Review of information on pesticide residues in the Canadian environment

Summary Pesticide residues in soil, water, food, wildlife and other media have been analysed in several monitoring studies. The purpose was to establish the distribution of these residues across a defined area, ascertain their trend over a specific period and use the results to assess environmental compliance and safety. In the present review the availability of information on pesticide residues in various Canadian environmental components was sought. With the possible exception of localized pesticide contamination of some private water supply wells, ground and surface water, most analyses revealed concentrations below guideline limits. Only a few cases were reported of mishandling, misuse and poisoning from pesticides. Continuing surveillance programmes and in-depth and well-organized monitoring studies, with special focus on areas that are vulnerable to contamination, by both provincial and federal governments, are largely responsible for the encouraging results. This experience in the control of pesticide use and monitoring of residues in the environment should be of particular interest in developing countries.Dr A.Y. Sangodoyin is a senior lecturer in the Department of Agricultural Engineering at the University of Ibadan. He was recently involved in a study visit to the University of Alberta, Edmonton, Alberta, Canada T6G 2G7, where his co-author Dr D.W. Smith is a member of staff in the Department of Civil-Engineering.     

Pressures,trends, and impacts in coastal zones: Interactions between socioeconomic and natural systems

This paper assesses the status of coastal zones in the context of expected climate change and its related impacts, as well as current and future socioeconomic pressures and impacts. It is argued that external stresses and shocks relating to sea-level rise and other changes will tend to exacerbate existing environmental pressures and damage in coastal zones. Coastal zones are under increasing stress because of an interrelated set of planning failures including information, economic market, and policy intervention failures. Moves towards integrated coastal zone management are urgently required to guide the coevolution of natural and human systems. Overtly technocentric claims that assessments of vulnerability undertaken to date are overestimates of likely future damages from global warming are premature. While it is the case that forecasts of sea-level rise have been scaled down, much uncertainty remains over, for example, combined storm, sea surge, and other events. In any case, within the socioeconomic analyses of the problem, resource valuations have been at best only partial and have failed to incorporate sensitivity analysis in terms of the discount rates utilized. This would indicate an underestimation of potential damage costs. Overall, a precautionary approach is justified based on the need to act ahead of adequate information acquisition, economically efficient resource pricing and proactive coastal planning.     

PESTICIDES IN GROUND WATER: DO ATRAZINE METABOLITES MATTER?1

ABSTRACT: Atrazine and atrazine-residue (atrazine + two metabolites - deethylatrazine and deisopropylatrazine) concentrations were examined to determine if consideration of these atrazine metabolites substantially adds to our understanding of the distribution of this pesticide in groundwater of the midcontinental United States. The mean of atrazine.residue concentrations was 53 percent greater than that of atrazine alone for those observations above the detection limit (> 0.05 μg/l). Furthermore, a censored regression analysis using atrazine-residue concentrations revealed significant factors not identified when only atrazine concentrations were used. Thus, knowledge of concentrations of these atrazine metabolites is required to obtain a true estimation of risk of using these aquifers as sources for drinking water, and such knowledge also provides information that ultimately may be important for future management policies designed to reduce atrazine concentrations in ground water.     

Prevention of musculoskeletal complaints in nursing: Aims, approach and content of an ergonomic-educational programme

In 1992 a comprehensive health-promotion project was initiated in seven nursing-homes in the Netherlands. This project was designed to implement an ergonomic-educational programme, with the intention of reducing physical workload and to bring about safe working in order to prevent work-related musculoskeletal complaints. After a period of external support, employees of the nursing-homes should be able to proceed with the programme independently. In this paper the content of the programme and its underlying strategies and theories are described. So far, the programme has got off to a good start in all the nursing-homes. Positive effects of the programme could be demonstrated and guidelines and protocols for safe working were introduced. However, it is as yet too early for definitive conclusions to be drawn regarding the aspect of continuity.     

Getting the ‘pulse’ of your employees: the use of cardiovascular research in better understanding behavior in organizations

Cardiovascular disease has severe consequences for both individual betterment and organizational health. Yet, organization‐based cardiovascular research remains quite limited. This commentary addresses this void by integrating research dating from the famous Hawthorne experiments with current medical science. It then suggests future organizational research on cardiovascular health and recommends use of specific composite cardiovascular measures to advance our understanding of the organizational implications of cardiovascular disease. Copyright © 2006 John Wiley & Sons, Ltd.     

