motor vehicles with the goal of reducing CO concentrations in outdoor air. Substantial public health benefit could also be obtained if vehicle control measures were designed to take account of acute CO poisonings explicitly.     

Evaluation of wireless sensor networks (WSNs) for remote wetland monitoring: design and initial results

Here, we describe and evaluate two low-power wireless sensor networks (WSNs) designed to remotely monitor wetland hydrochemical dynamics over time scales ranging from minutes to decades. Each WSN (one student-built and one commercial) has multiple nodes to monitor water level, precipitation, evapotranspiration, temperature, and major solutes at user-defined time intervals. Both WSNs can be configured to report data in near real time via the internet. Based on deployments in two isolated wetlands, we report highly resolved water budgets, transient reversals of flow path, rates of transpiration from peatlands and the dynamics of chromophoric-dissolved organic matter and bulk ionic solutes (specific conductivity)—all on daily or subdaily time scales. Initial results indicate that direct precipitation and evapotranspiration dominate the hydrologic budget of both study wetlands, despite their relatively flat geomorphology and proximity to elevated uplands. Rates of transpiration from peatland sites were typically greater than evaporation from open waters but were more challenging to integrate spatially. Due to the high specific yield of peat, the hydrologic gradient between peatland and open water varied with precipitation events and intervening periods of dry out. The resultant flow path reversals implied that the flux of solutes across the riparian boundary varied over daily time scales. We conclude that WSNs can be deployed in remote wetland-dominated ecosystems at relatively low cost to assess the hydrochemical impacts of weather, climate, and other perturbations.     

Development of a robust chromatographic method for the detection of chlorophenols in cork oak forest soils

A major concern for the cork and wine industry is ‘cork taint’ which is associated with chloroanisoles, the microbial degradation metabolites of chlorophenols. The use of chlorophenolic compounds as pesticides within cork forests was prohibited in 1993 in the European Union (EU) following the introduction of industry guidance. However, cork produced outside the EU is still thought to be affected and simple, robust methods for chlorophenol analysis are required for wider environmental assessment by industry and local environmental regulators. Soil samples were collected from three common-use forests in Tunisia and from one privately owned forest in Sardinia, providing examples of varied management practice and degree of human intervention. These provided challenge samples for the optimisation of a HPLC-UV detection method. It produced recoveries consistently >75 % against a soil CRM (ERM-CC008) for pentachlorophenol. The optimised method, with ultraviolet (diode array) detection is able to separate and quantify 16 different chlorophenols at field concentrations greater than the limits of detection ranging from 6.5 to 191.3 μg/kg (dry weight). Application to a range of field samples demonstrated the absence of widespread contamination in forest soils at sites sampled in Sardinia and Tunisia.     

The development of psychological contract breach and violation: a longitudinal study

This study examines factors affecting employees' perceptions that their psychological contract has been breached by their organization, and factors affecting whether this perception will cause employees to experience feelings of contract violation. Data were obtained from 147 managers just prior to their beginning of new job (time 1) and 18 months later (time 2). It was found that perceived contract breach at time 2 was more likely when organizational performance and self‐reported employee performance were low, the employee had not experienced a formal socialization process, the employee had little interaction with organizational agents prior to hire, the employee had a history of psychological contract breach with former employers, and the employee had many employment alternatives at the time of hire. Furthermore, perceived breach was associated with more intense feelings of violation when employees both attributed the breach to purposeful reneging by the employer and felt unfairly treated in the process. Theoretical and practical implications of these results are discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Environmentalism and elitism: a conceptual and empirical analysis

