Humic acid in ice: Photo-enhanced conversion of nitrogen dioxide into nitrous acid

Laboratory studies on the heterogeneous conversion of nitrogen dioxide into nitrous acid on irradiated ice films containing humic acid are described. It was found that the presence of light in the visible range of the solar spectrum significantly enhances the rate of nitrous acid release from a humic acid doped ice film. This process might contribute to observed HONO production in snow, where the NO₂ is thought to originate from nitrate photolysis. Analysis of the experimental data based on the Langmuir Hinshelwood model framework allowed quantification of the observed dependencies of the nitrous acid production rate on nitrogen dioxide concentration. The observed dependencies on the humic acid concentration as well as on the irradiation intensity were used to estimate light-driven HONO fluxes for environmental snow covers.     

Increasing seat belt use through PI&E and enforcement: The Thumbs Up campaign

Campaigns to increase seat belt use have been effective in controlled environments, in small geographic areas, in primary enforcement states, and when conducted in conjunction with the enactment of seat belt legislation. The Thumbs Up project was undertaken to determine if belt use could be facilitated in less advantageous conditions. A 3-month campaign to increase seat belt use was conducted in two sites, each consisting of two Florida counties. At its conclusion, the Thumbs Up project did not yield an overall increase in seat belt use across the two sites. However, observed seat belt use and the number of seat belt citations issued increased significantly in one site. The results are discussed in terms of the two components necessary for a successful campaign: public information and education, and enforcement. Further, recommendations for conducting successful community-based seat belt interventions are offered.     

ASSESSMENT OF POSSIBLE IMPACTS OF CLIMATE CHANGE IN AN URBAN CATCHMENT1

ABSTRACT: Stationarity of rainfall statistical parameters is a fundamental assumption in hydraulic infrastructure design that may not be valid in an era of changing climate. This study develops a framework for examining the potential impacts of future increases in short duration rainfall intensity on urban infrastructure and natural ecosystems of small watersheds and demonstrates this approach for the Mission/Wagg Creek watershed in British Columbia, Canada. Nonstationarities in rainfall records are first analyzed with linear regression analysis, and the detected trends are extrapolated to build potential future rainfall scenarios. The Storm Water Management Model (SWMM) is used to analyze the effects of increased rainfall intensity on design peak flows and to assess future drainage infrastructure capacity according to the derived scenarios. While the framework provided herein may be modified for cases in which more complex distributions for rainfall intensity are needed and more sophisticated stormwater management models are available, linear regressions and SWMM are commonly used in practice and are applicable for the Mission/Wagg Creek watershed. Potential future impacts on stream health are assessed using methods based on equivalent total impervious area. In terms of impacts on the drainage infrastructure, the results of this study indicate that increases in short duration rainfall intensity may be expected in the future but that they would not create severe impacts in the Mission/Wagg Creek system. The equivalent levels of imperviousness, however, suggest that the impacts on stream health could be far more damaging.     

Potential and Shortcomings of Numerical Weather Prediction Models in Providing Meteorological Data for Urban Air Pollution Forecasting

The last decade progress in numericalweather prediction (NWP) modelling and studies of urbanatmospheric processes for providing meteorological data forurban air pollution forecasting is analysed on examples ofseveral European meteorological centres. Modern nested NWP models are utilising land-use databasesdown to 1 km resolution or finer, and are approaching thenecessary horizontal and vertical resolution suitable forcity scale. The recent scientific developments in the fieldof urban atmospheric physics and the growing availabilityof high-resolution urban surface characteristics datapromise further improvements of the capability of NWPmodels for this aim. A strategy to improve NWP data forthe urban air pollution forecasting is suggested.     

Industrial relations,worksite stress reduction,and employee well-being: A participatory action research investigation

The workplace has become the locus of many stress management and stress reduction interventions. However, little attention has focused on how worksite factors affect the implementation and impact of such interventions. In this paper, we investigate the effect of new versus traditional industrial relations practices on the impact of a worksite stress reduction program in a manufacturing setting. More specifically, a participatory action research (PAR) stress project is described and evaluated in two different labor–management relations contexts. One organization is characterized by the emerging ’new‘ industrial relations system where labor–management relations incorporate elements of joint problem-solving. The other organization has a more traditional approach where labor–management relations are formally adversarial. Results indicate that the labor–management relations context did influence the impact of the stress project. Involvement in the PAR stress project enhanced employee participation in decision-making in both contexts. However, involvement in the stress project enhanced employees' perceptions of the climate for participation only in the organization with more cooperative industrial relations. Increases in coworker support and decreases in depressive symptoms were associated with involvement in the PAR stress project in the organization with more adversarial industrial relations.     

