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States that the United States Environmental Protection Agency (EPA) has set effluent limits of dioxin based on the pulp processing technology in issuing rules to control the pulp and paper industry's combined air and water discharges. Details on the final rule; Comments from the EPA; Information on the amount pulp the United States pulp industry produces.

Some 1,976 sites at closed military bases in the United States are contaminated with unexploded ordnance (UXO) left over from live-fire weapons training. These sites present risks to civilians who might come into contact with the UXO and cause it to explode. This paper presents the first systems analysis model for assessing the explosion risks of UXO at former military training ranges. We develop a stochastic model for estimating the probability of exposure to and explosion of UXO, before and after site cleanup. An application of the model to a 310-acre parcel at Fort Ord, California, shows that substantial risk can remain even after a site is declared clean. We estimate that risk to individual construction workers of encountering UXO that explodes would range from 4 × 10-4 to 5 × 10-2, depending on model assumptions, well above typical Occupational Safety and Health Administration (OSHA) and U.S. Environmental Protection Agency (EPA) target risk levels of 10-4 to 10-6. In contrast, a qualitative UXO risk assessment method, the Munitions and Explosives of Concern Hazard Assessment (MEC HA), developed by an interagency work group led by the EPA, indicates that the explosion risk at the case study site is low and "compatible with current and determined or reasonably anticipated future risk." We argue that a quantitative approach, like that illustrated in this paper, is necessary to provide a more complete picture of risks and the opportunities for risk reduction. [ABSTRACT FROM AUTHOR]

Methane emissions from municipal landfills represent 3% of the total United States greenhouse gas emissions that contribute to climate change. These methane emissions can be released to the air or collected and flared. This landfill gas also has the potential to be used to generate electricity. In 1994, the Environmental Protection Agency (EPA) created the Landfill Methane Outreach Program, with the objective of promoting the development of landfill-gas- to-energy projects around the country. There are currently 2,300 active landfills in the United States. Although there are already 382 operational projects, there are many more landfills with the potential to use the gas. EPA has identified at least 630 candidate landfills for energy projects, and many more have still not been identified. The objective of this paper is to evaluate total private and social benefits of landfill-gas-to-energy projects, taking into consideration not only the costs of installing and maintaining the necessary equipment and the revenues obtained from selling the electricity but also a valuation of the greenhouse gas emissions that would be prevented and the emissions of criteria pollutants created by the electricity generating equipment. It also evaluates the break-even government subsidies that would be required to make such projects economically viable from private and social perspectives in comparison to current subsidies. it was found that the private breakeven price of electricity for these projects is lower than $0.04/kWh. Moreover, the optimum social subsidy was found to be less than $0.0085/ kWh, which is about 40% lower than the currently available federal tax break of $0.015/kWh. The method developed for this paper can be applied to other renewable energy technologies, to show their relative social costs and benefits. [ABSTRACT FROM AUTHOR]

The need to use resources efficiently and reduce environmental impacts of industrial products and processes is becoming increasingly important in engineering design; therefore, green engineering principles are gaining prominence within engineering education. This paper describes a general framework for incorporating green engineering design principles into engineering curricula, with specific examples for chemical engineering. The framework for teaching green engineering discussed in this paper mirrors the 12 Principles of Green Engineering proposed byAnastas and Zimmerman (Environ. Sci. Technol 2003, 37, 94A-101A), especially in methods for estimating the hazardous nature of chemicals, strategies for pollution prevention, and approaches leading to efficient energy and material utilization. The key elements in green engineering education, which enlarge the "box" for engineering design, are environmental literacy, environmentally conscious design, and beyond-the-plant boundary considerations. [ABSTRACT FROM AUTHOR]

The article discusses a report within the issue by researcher John Washington and colleagues of the U.S. Environmental Protection Agency (EPA) regarding the degradation time of perfluoropolymers. Fluorotelomer polymers are used in stain repellents and paper coatings and are a significant source of environmental perfluorooctanoic acid (PFOA). PFOA remains in the blood on individuals and the environment for years longer than previously thought. An overview of the study is presented.

