Long-Term Trends in Ambient Lead Levels at Five Locations in New Jersey

The authors conducted a survey based on conjoint choice experiments in Milan, Italy, about mortality risk reductions delivered by hypothetical private behaviors and public programs, and used it to estimate the value of a prevented fatality (VPF) when the cause of death is cancer. Their estimate of the VPF is €4.2 million. The VPF is about €1 million larger when the risk reduction is delivered by a public program, but further analyses reveal that it is so only when the respondent believes that public programs are effective at reducing this particular type of mortality risk. This estimate of the VPF is higher than generic European Union–wide figures recommended by the European Commission Directorate-General for Environment (DG Environment) for environmental policy analyses, and is comparable to other VPFs that are appropriate for Italy, hazardous waste regulations, and enforcement-based cleanup programs. The authors use their VPF to compute the benefits of addressing leaking landfills, illegal disposal of hazardous wastes, and poor hazardous waste management practices in the provinces of Naples and Caserta in southern Italy. The authors also examine the importance of the discount rates, since the mortality benefits of remediation begin in 20 yr and are assumed to continue over 30 yr.

Implications: Cost-benefit analysis that includes monetized nonmarket goods and services such as adverse health and premature mortality effects has become a standard tool in project appraisal and policy decision-making. The authors' estimates of the mortality benefits of cleaning up hazardous waste sites in a region of southern Italy are much larger than previous calculations that relied on the guidelines by DG Environment, raising concerns that using one VPF for all member countries of the European Union, and/or VPF figures estimated in a private risk reduction setting, might considerably underestimate the benefits of cleanup policies.     

Application of Sample Selection Model in Estimating Response Functions for Nitrate Percolation

The Seymour aquifer region of Texas has been identified as containing elevated levels of nitrate in ground water. Various state and federal agencies are currently studying policy options for the region by gathering more site-specific information. However, because of lack of sufficient information, cause and effect relationships between water quality and agricultural practices have not been well established for the region. Some recently available biophysical simulation models have impressive capabilities in generating large amounts of data on environmental pollution resulting from agricultural production practices. In this study, the data generated by a biophysical simulation model were used to estimate the nitrate percolation response functions for the Seymour aquifer region. Interestingly, nitrate percolation values obtained from simulation models often comprise acensoredsample because the non-zero percolation values are only observed under certain climatic events and input levels. It has been shown in the econometric literature that the use of Ordinary Least Squares (OLS) on censored sample data produces biased and inconsistent parameter estimates. Thus, a sample selection model was used in this study to estimate the response functions for nitrate percolation. The study provides some insight into the relationship between nitrate percolation and agricultural production practices. In particular, the study demonstrates the potential of selected design standards in minimizing agricultural nonpoint-source (NPS) pollution for the study area.     

Stress,work and professional satisfaction and militancy among Canadian physicians

The introduction of a national health care system in Canada has resulted in regular and increasing conflict between the medical profession, government and other political actors. The present study utilizes a stressor–strain framework to understand physician militancy in Canada. Data were collected from 2087 men and women physicians using questionnaires completed anonymously. Four groups of predictor variables identified in previous research were considered: individual demographic characteristics, practice characteristics, work stressors, and work and professional satisfactions. Empirical support for the model was found. Each panel of predictor variables had significant and unique relationships with measures of physician militancy.     

Evaluation of Three Watershed‐Scale Pesticide Environmental Transport and Fate Models1

Abstract: The U.S. Environmental Protection Agency (USEPA) Office of Pesticide Programs (OPP) has completed an evaluation of three watershed‐scale simulation models for potential use in Food Quality Protection Act pesticide drinking water exposure assessments. The evaluation may also guide OPP in identifying computer simulation tools that can be used in performing aquatic ecological exposure assessments. Models selected for evaluation were the Soil Water Assessment Tool (SWAT), the Nonpoint Source Model (NPSM), a modified version of the Hydrologic Simulation Program‐Fortran (HSPF), and the Pesticide Root Zone Model‐Riverine Water Quality (PRZM‐RIVWQ) model. Simulated concentrations of the pesticides atrazine, metolachlor, and trifluralin in surface water were compared with field data monitored in the Sugar Creek watershed of Indiana’s White River basin by the National Water Quality Assessment (NAWQA) program. The evaluation not only provided USEPA with experience in using watershed models for estimating pesticide concentration in flowing water but also led to the development of improved statistical techniques for assessing model accuracy. Further, it demonstrated the difficulty of representing spatially and temporally variable soil, weather, and pesticide applications with relatively infrequent, spatially fixed, point estimates. It also demonstrated the value of using monitoring and modeling as mutually supporting tools and pointed to the need to design monitoring programs that support modeling.     

Competition,disturbance and local diversity patterns of substratum-bound clonal organisms: A simulation

We have conducted a series of simulations in order to compare the relative diversification effects of disturbance and intransitive (i.e., A > B, B > C but C > A) competition on a hypothetical set of clonal organisms. We found large significant differences between these two effects only when disturbance levels were low or absent. We suggest that natural assemblages should be examined for the frequency of intransitive interactions along disturbance gradients in order to assess the significance of these competitive relationships. We also argue that intransitive competition ought to be incorporated into nonequilibrium disturbance models; diversification effects of disturbance and intransitive competition need not be mutually exclusive.     

A study of diesel emissions on Drosophila

A sex-linked recessive lethal test was performed on male fruit flies of the species Drosophila melanogaster, (Oregon-R strain), exposed to an approximate five-fold dilution of exhaust from a diesel engine. The eight hour exposure was achieved by drawing diluted diesel exhaust from a three cubic meter stainless steel exposure chamber housing laboratory animals through a two liter reaction flask modified for use with Drosophila. A preconditioned sampling bag was used to collect the emissions after passing through the exposure chamber containing the flies. Results of analyses performed on the diesel exhaust mixture showed the following: carbon dioxide—0.17%, carbon monoxide—12.2 ppm, hydrocarbons—11.6 ppm, nitrogen oxide—3.8 ppm, nitrogen dioxide—2.9 ppm, sulphur dioxide—1.0 ppm, and particulates—2.18 mg/m³. Two broods of the F₂ generation were investigated for the occurrence of recessive lethal events. These broods approximated the developing gametogenic stages of mature sperm (P₁ matings on days 2 and 3 postexposure) and spermatocytes (P₁ matings on days 8 and 9). Additionally, the F₃ generation was evaluated for the occurrence of mosaic recessive lethal events which might escape detection in the F₂ generation. An equal number of F₂ and F₃ flies for both broods served as concurrent controls. Results indicate that, under the conditions tested, the diesel exhaust did not increase the mutation frequency of the exposed flies (F₂ rate = 0.30%, F₃ rate = 0%) when compared to the concurrent controls (F₂ rate = 0.37%, F₃ rate = 0.15%).     

Selection, preparation, and disposal of sodium compounds for dry SOx scrubbers

A program has been initiated to assess an SO₂ removal method wherein dry powdered sodium compounds are injected into the gas stream ahead of the baghouse filter. The compounds are collected on the surface of the filter bags for reaction with the gaseous SO₂. Initial program efforts include a survey of suitable and available sodium compounds, methods of preparing the compounds for injection, and an invistigation of environmentally acceptable methods of disposal.