Stockpiles of obsolete pesticides and cleanup priorities: A methodology and application for Tunisia

Obsolete pesticides have accumulated in almost every developing country or economy in transition over the past several decades. Concerned about the risks these chemicals pose to nearby residents, public health and environmental authorities are eager to reduce health threats by removing and decontaminating stockpile sites. However, there are many sites, cleanup can be costly, and public resources are scarce, so decision makers need to set priorities. Under these conditions, it seems sensible to develop a methodology for prioritizing sites and treating them sequentially, as budgetary resources permit.This paper presents a new methodology that develops a cleanup priority index for 1915 metric tons of obsolete pesticide formulations at 197 stockpile sites in Tunisia. The approach integrates information on populations at risk, their proximity to stockpiles, and the relative toxic hazards of the stockpiles. What emerges from the Tunisia results is a strategy for sequentially addressing all 197 sites to rapidly reduce potential health damage in a cost-effective way.     

Predictors of conviction and sentencing of DWI offenders in a New Mexico County

OBJECTIVE: To analyze predictors of conviction and dismissal of individuals charged with DWI, and predictors of the sentences of those who are convicted. METHODS: Data come from the Citation Tracking System of the State of New Mexico's Motor Vehicle Division and includes information on all individuals who were arrested for DWI in San Juan County between August 1994 and December 2000. Independent variables were: age, gender, race/ethnicity, waiver of right to an attorney, court of arraignment, year of arrest, BAC, and number of prior DWI arrests. Dependent variables were: (1) conviction or dismissal, (2) jail or no jail, (3) incarceration/treatment or not, (4) fine or no fine, (5) length of jail sentence, (6) waived right of attorney, and (7) magnitude of fine. Multiple linear and logistic regression was used in the analyses. RESULTS: Use of an attorney is associated with reduced likelihood of conviction and, if convicted, in reduced likelihood of jail sentence and reduced jail time, but greater likelihood and magnitude of a fine. Native Americans were more likely than Hispanics and non-Hispanic whites to waive their right to an attorney. Native Americans were most likely to be sentenced to the detention/treatment program. BAC and number of prior arrests were each positively associated with increased likelihood of conviction and more severe sentences. There is also substantial variability in severity of sentencing among courts. CONCLUSION: Likelihood of conviction and severity of sentences are both determined by extra-legal factors, resulting in inconsistent application of the law. This may in turn contribute to a lack of compliance with laws related to DWI.     

Orchid bees don't need orchids: evidence from the naturalization of an orchid bee in Florida

Almost 200 species of orchid bees are the exclusive pollinators of nearly 700 specialized orchids in the neotropics. This well-known mutualism involves orchids, called perfume orchids, which produce species-specific blends of floral fragrances, and male orchid bees, which collect and use these fragrance compounds during their courtship. We report here the naturalization of an orchid bee, Euglossa viridissima, in southern Florida, USA, where perfume orchids are absent. Chemical analysis of the contents of the fragrance storage organs in the hind tibias of 59 male bees collected in Florida identified 55 fragrance compounds, including 27 known from the perfumes of nine species of E. viridissima's orchid mutualists in Mesoamerica. Aromatic leaves, such as basil, were found to be important surrogate sources of needed fragrance compounds in Florida. The bee's ability to live and become abundant in the absence of its orchid mutualists suggests that the orchid bee-perfume orchid mutualism may be facultative for the bees, even though it is obligatory for the orchids. This invasive bee visits and potentially pollinates the flowers of many plants in Florida, behavior that could promote the abundance of selected exotic and native species.     

Urbanized landscapes favored by fig-eating birds increase invasive but not native juvenile strangler fig abundance

Propagule pressure can determine the success or failure of invasive plant range expansion. Range expansion takes place at large spatial scales, often encompassing many types of land cover, yet the effect of landscape context on propagule pressure remains largely unknown. Many studies have reported a positive correlation between invasive plant abundance and human land use; increased propagule pressure in these landscapes may be responsible for this correlation. We tested the hypothesis that increased rates of seed dispersal by fig-eating birds, which are more common in urban habitats, result in an increase in invasive strangler fig abundance in landscapes dominated by human land use. We quantified abundance of an invasive species (Ficus microcarpa) and a native species (F. aurea) of strangler fig in plots spanning the entire range of human land use in South Florida, USA, from urban parking lots to native forest. We then compared models that predicted juvenile fig abundance based on distance to adult fig seed sources and fig-eating bird habitat quality with models that lacked one or both of these terms. The best model for juvenile invasive fig abundance included both distance to adult and fig-eating bird habitat terms, suggesting that landscape effects on invasive fig abundance are mediated by seed-dispersing birds. In contrast, the best model for juvenile native fig abundance included only presence/absence of adults, suggesting that distance from individual adult trees may have less effect on seed limitation for a native species compared to an invasive species undergoing range expansion. However, models for both species included significant effects of adult seed sources, implying that juvenile abundance is limited by seed arrival. This result was corroborated by a seed addition experiment that indicated that both native and invasive strangler figs were strongly seed limited. Understanding how landscape context affects the mechanisms of plant invasion may lead to better management techniques. Our results suggest that prioritizing removal of adult trees in sites with high fig-eating bird habitat may be the most effective method to control F. microcarpa abundance.     