Trisomy 15 mosaicism owing to familial reciprocal translocation t(1;15): implication for prenatal diagnosis

We describe a 4-year-old female child with severe global mental retardation, myoclonic epilepsy, proximal hypotonia and dysmorphisms, whose prenatal diagnosis following amniocentesis revealed a constitutional female karyotype carrying a t(1;15)(q10;p11) familial reciprocal translocation. Post-natal high-resolution karyotype, Fluorescence in situ hybridization (FISH) screening for subtelomeric rearrangements, VNTR search for UPD15 in the blood and fibroblast, and WCP1 and 15 in the mother, failed to provide an explanation for the complex clinical phenotype of the proband. Since the pachytene configuration of the translocated chromosomes defines a high probability of 3:1 segregation, an extensive workup was undertaken to look for a possibly cryptic mosaicism. Four percent of the cells with trisomy 15 was found in the peripheral blood lymphocytes examined by classical cytogenetic technique and interphase FISH analysis. The clinical features associated with cryptic trisomy 15 mosaicism and the problems concerning prenatal diagnosis and genetic counselling for carriers of translocations at high risk of 3:1 segregation are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Existing oxidant/ozone standards in OECD countries

This paper describes the historical development and current legislation to control photochemical oxidant pollution in OECD countries. Policies for implementing, attaining, and maintaining ambient air quality standards or goals are discussed, problems associated with the various steps are highlighted, and the possibility of international policy guidelines which could control pollution across national frontiers is considered. To date, only a few countries have formulated ambient air quality standards for ozone/ oxidants; these standards are usually short-term averages over 1 h, ranging from 0.06 ppm (μL/L) in Japan to 0.12 ppm (μL/L) in the United States. The current interest in air quality management on an international scale leads to the conclusion that successful control of photochemical oxidant pollution would be best accomplished through the establishment of internationally acceptable standards or goals for oxidants/ozone based on health effects and other relevant environmental impacts, in combination with control strategies developed and implemented on an international level.     

Roles of land use resolution and unit-area load rates in assessment of diffuse nutrient emissions

In contrast to its counterparts in Europe and North America, the Australian National Pollutant Inventory (NPI) includes estimates of aggregated emissions of nutrients (total nitrogen and total phosphorus) from catchments and facilities. Sparse or inadequate data limit the extent to which nutrient exports may be estimated from direct observations. The paucity of data for calibration and simulation limits the use of sophisticated models in most Australian catchments. Therefore, a simple unit-area load model-Catchment Management Support System (CMSS)-was selected to estimate aggregated catchment emissions for the NPI. Estimates from models like CMSS are sensitive to spatial and categorical resolution of land uses identified within the catchment and to nutrient generation rates selected for each land use category. Using three Hawkesbury-Nepean subcatchments, we show that while high spatial resolution of land use mapping is useful, only four or five major land use categories with carefully selected generation rates were required to estimate potential nutrient exports sufficiently well and to determine subcatchments contributing most. Nutrient emission estimates proved to be highly dependent on selection of generation rates so a bootstrap technique was adopted to reduce subjectivity and to improve estimates of confidence limits. This led to a specification of new generation rates for Natural, Unimproved pasture, Rural and Urban land uses and to establishment of uncertainty limits.     

New international long-term ecological research on air pollution effects on the Carpathian Mountain forests,Central Europe

An international cooperative project on distribution of ozone in the Carpathian Mountains, Central Europe was conducted from 1997 to 1999. Results of that project indicated that in large parts of the Carpathian Mountains, concentrations of ozone were elevated and potentially phytotoxic to forest vegetation. That study led to the establishment of new long-term studies on ecological changes in forests and other ecosystems caused by air pollution in the Retezat Mountains, Southern Carpathians, Romania and in the Tatra Mountains, Western Carpathians on the Polish-Slovak border. Both of these important mountain ranges have the status of national parks and are Man & the Biosphere Reserves. In the Retezat Mountains, the primary research objective was to evaluate how air pollution may affect forest health and biodiversity. The main research objective in the Tatra Mountains was to evaluate responses of natural and managed Norway spruce forests to air pollution and other stresses. Ambient concentrations of ozone (O(3)), sulfur dioxide (SO(2)), nitrogen oxides (NO(x)) as well as forest health and biodiversity changes were monitored on densely distributed research sites. Initial monitoring of pollutants indicated low levels of O(3), SO(2), and NO(x) in the Retezat Mountains, while elevated levels of O(3) and high deposition of atmospheric sulfur (S) and nitrogen (N) have characterized the Tatra Mountains. In the Retezat Mountains, air pollution seems to have little effect on forest health; however, there was concern that over a long time, even low levels of pollution may affect biodiversity of this important ecosystem. In contrast, severe decline of Norway spruce has been observed in the Tatra Mountains. Although bark beetle seems to be the immediate cause of that decline, long-term elevated levels of atmospheric N and S depositions and elevated O(3) could predispose trees to insect attacks and other stresses. European and US scientists studied pollution deposition, soil and plant chemistry, O(3)-sensitive plant species, forest insects, and genetic changes in the Retezat and Tatra Mountains. Results of these investigations are presented in a GIS format to allow for a better understanding of the changes and the recommendations for effective management in these two areas.