A novel approach to model 4 decades of marine chemical data

The awareness of the negative effects of chemical pollution in the sixties has led to an increased concern on the chemical status of the marine environment in the following decades. International regulation in Europe started with the Oslo and Paris convention in the seventies, later on leading to the OSPAR commission. At national level, extended research on chemical pollutants in marine sediments and marine biota was done within the “Project Mer/Projekt Zee” from 1970 to 1976. Since then, a long series of research and monitoring projects was conducted, reporting on the chemical status of the Belgian Part of the North&nbsp;Sea. &nbsp; Within the 4demon project, a major work package focused on the collection, quality control and intercalibration of more than 40 years of data on heavy metals and polychlorinated biphenyls. In this presentation, the modelling approach and results on sediment data will be&nbsp;presented. &nbsp; Within current OSPAR and MSFD monitoring on chemical pollution, variability in location, seasonality, grain size, etc. is reduced thanks to standardized OSPAR guidelines. This facilitates comparability of data within and between regions and assessments based on 5-15 year timetrends are frequently made. Within more than 40 years of pollution data, variability is much larger, and multiple issues should be tackled to intercalibrate the data: changes in sampling locations and analyses methods over time, missing essential metadata, sample analysis on different grain size fractions,… Therefore, existing time trend modelling approaches could not be applied within the 4Demon project. An alternative approach, focused on cluster analysis and different normalisation procedures was proposed. A parametric linear mixed effect model was used to integrate all data into consistent long term time lines which give a view on PCB and heavy metal pollution on a large time&nbsp;frame. &nbsp; Acknowledgement We want to thank the Belgian Science Policy Office (BELSPO) for the financial support of the 4Demon&nbsp;project.</p

A Mediational Model to Explain the Job Insecurity-Emotional Exhaustion Relationship: Breach of Psychological Contract and Distributive Injustice as Intervening Variables

Empirical evidence considers job insecurity as a stressor that leads to poor job-related well-being. With the present study we intend to increase this knowledge by testing how and through what mechanisms job insecurity may give rise to such consequences. In particular, we examined the mediating processes underlying the relationship between job insecurity and emotional exhaustion, as an indicator of psychological well-being and core element of burnout. A total of 322 blue collar workers in Italy are used to test the hypotheses derived from our framework. The results found support for a model in which the effect of job insecurity on exhaustion was mediated by two variables indicating lack of reciprocity, i.e. breached psychological contract and perceived distributive injustice (partial mediational model). Thus, the effect of job insecurity on burnout could partly be interpreted in terms of inequity perceived from the exchange relationship between employee and organization. The tested model provides a theoretical framework that may lead to new insights on the job insecurity-exhaustion relationship and on the development of burnout in the uncertain organizational context. Results are discussed and theoretical and practical implications are suggested