The migration of chlorinated volatile organic compounds from groundwater to indoor air–known as vapor intrusion–can be an important exposure pathway at hazardous waste sites. Because sampling indoor air at every potentially affected home is often logistically infeasible, screening tools are needed to help identify at-risk homes. Currently, the U.S. Environmental Protection Agency (EPA) uses a simple screening approach that employs a generic vapor "attenuation factor," the ratio of the indoor air pollutant concentration to the pollutant concentration in the soil gas directly above the groundwater table. At every potentially affected home above contaminated groundwater, the EPA assumes the vapor attenuation factor is less than 1/1000 - that is, that the indoor air concentration will not exceed 1/1000 times the soil–gas concentration immediately above groundwater. This paper reports on a screening-level model that improves on the EPA approach by considering environmental, contaminant, and household characteristics. The model is based on an analysis of the EPA's vapor intrusion database, which contains almost 2,400 indoor air and corresponding subsurface concentration samples collected in 15 states. We use the site data to develop a multilevel regression model for predicting the vapor attenuation factor. We find that the attenuation factor varies significantly with soil type, depth to groundwater, season, household foundation type, and contaminant molecular weight. The resulting model decreases the rate of false negatives compared to EPA's screening approach. [ABSTRACT FROM AUTHOR]

Emissions of sulfur dioxide (SO2) from the U.S. power sector decreased by 24% in 2009 relative to 2008. The Logarithmic Mean Divisia Index (LMDI) approach was applied to isolate the factors responsible for this decrease. It is concluded that 15% of the decrease can be attributed to the drop in demand for electricity triggered by the economic recession, and 28% can be attributed to switching of fuel from coal to gas responding to the decrease in prices for the latter. The largest factor in the decrease, close to 57%, resulted from an overall decline in emissions per unit of power generated from coal. This is attributed in part to selective idling of older, less efficient coal plants that generally do not incorporate technology for sulfur removal, and in part to continued investments by the power sector in removal equipment in response to the requirements limiting emissions imposed by the U.S. Environmental Protection Agency (U.S. EPA). The paper argues further that imposition of a modest tax on emissions of carbon would have ancillary benefits in terms of emissions of SO2. [ABSTRACT FROM AUTHOR]

The U.S. Environmental Protection Agency's "Four Lab Study" involved participation of researchers from four national Laboratories and Centers of the Office of Research and Development along with collaborators from the water industry and academia. The study evaluated toxicological effects of complex disinfection byproduct (DBP) mixtures,with an emphasis on reproductive and developmental effects that have been associated with DBP exposures in some human epidemiologic studies. This paper describes a new procedure for producing chlorinated drinking water concentrate for animal toxicology experiments, comprehensive identification of >100 DBPs, and quantification of 75 priority and regulated DBPs. In the research reported herein, complex mixtures of DBPs were produced by concentrating a natural source water with reverse osmosis membranes, followed by addition of bromide and treatment with chlorine. By concentrating natural organic matter in the source water first and disinfecting with chlorine afterward, DBPs (including volatiles sod semivolatiles) were formed and maintained in a water matrix suitable for animal studies. DBP levels in the chlorinated concentrate compared well to those from EPA's Information Collection Rule (ICR) and a nationwide study of priority unregulated DBPs when normalized by total organic carbon (TOC). DBPs were relatively stable over the course of the animal studies (125 days) with multiple chlorination events (every 5-14 days), and a significant portion of total organic halogen was accounted for through a comprehensive identification approach. DBPs quantified included regulated DBPs, priority unregulated DBPs, and additional DBPs targeted by the ICR. Many DBPs are reported for the first time, including previously undetected and unreported haloacids and hatoamides. The new concentration procedure not only produced a concentrated drinking water suitable for animal experiments, but also provided a greater TOC concentration factor (136x), enhancing the detection of trace DBPs that are often below detection using conventional approaches. [ABSTRACT FROM AUTHOR]

United States Environmental Protection Agency (USEPA) set opacity standards for visual emissions from industrial sources to protect ambient air quality. USEPA developed Method 9, which is a reference method to describe how plume opacity can be quantified by human observers during daytime conditions. However, it would be beneficial to determine plume opacity with digital still cameras (DSCs) to provide graphical records of the plume and its environment during visual emission evaluation and to be able to determine plume opacity with DSCs during nighttime conditions. Digital optical method (DOM) was developed to quantify plume opacity from photographs that were provided by a DSC during daytime. Past daytime field campaigns have demonstrated that DOM provided opacity readings that met Method 9 certification requirements. In this paper, the principles and methodology of DOM to quantify plume opacity during nighttime are described. Also, results are described from a nighttime-field campaign that occurred at Springfield, IL Opacity readings provided by DOM were compared with the opacity values obtained with the reference in-stack transmissometer of the smoke generator. The average opacity errors were 2.3-3.5% for contrast model of DOM for all levels of plume opacity. The average opacity errors were 2.0-7.6% for the transmission model of DOM for plumes with opacity 0-50%. These results are encouraging and indicate that DOM has the potential to quantify plume opacity during nighttime. [ABSTRACT FROM AUTHOR]

