Application of Pesticide Sprays to Fresh Produce: A Risk Assessment for Hepatitis A and <Emphasis Type="Italic">Salmonella</Emphasis>

The purpose of this study was to quantify the transfer of viral and bacterial pathogens in water used to dilute pesticides sprayed onto the surfaces of cantaloupe, iceberg lettuce, and bell peppers. The average percent transfer of bacteria was estimated to range from 0.00021 to 9.4%, while average viral transfer ranged from 0.055 to 4.2%, depending on the type of produce. Based on these values the concentrations of hepatitis A virus (HAV) and Salmonella in water necessary to achieve a 1:10,000 annual risk of infection were calculated. Under worst case scenario assumptions, in which a pesticide is applied on the same day that the produce is harvested and when maximum transfer values are used, concentrations of 1.5 × 10⁻³ CFU Salmonella or 2.7 × 10⁻⁷ MPN HAV per 100 ml of the water used for application would result in 1:10,000 annual infection risk to anyone who consumes the fresh produce. If harvesting does not occur until at least 14 days after the application, to produce the same risk of infection, the numbers of Salmonella in 100 ml of water used to dilute the pesticides will be greater by up to five orders of magnitude, while the HAV numbers will have increased by up to two orders of magnitude. Based on the reported concentrations of enteric viruses in surface and ground waters in the United States, a 1:10,000 annual risk of infection could easily be exceeded with some groundwater sources used in the United States. To reduce the risks associated with the consumption of fresh produce, water used to prepare pesticides in spray applications should be evaluated for its microbiological quality.     

Winners and Losers in a World with Global Warming: Noncooperation, Altruism, and Social Welfare

In this paper, global warming is an asymmetric transboundary externality which benefits some countries or regions and harms others. We use a simple two-country model to analyze the effects of global warming on resource allocations, the global-warming stock, and national and global welfare.     

A multilevel analysis of procedural justice context

Using a multilevel framework, we hypothesized that both employee perceptions of procedural justice and a work unit level measure of procedural justice context would be associated with employee reports of job satisfaction and organizational commitment. Three hundred and twenty-three employees from 53 branches of a financial services organization were used to test this hypothesis. Hierarchical linear modeling analyses revealed that procedural justice context explained variance in employee job satisfaction beyond that accounted for by individual perceptions of procedural justice. With regard to organizational commitment, this hypothesis was not supported. The results are discussed in connection with contextual aspects of procedural justice. © 1998 John Wiley & Sons, Ltd.     

Spillover effects of yield-to-pedestrian channelizing devices

A great number of pedestrians are killed or injured in traffic crashes every year in the US. Vehicle crashes involving pedestrians are often more severe than other crashes because pedestrians are unprotected and are hence more likely to suffer injuries or death if struck by a motor vehicle. To improve pedestrian safety, a variety of treatments such as overhead flashing beacons, in-street crossing signs, in-roadway warning lights, and traffic calming measures have been used. One treatment, in-street yield-to-pedestrian channelizing devices (YTPCD), has been used in many states, including Pennsylvania, where approximately 10% of traffic crash fatalities are pedestrians each year.In an effort to improve pedestrian safety, the Pennsylvania Department of Transportation (PennDOT) has widely deployed YTPCD. This study examines the spillover (indirect) effects of such devices on motorist and pedestrian behavior. With data collected from eight sites that did not have but were in the vicinity of YTPCD implementations, analysis results show that such devices have significantly positive spillover effects on pedestrian safety at intersections, but they tend to have negative spillover effects at mid-block locations. Overall, the YTPCD appear to have a positive impact on changing motorist and pedestrian behavior, and merit consideration for future usage of this type of device.     

