The Impact of the Hyperacid Ijen Crater Lake. Part II: A Total Diet Study

In Asembagus (East Java, Indonesia), surface water is contaminated with effluent from the hyperacid Ijen Crater Lake. In a previous study, we reported that food crops irrigated with this water had increased concentrations of various elements. Here, we present a total diet study for adults and 6-year-old children to determine if the mean daily intake of a broad range of elements is safe and adequate. For children, the intake of B, Mg, Mn and V is high with Hazard Quotients (HQ) of 1.1 (B), 1.4 (Mn) and 1.4 (V), respectively (no TDI is available for Mg). For Mn, the daily intake is high due to the consumption of locally produced rice. Drinking water is the main source of B, Mg and V. For adults, the intake of Mg, Mn and V is also high but HQ values are ≤0.7. For both children and adults, the intake of Ca, Zn and particularly Fe is below the RNI (Fe intake is 90% below the RNI for women). It is concluded the mean intake of elements is unbalanced and Fe deficiency is probably the most serious health problem. Toxic effects cannot be fully excluded since deficiency of essential elements such as Ca, Fe and Zn can increase the absorption and retention of various elements.     

Disaggregation of nation-wide dynamic population exposure estimates in The Netherlands: Applications of activity-based transport models

Traditional exposure studies that link concentrations with population data do not always take into account the temporal and spatial variations in both concentrations and population density. In this paper we present an integrated model chain for the determination of nation-wide exposure estimates that incorporates temporally and spatially resolved information about people's location and activities (obtained from an activity-based transport model) and about ambient pollutant concentrations (obtained from a dispersion model). To the best of our knowledge, it is the first time that such an integrated exercise was successfully carried out in a fully operational modus for all models under consideration. The evaluation of population level exposure in The Netherlands to NO₂ at different time-periods, locations, for different subpopulations (gender, socio-economic status) and during different activities (residential, work, transport, shopping) is chosen as a case-study to point out the new features of this methodology. Results demonstrate that, by neglecting people's travel behaviour, total average exposure to NO₂ will be underestimated by 4% and hourly exposure results can be underestimated by more than 30%. A more detailed exposure analysis reveals the intra-day variations in exposure estimates and the presence of large exposure differences between different activities (traffic > work > shopping > home) and between subpopulations (men > women, low socio-economic class > high socio-economic class). This kind of exposure analysis, disaggregated by activities or by subpopulations, per time of day, provides useful insight and information for scientific and policy purposes. It demonstrates that policy measures, aimed at reducing the overall (average) exposure concentration of the population may impact in a different way depending on the time of day or the subgroup considered. From a scientific point of view, this new approach can be used to reduce exposure misclassification.     

Foreword

We provide an introduction to the volume The Arctic in the Earth System perspective: the role of tipping points. The terms tipping point and tipping element are described and their role in current science, general debates, and the Arctic are elucidated. From a wider perspective, the volume focuses upon the role of humans in the Arctic component of the Earth system and in particular the envelope for human existence, the Arctic ecosystems. The Arctic climate tipping elements, the tipping elements in Arctic ecosystems and societies, and the challenges of governance and anticipation are illuminated through short summaries of eight publications that derive from the Arctic Frontiers conference in 2011 and the EU FP7 project Arctic Tipping Points. Then some ideas based upon resilience thinking are developed to show how wise system management could ease pressures on Arctic systems in order to keep them away from tipping points.     

Suicides and other fatalities from train-person collisions on Swedish railroads: a descriptive epidemiologic analysis as a basis for systems-oriented prevention

PROBLEM: Suicide is a dominating, although hidden, safety problem on Swedish railroads. The aim of this paper is to describe the epidemiology of fatal train-person collisions as a basis for systems-oriented prevention. METHOD: Data on collision circumstances were collected from narrative reports at the Swedish National Rail Administration. RESULTS: The events were evenly distributed by months and weekdays, however, most suicides occur during the day while unintentional events usually occur at night. Most train-person collisions happened in densely populated areas, and 75% of the suicide victims were waiting on the track before the collision. Significance test between types of injury event (suicide, accident, or unknown intent) showed small or no differences. CONCLUSION: Traditional approaches to accident prevention by systems modification seem largely applicable to combat railroad suicide as well. IMPACT ON INDUSTRY: Our findings show promising preventive potentials.     

Rapid one-step assays for on-site monitoring of mouse and rat urinary allergens

Allergy to rodent proteins is common among laboratory animal workers. Sensitive methods to measure exposure to these allergens have been developed. These assays are, however, expensive, time-consuming, and require a laboratory facility and methodological expertise. A simple method to screen for allergen spread, or to test whether hygiene standards are maintained, would be useful. Lateral flow immunoassays (LFIAs) are especially suited for field settings; the tests are simple and results are visible within minutes. LFIAs were developed for detection of the rodent urinary allergens Mus m 1 and Rat n 1. Pilot studies were performed in animal facilities in three countries using both extracts from airborne dust samples and samples collected by wiping surfaces. For comparison and determination of sensitivity, the concentrations of rodent urinary allergens in the samples were also measured using enzyme immunoassays (EIAs). The LFIAs for rat and mouse urinary allergens had a detection limit of 31 pg allergen per mL in a buffer system with purified allergen standards. Results of environmental dust extracts tested in LFIAs correlated well with levels obtained using EIAs. Spread of rodent allergens, or non-adherence to hygiene around laboratory animal facilities, may aggravate rodent allergy. Using a simple, sensitive one-step assay, allergens can be detected to prevent allergen exposure. The results reveal that the rapid assays are suited for on-site demonstration of exposure to rodent allergens, and thus, useful in occupational hygiene practice.