The frequent charge that environmentalism is elitist is examined conceptually and empirically. First, the concept of elitism is analyzed by distinguishing between three types of accusations made against the environmental movement: (a)compositional elitism suggests that environmentalists are drawn from privileged socioeconomic strata, (b)ideological elitism suggests that environmental reforms are a subterfuge for distributing benefits to environmentalists and/or costs to others, and (c)impact elitism suggests that environmental reforms, whether intentionally or not, do in fact have regressive social impacts.The evidence bearing on each of the three types of elitism is examined in some detail, and the following conclusions are drawn: Compositional elitism is an exaggeration, for although environmentalists are typically above average in socioeconomic status (as are most sociopolitical activists), few belong to the upper class. Ideological elitism may hold in some instances, but environmentalists have shown increasing sensitivity to equity concerns and there is little evidence of consistent pursuit of self-interest. Impact elitism is the most important issue, and also the most difficult to assess. It appears that there has been a general tendency for environmental reforms to have regressive impacts. However, it is increasingly recognized that problems such as workplace pollution and toxic waste contamination disproportionately affect the lower socioeconomic strata, and thus reforms aimed at such problems will likely have more progressive impacts.This is Michigan Agricultural Experiment Station Journal article no. 11508.     

Performance optimisation of a passive sampler for monitoring hydrophobic organic pollutants in water

The performance of an integrative passive sampler that consists of a C18 Empore disk sorbent receiving phase fitted with low density polyethylene membrane was optimised for the measurement of time-weighted average concentrations of hydrophobic micropollutants in water. A substantial improvement of sampling characteristics including the rate of sampling and the sampling precision was achieved by decreasing the internal sampler resistance to mass transfer of hydrophobic organic chemicals. This was achieved by adding a small volume of n-octanol, a solvent with high permeability (solubility [times] diffusivity) for target analytes, to the interstial space between the receiving sorbent phase and the polyethylene diffusion-limiting membrane.     

Responses of Desert Annual Plants to Ozone and Water Stress in an in situ Experiment

Desert winter annual plants: Camissonia claviformis, C. hirtella, Caulanthus cooperi, Chaneactis carphoclinia, C. stevioides, Cryptantha angustifolia, C. pterocarya, Erodium cicutarium, Festuca octoflora, Lupinus concinnus, Oenothera californica, Plantago insularis, Platystemon californica, Salvia columbariae, Thelypodium lasiophyllum, and Thysanocarpus curvipes growing on irrigated and non-irrigated plots were exposed in situ to elevated levels of ozone dispensed from an open air exposure system. Plants were exposed intermittently to a gradient of ozone of concentrations ranging between 44 and 133 ppb (nL L^?1) for 35 h over a total of 216 h. Only three species were injured by ozone at the highest ozone concentrations. Leaf injury to C. claviformis—2 percent total foliar injury (TFI), C. hirtella—1 percent TFI, and Erodium cicutarium—2 percent TFI, developed at the highest ozone concentrations. Leaf injury to these species was similar on the irrigated and nonirrigated plots. Leaf water potential and stomatal conductance significantly decreased in C. claviformis, and C. hirtella due to water stress but not ozone. Similar trend for net photosynthesis was also determined. The highest water potential and stomatal conductance values as well as the largest differences in water potential between irrigated and non-irrigated plants were found in the morning.     

Effectiveness of porous covers for control of ammonia, reduced sulfur compounds, total hydrocarbons, selected volatile organic compounds, and odor from hog manure storage lagoons

Anaerobic lagoons are a major source of odor at concentrated animal feeding operations. Seven different kinds of artificial (geotextile and polyethylene foam) and natural (straw and redwood) permeable lagoon covers were evaluated for their potential to reduce odorous emissions generated by anaerobic waste lagoons. A novel floating sampling raft was constructed and used to simultaneously evaluate the effectiveness of lagoon covers on an operating swine waste lagoon. The air collected from the raft was evaluated for odor, total reduced sulfur (TRS) compounds, ammonia, total hydrocarbons, dimethyldisulfide, and trimethylamine. The emission rates from the lagoon were highly variable both temporally and spatially. All of the lagoon covers substantially reduced TRS emissions and odor. Geotextile fabric and a recycled foam cover exhibited the greatest reduction in total hydrocarbon emissions; natural covers were less effective. Because of consistently low emission rates of ammonia, no statistically significant reduction of ammonia emissions were observed from any of the lagoon covers.