An Empirical Model to Predict Styrene Emissions from Fiber-Reinforced Plastics Fabrication Processes

ABSTRACT

Styrene is a designated hazardous air pollutant, per the 1990 Clean Air Act Amendments. It is also a tropospheric ozone precursor. Fiber-reinforced plastics (FRP) fabrication is the primary source of anthropogenic styrene emissions in the United States. This paper describes an empirical model designed to predict styrene emission factors for selected FRP fabrication processes. The model highlights 10 relevant parameters impacting styrene emission factors for FRP processes, and helps identify future areas of FRP pollution prevention (P2) research. In most cases, the number of these parameters with greatest impact on styrene emission factors can be limited to four or five. Seven different emission studies were evaluated and used as model inputs.     

Air Emission Inventories in North America: A Critical Assessment

Abstract

Although emission inventories are the foundation of air quality management and have supported substantial improvements in North American air quality, they have a number of shortcomings that can potentially lead to ineffective air quality management strategies. Major reductions in the largest emissions sources have made accurate inventories of previously minor sources much more important to the understanding and improvement of local air quality. Changes in manufacturing processes, industry types, vehicle technologies, and metropolitan infrastructure are occurring at an increasingly rapid pace, emphasizing the importance of inventories that reflect current conditions. New technologies for measuring source emissions and ambient pollutant concentrations, both at the point of emissions and from remote platforms, are providing novel approaches to collecting data for inventory developers. Advances in information technologies are allowing data to be shared more quickly, more easily, and processed and compared in novel ways that can speed the development of emission inventories. Approaches to improving quantitative measures of inventory uncertainty allow air quality management decisions to take into account the uncertainties associated with emissions estimates, providing more accurate projections of how well alternative strategies may work. This paper discusses applications of these technologies and techniques to improve the accuracy, timeliness, and completeness of emission inventories across North America and outlines a series of eight recommendations aimed at inventory developers and air quality management decision-makers to improve emission inventories and enable them to support effective air quality management decisions for the foreseeable future.     

Extending the Kolmogorov–Zurbenko Filter: Application to Ozone,Particulate Matter,and Meteorological Trends

Abstract

Tropospheric ozone (O₃) and particulate matter (PM) are pollutants of great concern to air quality managers. Federal standards for these pollutants have been promulgated in recent years because of the known adverse effects of the pollutants on human health, the environment, and visibility. Local meteorological conditions exert a strong influence over day‐to‐day variations in pollutant concentrations; therefore, the meteorological signal must be removed in order for air quality planners and managers to examine underlying emissions-related trends and make better air quality management decisions for the future. Although the Kolmogorov–Zurbenko (KZ) filter has been widely used for this type of trend separation in O₃ studies in the eastern United States, this article aims to extend the method in three key ways. First, whereas the KZ filter is known as a useful tool for O₃ analysis, this study also evaluates its effectiveness when applied to PM. Second, the method was applied to Tucson, AZ, a city in the semi‐arid southwestern United States (Southwest), to evaluate the appropriateness of the method in a region with weaker synoptic weather controls on air quality than the eastern United States. Third, additional forms of output were developed and tailored to be more applicable to decision-makers’ needs through a partnership between academic researchers and air quality planners and managers. Results of the study indicate that the KZ filter is a useful method for examining emissions‐related PM trends, resulting in small, but potentially significant, differences after adjustment. For the Tucson situation with weaker synoptic controls, the KZ method identified mixing height as a more important variable than has been found in other cities.     

