Regulatory risk control through mandatory occupational safety and health (OSH) certification and testing regimes (CTRs)

Governments make increasing use of private certification and testing infrastructures as an alternative for traditional regulatory arrangements in several areas including occupational safety and health (OSH).This research, commissioned by the Dutch Inspectorate for Work and Income (IWI), concerns an analysis of risk control of four certification and testing regimes (CTRs) in the Netherlands, three mandatory regimes and one non-mandatory regime. The aim was to create a better understanding of problems that may arise in the risk control through such regimes and to identify critical processes and factors that can affect the risk control process.The results of this research are reported in two papers in this special issue (see also Zwetsloot et al., this issue). This one presents an analysis of the risk control at the regulatory level, and its associated critical factors and processes. These critical factors are clustered in four essential processes: the regulatory choice for a CTR, the definition of requirements for the auditing or inspection regime, the certification and testing processes as such, and the processes needed for the self-correcting or learning capability of the CTR. Jointly, these factors and processes form a framework for both the design and the evaluation of such regimes. The case studies clearly demonstrate that these critical factors may undermine the effectiveness of such regulatory practices. We propose that a further development of our framework should be used in the (re)design process for proposed and existing CTRs, and in the process of independent evaluation of such regimes.     

Phytotoxicity of nitroaromatic energetic compounds freshly amended or weathered and aged in sandy loam soil

The toxicities of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), and 2,6-dinitrotoluene (2,6-DNT) to terrestrial plants alfalfa (Medicago sativa L.), Japanese millet (Echinochloa crusgalli L.), and perennial ryegrass (Lolium perenne L.) were determined in Sassafras sandy loam soil using seedling emergence, fresh shoot, and dry mass measurement endpoints. A 13-week weathering and aging of energetic materials in soils, which included wetting and drying cycles, and exposure to sunlight of individual soil treatments, was incorporated into the study design to better reflect the soil exposure conditions in the field than toxicity determinations in freshly amended soils. Definitive toxicity tests showed that dinitrotoluenes were more phytotoxic for all plant species in freshly amended treatments based on EC20 values for dry shoot ranging from 3 to 24mgkg(-1) compared with values for TNB or TNT ranging from 43 to 62mgkg(-1). Weathering and aging of energetic materials (EMs) in soil significantly decreased the toxicity of TNT, TNB or 2,6-DNT to Japanese millet or ryegrass based on seedling emergence, but significantly increased the toxicity of all four EMs to all three plant species based on shoot growth. Exposure of the three plant species to relatively low concentrations of the four compounds initially stimulated plant growth before the onset of inhibition at greater concentrations (hormesis).     

Developing a standard for psychosocial risk management: PAS 1010

The nature of work has changed dramatically due to globalisation, migration, technological advances and the emergence of the knowledge-based economy. These changes have been accompanied by the increased prevalence of new and emerging types of risk to workers’ health and safety, such as psychosocial risks. This paper reviews the key regulatory and voluntary standards on occupational health and safety of relevance to the management of psychosocial risks in the workplace that are applicable to the European Union member states. The review indicates that regulatory standards set the minimum level of protection for workers and voluntary standards may further enable organisations to go beyond their legal obligations. However, the review also highlights that the terms ‘stress’ and ‘psychosocial risks’ are not mentioned explicitly in most pieces of legislation leading to lack of clarity on the terminology used. While voluntary standards seek to address this, very few provide specific guidance on the process of psychosocial risk management to enable organisations to manage psychosocial risks successfully. On the basis of the review, the case for the development of a voluntary standard for psychosocial risk management is presented. The paper further discusses the recent development of such a standard and its implications at the European level.     

Coral cavity sponges depend on reef-derived food resources: stable isotope and fatty acid constraints

The diet of cavity sponges on the narrow fringing reefs of Curaçao, Caribbean was studied. The origin and resources of the bulk food of these sponges, i.e., dissolved organic matter (DOM), were identified using stable carbon and nitrogen isotopes and fatty acid biomarkers. We found that phytoplankton and its derived DOM from the adjacent open sea and from reef overlying water is not the main source of food for most of the sponges examined nor is bacterioplankton. Interestingly, dual stable isotope signatures (δ¹³C_org, δ¹⁵N_org) and fatty acid biomarkers appoint coral mucus and organic matter derived from crustose coralline algae (CCA) as probable food sources for encrusting sponges. Mucus-derived DOM may contribute up to 66% to the diet of examined sponges based on results of dual isotope mixing model analysis. The contribution of CCA (as purported representative for benthic algae) was smaller with values up to 31%. Together, mucus- and CCA-derived substrates contributed for 48–73% to the diet of sponges. The presence of the exogenous fatty acid 20:4ω6 in sponges, which is abundant in coral mucus of Madracis mirabilis and in CCA, highlights these reef-derived resources as sources of nutrition for DOM feeding cavity sponges. The relatively high concentrations of exogenous 20:4ω6 in all sponges examined supports our hypothesis that the bulk of the food of the cavity sponge community is reef-derived. Our results imply that cavity sponges play an important role in conserving food and energy produced within the reef.     

Simultaneous-count models to estimate abundance from counts of unmarked individuals with imperfect detection

We developed a method to estimate population abundance from simultaneous counts of unmarked individuals over multiple sites. We considered that at each sampling occasion, individuals in a population could be detected at 1 of the survey sites or remain undetected and used either multinomial or binomial simultaneous-count models to estimate abundance, the latter being equivalent to an N-mixture model with one site. We tested model performance with simulations over a range of detection probabilities, population sizes, growth rates, number of years, sampling occasions, and sites. We then applied our method to 3 critically endangered vulture species in Cambodia to demonstrate the real-world applicability of the model and to provide the first abundance estimates for these species in Cambodia. Our new approach works best when existing methods are expected to perform poorly (i.e., few sites and large variation in abundance among sites) and if individuals may move among sites between sampling occasions. The approach performed better when there were >8 sampling occasions and net probability of detection was high (>0.5). We believe our approach will be useful in particular for simultaneous surveys at aggregation sites, such as roosts. The method complements existing approaches for estimating abundance of unmarked individuals and is the first method designed specifically for simultaneous counts.