FINANCING FEDERAL WATER DEVELOPEMNT PROJECTS AND SHARING THE COSTS1

ABSTRACT: The Federal Government's interest and involvement in water resource development in discussed in the context of project financing and cost sharing. After drawing a clear distinction between the two issues - who puts up the money, and who repays over time - the authors survey a number of Federal acts from which have evolved nearly 200 separate cost-sharing rules. Selected cost sharing and financing issues discussed include consistency in policies, rehabilitation of urban water supply systems, multipurpose water quality projects, and ground water management. Two proposals for cost/finance sharing reform introduced in the 96th Congress are discussed in detail and their impacts compared with current policy. The joint venture approach (Administration proposal) results in an effective composite cost share which changes significantly but not drastically (from 19 to 35 percent non-Federal share for a hypothetical project). The block grant approach (Domenici-Moynihan proposal) would alter the regional distribution of Federal water developement funding from the South and West to the Northwest and North Central States.     

Radioactivity in rainwater following the chernobyl accident

Summary Rainfall is a widely-acknowledged vehicle for the removal and deposition at ground level of atmospheric-borne materials. The events following the Chernobyl accident demonstrated once again the importance of atmospheric conditions in dispersing, transporting and depositing pollutants. Much attention has been paid to the contamination of vegetation and food products, yet the quality of the contaminated rainwater has been overlooked. This paper reports and summarises the findings from Great Britain and Scandinavia and shows that the issue is far from simple or easily understood.Dennis Wheeler is a member of the academic staff in The Geography Department at Sunderland Polytechnic. Throughout this paper the identity of actual recording sites in the UK has not been specified, merely the regions from which the data were gathered. This is in accordance with the wishes of the National Radiological Protection Board, UK.     

Feasibility of ultraviolet-light-emitting diodes as an alternative light source for photocatalysis

The objective of this study was to determine whether ultraviolet-light-emitting diodes (UV-LEDs) could serve as an efficient photon source for heterogeneous photocatalytic oxidation (PCO). An LED module consisting of 12 high-power UV-A (lambda max = 365 nm) LEDs was designed to be interchangeable with a UV-A fluorescent black light blue (BLB) lamp for a bench scale annular reactor packed with silica-titania composite (STC) pellets. Lighting and thermal properties of the module were characterized to assess its uniformity and total irradiance. A forward current (I(F)) of 100 mA delivered an average irradiance of 4.0 mW cm(-2) at a distance of 8 mm, which is equivalent to the maximum output of the BLB, but the irradiance of the LED module was less uniform than that of the BLB. The LED and BLB reactors were tested for the oxidization of ethanol (50 ppm(v)) in a continuous-flow-through mode with 0.94 sec residence time. At the same average irradiance, the UV-A LED reactor resulted in a lower CO2 production rate (19.8 vs. 28.6 nmol L(-1) s(-1)), lower ethanol removal (80% vs. 91%), and lower mineralization efficiency (28% vs. 44%) than the UV-A BLB reactor. Ethanol mineralization was enhanced with the increase of the irradiance at the catalyst surface. This result suggests that reduced ethanol mineralization in the LED reactor relative to the BLB reactor at the same average irradiance could be attributed to the nonuniform irradiance over the photocatalyst, that is, a portion of the catalyst was exposed to less than the average irradiance. The potential of UV-A LEDs may be fully realized by optimizing the light distribution over the catalyst and utilizing their instantaneous "on" and "off" feature for periodic irradiation. Nevertheless, our results also showed that the current UV-A LED module had the same wall plug efficiency (WPE) of 13% as that of the UV-A BLB, demonstrating that UV-A LEDs are a viable photon source both in terms of WPE and PCO efficiency.     

Back-extrapolation of estimates of exposure from current land-use regression models

Land use regression has been used in epidemiologic studies to estimate long-term exposure to air pollution within cities. The models are often developed toward the end of the study using recent air pollution data. Given that there may be spatially-dependent temporal trends in urban air pollution and that there is interest for epidemiologists in assessing period-specific exposures, especially early-life exposure, methods are required to extrapolate these models back in time. We present herein three new methods to back-extrapolate land use regression models. During three two-week periods in 2005–2006, we monitored nitrogen dioxide (NO₂) at about 130 locations in Montreal, Quebec, and then developed a land-use regression (LUR) model. Our three extrapolation methods entailed multiplying the predicted concentrations of NO₂ by the ratio of past estimates of concentrations from fixed-site monitors, such that they reflected the change in the spatial structure of NO₂ from measurements at fixed-site monitors. The specific methods depended on the availability of land use and traffic-related data, and we back-extrapolated the LUR model to 10 and 20 years into the past. We then applied these estimates to residential information from subjects enrolled in a case–control study of postmenopausal breast cancer that was conducted in 1996.Observed and predicted concentrations of NO₂ in Montreal decreased and were correlated in time. The estimated concentrations using the three extrapolation methods had similar distributions, except that one method yielded slightly lower values. The spatial distributions varied slightly between methods. In the analysis of the breast cancer study, the odds ratios were insensitive to the method but varied with time: for a 5 ppb increase in NO₂ using the 2006 LUR the odds ratio (OR) was about 1.4 and the ORs in predicted past concentrations of NO₂ varied (OR～1.2 for 1985 and OR～1.3–1.5 for 1996). Thus, the ORs per unit exposure increased with time as the range and variance of the spatial distributions decreased, and this is due partly to the regression coefficient being approximately inversely proportional to the variance of exposure. Changing spatial variability complicates interpretation and this may have important implications for the management of risk. Further studies are needed to estimate the accuracy of the different methods.