Partitioning Gas Tracer Tests for Measurement of Water in Municipal Solid Waste

Abstract

A key component in the operation of almost all bioreactor landfills is the addition of water to maintain optimal moisture conditions. To determine how much water is needed and where to add it, in situ methods are required to measure water within solid waste. Existing technologies often result in measurements of unknown accuracy, because of the variability of solid waste materials and time-dependent changes in packing density, both of which influence most measurement methods. To overcome these problems, a new technology recently developed by hydrologists for measuring water in the vadose zone—the partitioning gas tracer test—was tested. In this technology, the transport behavior of two gas tracers within solid waste is used to measure the fraction of the void space filled with water. One tracer is conservative and does not react with solids or liquids, while a second tracer partitions into the water and is separated from the conservative tracer during transport. This technology was tested in four different solid waste packings and was capable of determining the volumetric water content to within 48% of actual values, with most measurement errors less than 15%. This technology and the factors that affect its applicability to landfills are discussed in this paper.     

Visual analysis to support regulators in electronic order book markets

Electronic markets and automated trading have resulted in a drastic increase in the quantity and complexity of regulatory data. Reconstructing the limit order book and analyzing order flow is an emerging challenge for financial regulators. New order types, intra-market behavior, and other exchange functionality further complicate the task of understanding market behavior at multiple levels. Data visualizations have proven to be a fundamental tool for building intuition and enabling exploratory data analysis in many fields. In this paper, we propose the incorporation of visualizations in the workflow of multiple financial regulatory roles, including market surveillance, enforcement and supporting academic research.     

Climatic, socio-economic, and health factors affecting human vulnerability to cholera in the Lake Victoria basin, East Africa

Cholera epidemics have a recorded history in the eastern Africa region dating to 1836. Cholera is now endemic in the Lake Victoria basin, a region with one of the poorest and fastest growing populations in the world. Analyses of precipitation, temperatures, and hydrological characteristics of selected stations in the Lake Victoria basin show that cholera epidemics are closely associated with El Ni?o years. Similarly, sustained temperatures high above normal (T(max)) in two consecutive seasons, followed by a slight cooling in the second season, trigger an outbreak of a cholera epidemic. The health and socioeconomic systems that the lake basin communities rely upon are not robust enough to cope with cholera outbreaks, thus rendering them vulnerable to the impact of climate variability and change. Collectively, this report argues that communities living around the Lake Victoria basin are vulnerable to climate-induced cholera that is aggravated by the low socioeconomic status and lack of an adequate health care system. In assessing the communities' adaptive capacity, the report concludes that persistent levels of poverty have made these communities vulnerable to cholera epidemics.     

A study of metal and metalloid contaminant availability in Antarctic marine sediments

Previous studies of impacted sites near Casey Station, Antarctica, have revealed elevated concentrations of metals and metalloids, particularly Cd, Cu, Fe, Pb, Sn and Zn in marine sediments. However, attempts to understand the availability and mobility of contaminant elements have not provided a true understanding of speciation. The current work shows, for the first time, that sediments in Brown Bay, an embayment adjacent to the Thala Valley waste disposal site, have elevated concentrations of sulfide, well in excess of that required to bind contaminant metals such as Cd, Cu, Pb and Zn. Furthermore, sediment characterisation using the BCR sequential extraction scheme has shown metal partitioning consistent with sulfides being the controlling factor in metal availability, thus explaining the low porewater concentrations of these metals. The speciation of Sn in Brown Bay, however, is still unclear with the BCR sequential extraction scheme partitioning Sn predominantly into the residual fraction despite Sn being readily extracted by dilute HCl.     

Transport of ammonium perfluorooctanoate in environmental media near a fluoropolymer manufacturing facility

In order to understand better the pathways for transport of ammonium perfluorooctanoate (APFO) from a point source, a focused investigation of environmental media (water and soil) near a fluoropolymer manufacturing facility (Site) was undertaken. Methods were developed and validated at 2 microg kg(-1) [the limit of quantitation (LOQ)] in soil, and at 50 ng l(-1) in water. Environmental media were sampled from a public water supply well field located north of the Site, across a river. The data suggest that APFO air emissions from the Site are transported to the well field, deposited onto the soil, and then migrate downward with precipitation into the underlying aquifer.