Temporal trends and spatial distribution of PCDD, PCDF, and PCB in pine and spruce shoots

In Germany, there is a lack of consistent and comparable data for the time dependent behaviour and spatial distribution of dioxin-like and indicator PCB in ambient air, deposition and plants. The aim of this study was to improve the data on PCDD/PCDF, dioxin-like PCB and non dioxin-like PCB in spruce and pine shoots from different locations and years by retrospective monitoring. The survey was conducted with archived samples of one-year old spruce shoots (Picea abies) and pine shoots (Pinus sylvestris) from the German environmental specimen bank. Two sets of samples from locations in urbanized areas in western and eastern Germany (Warndt and Duebener Heide Mitte, respectively) were investigated as time series. Additionally, spruce shoots from seven different rural locations sampled in the years 2000-2004 were analyzed in order to get an overview about the spatial distribution of PCB and PCDD/PCDF. The analytical results of the samples from the two urbanized areas clearly show that the atmospheric contamination with PCDD and PCDF has declined by about 75% between 1985 and 1997 at Warndt and about 40% between 1991 and 1997 at Duebener Heide. However, concentrations stayed virtually constant at both locations from 1997 to 2004 at a level of about 1 ng WHO-TEQ/kg dry matter (d.m.). Similarly, the investigation of spruce shoots from rural locations from 2000 to 2004 did not reveal a temporal trend at any site. PCDD/PCDF levels were between 0.1 and 1.0 ng WHO-TEQ/kg d.m. At the urbanized location Warndt the six indicator PCB as well as the 12 dioxin-like PCB according to WHO revealed a significant decline by more than 75% between 1985 and 1999. Thereafter, PCB levels stayed virtually constant. At the location Duebener Heide an overall decrease of PCB concentrations in pine shoots of about 60% was detected between 1991 and 2004. Spruce shoots from all locations showed a relevant contribution of dioxin-like PCB to the total WHO toxicity equivalent (PCDD/PCDF+PCB). In most samples, the contribution of dioxin-like PCB was between 21% and 41%. The TEQ contribution of PCB in the samples from three rural sites was higher and similar to the TEQ value of PCDD/PCDF. The investigated pine shoots from the urbanized site Duebener Heide showed a 15-28% contribution of dioxin-like PCB to total TEQ and thus lower than in spruce shoots from different locations. In all samples except one PCB 126 contributed to more than 80% to the PCB-TEQ.     

Matching innovations with potential users, a case study of potato IPM practices

Through interviews and mail surveys, Ohio potato (Solanum tuberosum) growers were surveyed concerning their willingness to adopt three cultural controls being developed for management of the Colorado potato beetle, Leptinotarsa decemlineata (Say), which had become increasingly difficult to control. The principal objective of the research was to obtain a deeper understanding of how farmers make decisions to adopt or not adopt new techniques and how these decisions are related to farmers' educational backgrounds and the way they currently manage their farms. The three cultural management options emphasized ecological approaches to habitat management rather than ecologically disruptive chemical control: (1) using host plants in overwintering sites to slow the spring movement of the beetles to potato fields, (2) using larger potato plants at field borders than in the center of the field as a spring trap crop, and (3) concentrating beetles in relatively small undefoliated areas to be killed with heat in late summer. Most respondents would not adopt these alternative pest management strategies, mainly because they perceived an unsatisfactory trade-off between logistic difficulties and expenses and population suppression they would achieve compared with traditional chemical control measures. Education correlated positively and experience in farming negatively with the willingness to try new pest management techniques. Additionally, growers responding more negatively to questions regarding integrated pest management strategies were more willing to experiment with the alternative techniques, a result attributed to either the survey design or an indication of experience with the more intensive management effort required for integrated pest management. This profile of potential innovators should be used by researchers to establish partnerships with farmers that could assist with both the research and development of new farming techniques and the adoption of successful systems by other farmers.     

Effects of dimethoate on honey bee foraging

Collection by honey bees of sucrose solutions treated with dimethoate continued uninterrupted until 2.9–3.9 μg/bee had been accumulated. This self-limiting dose was 20–25 times the oral LD₅₀ for honey bees. Therefore a mean of 45 collection trips involving 1 ppm dimethoate or 11 trips involving 5 ppm was possible before foraging ceased. Losses in pollinator effectiveness and adult and larval mortality are likely to result from dimethoate contamination of nectar.     

Bayes methods for combining disease and exposure data in assessing environmental justice

Environmental justice reflects the equitable distribution of the burden of environmental hazards across various sociodemographic groups. The issue is important in environmental regulation, siting of hazardous waste repositories and prioritizing remediation of existing sources of exposure. We propose a statistical framework for assessing environmental justice. The framework includes a quantitative assessment of environmental equity based on the cumulative distribution of exposure within population subgroups linked to disease incidence through a dose-response function. This approach avoids arbitrary binary classifications of individuals solely as 'exposed' or 'unexposed'. We present a Bayesian inferential approach, implemented using Markov chain Monte Carlo methods, that accounts for uncertainty in both exposure and response. We illustrate our method using data on leukaemia deaths and exposure to toxic chemical releases in Allegheny County, Pennsylvania.     