Measurements of fog water interception by shrubs on the California central coast

Fog water deposition may be an important component of the water budget of herbaceous-shrub ecosystems on the central and southern coastal regions of California. This paper presents the first analysis of measured fog water drip rates and meteorological controls in shrublands of Big Sur, California. Seasonal totals of 1255 mm and 306 mm of fog water drip were recorded in 2014 and 2015 (respectively), for averaged fog deposition rates of 0.02–0.08 l m² hr.^?1 to the soil under shrub canopy cover. The diurnal patterns of fog water drip showed that the majority of all trough water collected under shrubs on no-rain days occurred between the hours of 11 PM and 9 AM. During the study period from June 1 to October 31 of both 2014 and 2015, soil water content decreased significantly from average levels of 4–6 % at the shrub canopy center and middle locations, through 2–3 % VWC at the shrub edge locations, to levels at or below 2 % at 2-m distance locations from the shrub edge in open grass cover. Based on these results, we conclude that detectable rates of shrub canopy fog interception help sustain elevated soil water levels under shrubs and aid woody vegetation survival through periods of low rainfall.     

Is habitat amount important for biodiversity in rocky shore systems? A study of South African mussel assemblages

Habitat-forming species on rocky shores are often subject to high levels of exploitation, but the effects of subsequent habitat loss and fragmentation on associated species and the ecosystem as a whole are poorly understood. In this study, the effects of habitat amount on the fauna associated with mussel beds were investigated, testing for the existence of threshold effects at small landscape scales. Specifically, the relationships between mussel or algal habitat amount and: associated biodiversity, associated macrofaunal abundance and density of mussel recruits were studied at three sites (Kidd’s Beach, Kayser’s Beach and Kini Bay) on the southern and south-eastern coasts of South Africa. Samples, including mussel-associated macrofauna, of 10 × 10 cm were taken from areas with 100 % mussel cover (Perna perna or a combination of P. perna and Mytilus galloprovincialis) at each site. The amount of habitat provided by mussels and algae surrounding the sampled areas was thereafter determined at the 4.0 m² scale. A number of significant positive relationships were found between the amount of surrounding mussel habitat and the abundances of several taxa (Anthozoa, Malacostraca and Nemertea). Likewise, there were positive relationships between the amount of surrounding algal habitat and total animal abundance as well as abundance of mussel recruits at one site, Kini Bay. In contrast, abundance of mussel recruits showed a significant negative relationship with the amount of mussel habitat at Kayser’s Beach. Significant negative relationships were also detected between the amount of mussel habitat and species richness and total abundance at Kidd’s Beach, and between amount of mussel habitat and the abundance of many taxa (Bivalvia, Gastropoda, Maxillopoda, Ophiuroidea, Polychaeta and Pycnogonida) at all three sites. No threshold effects were found, nor were significant relationships consistent across the investigated sites. The results indicate that the surrounding landscape is important in shaping the structure of communities associated with these mussel beds, with significant effects of the amount of surrounding habitat per se. The strength and the direction of habitat effects vary, however, between shores and probably with the scale of observation as well as with the studied dependent variables (e.g. diversity, abundance, mussel recruitment, species identity), indicating the complexity of the processes structuring macrofaunal communities on these shores.     

Predicting the acute lethality of a chlorinated benzene mixture in soils: a comparison of solid-phase microextraction,body residue,and solvent extraction techniques

When predicting the adverse effect(s) of chemical pollution on an exposed organism, a measurement of body residue is often considered a more accurate estimate of dose than those estimates derived from a solvent extraction or solid-phase microextraction of the polluted exposure medium. The magnitude of this perceived difference in accuracy, and thus the accuracy of the corresponding toxicity prediction, were investigated in the present two-phase study. In Phase I, an acute lethality response was correlated with dose estimates derived from body residue, solvent extraction, and SPME. In Phase II, acute lethality was predicted from Phase I data. The accuracy of Phase II toxicity predictions was determined by comparing predicted mortality to observed mortality. Although this study revealed that body residue indeed provided the most accurate prediction of toxicity, the margin of this comparatively greater accuracy suggests that alternative methods may provide equally viable dose estimates and, subsequently, equally viable toxicity predictions.