Decoupling task and relationship conflict: the role of intragroup emotional processing

The present paper focuses on the role of emotion in intragroup conflict processes. We propose that how group members handle emotion affects intragroup interactions and has implications for task and relationship conflict. Three types of variables—collective emotional intelligence, intragroup relational ties, and conflict‐relevant interactional norms—constrain negative emotionality and may determine whether task conflict results in damaging relationship conflict. The moderating influence of these variables is discussed, as are compositional issues associated with measuring them. Copyright © 2004 John Wiley & Sons, Ltd.     

Correlating the spatial distribution of atmospheric ammonia with δ15n values at an ammonia release site

A field ammonia (NH₃) release experiment and open top chambers containing moorland monoliths continuously fumigated with NH₃ or sprayed with NH₄Cl were used to assess the potential for using δ¹⁵N values in determining the area of influence around a point NH₃ emission source. δ¹⁵N values are being increasingly used as environmental tracers and we tested the hypothesis that the δ¹⁵N signal from an NH₃ emission source is observable in nearby vegetation. Using modified monitoring devices, atmospheric NH₃ concentrations were found to decrease with distance from source, with δ¹⁵N values also reflecting this trend, producing a signal shift with changing concentration. Open top chamber studies of δ¹⁵N values of Calluna vulgaris (L.) Hull indicated a correlation with deposition treatments in current year shoots. Analysis of Calluna shoots from the NH₃ release showed a similar trend of δ¹⁵N enrichment. Significant linear correlations between δ¹⁵N and percent N in plant material were found, both in the controlled conditions of the open top chambers and at the NH₃ release site, illustrating the possible use of this technique in N deposition biomonitoring.     

Linking field experiments to long-term simulation of impacts of nitrogen deposition on heathlands and moorlands

The results from three long-term field manipulation studies of the impacts of increased nitrogen deposition (0–120 kg N ha^?1 yr^?1) on lowland and upland heathlands in the UK were compared, to test if common responses are observed. Consistent increases in Calluna foliar N content and decreases in litter C:N ratios were found across all sites, while increases in N leaching were not observed at any site over the range 0–80 kg ha^?1 yr^?1. However, the response of Calluna biomass did vary between sites, possibly reflecting site differences in nutrient status and management histories. Five versions of a simulation model of heathland responses to N were developed, each reflecting different assumptions about the fate and turnover of soil N. Model outputs supported the deduction from mass balance calculations at two of the field sites that N additions have resulted in an increase in immobilisation; the latter was needed to prevent the model overestimating measured N leaching. However, this version of the model significantly underestimated Calluna biomass. Model versions, which included uptake of organic N by Callunaand re-mobilisation of N from the soil organic store provided some improvement in the fit between modelled and field biomass data, but re-mobilisation also led to an overestimation of N leaching. Quantification of these processes and their response to increased N deposition are therefore critical to interpreting experimental data and predicting the long-term impacts of atmospheric deposition on heathlands and moorlands.     

Detecting the signal of atmospheric N deposition in recent national-scale vegetation change across Britain

Model estimates of NO_y and NH_x deposition across Britain for 1996 (5 km square resolution) were applied as explanatory variables to account for national-scale, fine-grained changes in plant species composition between 1990 and 1998. Plant species data were recorded from up to 27 fixed plots located within a stratified random sample of 596 1 km². The response variable was a cover-weighted Ellenberg fertility score for each plot. Analyses were carried out separately for woodlands, semi-natural grasslands and heaths/bogs. Most of the variation in the botanical response variable occurred between plots within squares and so could not be explained by the model deposition data. NH_x deposition estimates accounted for significant, but small components of between 1 km² variation in the change in Ellenberg score in grasslands (5.6%) and heath/bogs (9.8%) but not woodlands. NO_y deposition estimates were not significantly associated with vegetation change. Linear models provided the best fit and the slope of the relationship was lower for heath/bogs than grasslands. Further signal attribution at sub-kilometre square scales requires the development of fine-grained models of N deposition that can be generalised across regional sampling domains.