Persistence of Violation and Crash Behavior Over Time

This analysis examines the ability of previous offenses to predict future high-risk offenses, and similarly, the ability of crashes to predict future high-risk crashes, using the complete driver history data (up to 9 years) for a set of young Michigan subjects. As expected, those with previous ticketed offenses or reported crashes are at greater risk for future offenses or crashes; with a previous-year serious offense doubling the odds of serious offenses during the subsequent year, and a previous-year at-fault crash increasing the odds of subsequent-year at-fault crashes by nearly 50%. There is modest evidence that serious offenses and at-fault crashes may better predict subsequent behavior in females and in more experienced drivers. This latter finding is also evidenced by the fact that records of these young drivers are less predictive of subsequent driving history than is true for records of all drivers in general found in other studies. This suggests that, in the early stages of driving, offenses and crashes are, at least in part, attributable to inexperience, and hence, characteristic of all beginning drivers.     

Snowblower injuries in Vermont, 1981–1984

The Vermont Department of Health carried out two studies of snowblower injuries in Vermont during the winters of 1982–1983 and 1983–1984. The first was a case-control study in which we assessed risk factors that predisposed operators to injury during snowblower use. We found 20 persons who had been injured by snowblowers and matched 28 controls to these by neighborhood. In this study, owning a snowblower for 1 year or less and having operated a snowblower for 10 days or less in one's lifetime were significantly associated with injury. The second study was population-based. We estimated that approximately 1.5% of Vermont residents owned snowblowers during the winter of 1982–1983 and that, among snowblower owners, injuries occurred at a rate of 1.3/1,000 person-years of ownership (0.1% chance of injury).     

The new environmentalist

This paper looks at the increasingly complex problems which face physical planners in the urban environment and considers the type of training required in the future for those who have to advise the government of the day on physical planning matters.Using the examples of planning problems which have been experienced in Hong Kong and Saudi Arabia, an analysis shows that they fall into three main categories: (a) physical problems (b) social problems, and (c) visual problems.It is considered that the conventional professionals do not possess the necessary basic training skills to deal with these problems as a whole, nor to discover the hidden opportunities. This is particularily relevant in the context of the growing green debates which are becoming of increasing importance worldwide.As populations grow, the demand from pressure groups for scarce land resources will become more and more intensive. Singapore may face these problems because the government whishes to increase the population from 2^1/2 to four million.In conclusion it is considered that we shall need a new type of environmental planner in the future. This environmentalist should have a basic training in the earth sciences, the social sciences and the visual arts.     

The genesis of GDL

This paper discusses the early research that lead to graduated driver licensing, some of the educational principals on which it is based, obstacles to its acceptance, and some of the early efforts in the U.S. and elsewhere. EARLY RESEARCH: The research underlying the concept of graduated driver licensing was a 1971 North Carolina study that identified the overrepresentation of young drivers in crashes at night and when another young person was the right front passenger. EDUCATIONAL PRINCIPALS: Efforts to reduce the risk to young novice drivers applied what was known about learning. The concepts included distributed learning (i.e., over time) and progressing from simple to complex skills. A PROPOSAL: The proposed graduated licensing system based on learning principals included (a) initial experience under low risk conditions, (b) extended supervised practice, (c) gradual move to more complex conditions, and (d) harsher penalties for deliberate risk-taking. OBSTACLES: There were several most common objections raised against graduated licensing. Raising the licensing age decreased mobility. Some young drivers were "good" drivers. Enforcement is difficult. Fear of parental objections. Parents are not driver educators and some young people do not have an available parent. Administrative costs are too high. ACCEPTANCE: Driver educators were the first to see the benefits of a graduated system in the 1970s and 1980s. Toronto nearly adopted a graduated system in 1976. New Zealand was the first to adopt a graduated licensing system in 1984. Michigan in 1997 was the first state to require parental certification of extended supervised driving practice.     

Identifying Determinants of Nations' Wetland Management Programs Using Structural Equation Modeling: An Exploratory Analysis

Integrated management and policy models suggest that solutions to environmental issues may be linked to the socioeconomic and political characteristics of a nation. In this study, we empirically explore these suggestions by applying them to the wetland management activities of nations. Structural equation modeling was used to evaluate a model of national wetland management effort and one of national wetland protection. Using five predictor variables of social capital, economic capital, environmental and political characteristics, and land-use pressure, the multivariate models were able to explain 60% of the variation in nations' wetland protection efforts based on data from 90 nations, as defined by level of participation in the international wetland convention. Social capital had the largest direct effect on wetland protection efforts, suggesting that increased social development may eventually lead to better wetland protection. In contrast, increasing economic development had a negative linear relationship with wetland protection efforts, suggesting the need for explicit wetland protection programs as nations continue to focus on economic development. Government, environmental characteristics, and land-use pressure also had a positive direct effect on wetland protection, and mediated the effect of social capital on wetland protection. Explicit wetland protection policies, combined with a focus on social development, would lead to better wetland protection at the national level.