This paper presents a geographic information systems (GIS) methodology for evaluating the environmental justice implications of the Toxics Release Inventory (TRI) Burden Reduction Rule, which was issued by the U.S. Environmental Protection Agency in December 2006 under the authority of the Emergency Planning and Community Right-to-Know Act of 1986. This rule exempts industrial facilities meeting certain higher reporting thresholds from filing detailed reports about the quantities of chemicals used, released, or managed as waste. Our analytical approach examines demographic characteristics within a 1, 3, and 5 km buffer around a georeferenced facility location, applied on a national, regional, and state scale. The distance-based GIS analysis demonstrates that TRI facilities that are eligible for reduced reporting are more likely to be located in proximity to communities with a higher percentage of minority and low-income residents. The differences are more pronounced for percent minority and percent minority under age 5 in comparison to percent in poverty, and the demographic differences are more apparent at increasingly resolved geographic scales. [ABSTRACT FROM AUTHOR]

In this paper, we present findings from a multiyear expert judgment study that comprehensively characterizes uncertainty in estimates of mortality reductions associated with decreases in fine particulate matter (PM2.5) in the U.S. Appropriate characterization of uncertainty is critical because mortality- related benefits represent up to 90% of the monetized benefits reported in the Environmental Protection Agency's (EPA's) analyses of proposed air regulations. Numerous epidemiological and toxicological studies have evaluated the PM2.5—mortality association and investigated issues that may contribute to uncertainty in the concentration—response (C—R) function, such as exposure misclassification and potential confounding from other pollutant exposures. EPA's current uncertainty analysis methods rely largely on standard errors in published studies. However, no one study can capture the full suite of issues that arise in quantifying the C—R relationship. Therefore, EPA has applied state-of-the-art expert judgment elicitation techniques to develop probabilistic uncertainty distributions that reflect the broader array of uncertainties in the C—R relationship. These distributions, elicited from 12 of the world's leading experts on this issue, suggest both potentially larger central estimates of mortality reductions for decreases in long-term PM2.5 exposure in the U.S. and a wider distribution of uncertainty than currently employed in EPA analyses. [ABSTRACT FROM AUTHOR]

This paper compares two previously published methods, an Aroclor estimation method and a mixing model method, that relate Aroclor contamination to congener specific data in environmental samples. The Aroclor estimation method, which is consistent with U.S. EPA Method 8082, uses a limited set of congener specific data to estimate Aroclor contributions to the sample, while the mixing model method uses the full congener data to model sample composition as linear combinations of Aroclors. The performance of these methods are compared, using 181 samples at a variety of trophic levels, in terms of (a) total PCB concentrations, (b) compositional modification levels from original Aroclors, and (c) determination of the Aroclor mixture or mixtures best describing the sample (Aroclor speciation). We find that the two methods agree in all three terms for samples of low trophic level, but disagree for samples of higher tropic levels. Most significantly. the comparison reveals systematic overestimation of total PCB content by the Aroclor estimation method for samples at high trophic levels. The implication is that Aroclor determinations using persistent congeners cannot reliably be used as surrogates for total PCB concentration. The strengths and weaknesses of each method are detailed. [ABSTRACT FROM AUTHOR]

Reports on the Environmental Protection Agency's (EPA) targeting of incinerators for regulatory actions in connection with the agency's findings on the health effects of dioxins. Incinerators as major source of dioxins; Two incinerator types; Proposed standards; Role of chlorine in dioxin production; Emission controls; Recycling option. INSET: What happened to pulp and paper?, by Jeff Johnson..

The managing editor discusses his intentions to highlight articles that relate to the featured content of each issue. The featured content of this issue, metals in the environment, is reflected in a paper by Menzie et al. on a U.S. Environmental Protection Agency (EPA) policy document on metal risk assessment, a paper by Luoma and Presser on selenium in the environment, other papers on technetium and uranium bioreduction, and several papers on mercury in the environment.

The article discusses a paper by researchers at the Environmental Protection Agency entitled "A Graphical Systems Model to Facilitate Hypothesis-Driven Ecotoxicogenomics Research on the Teleost Brain-Pituitary-Gonadal Axis." The paper makes it easier for researchers to analyze the complex nature of fish reproduction.

The authors discuss crisis-oriented decision making conducted by the U.S. Environmental Protection Agency (EPA) to address the BP Deepwater Horizon (DWH) oil spill. Elements of crisis science used in responding to the (DWH) oil spill included use of all existing relevant knowledge, understanding and meeting crisis response needs, and ensuring the best possible data quality. Two papers in the issue on crisis science used by EPA are noted.

The article reports on the debate on whether lead should be removed from the list of six "criteria" air pollutants that are regulated by the U.S. Environmental Protection Agency. The debate began when EPA discussed the possibility of removing lead from the list of air pollutants because ambient lead levels are no longer a problem in most parts of United States. The option, which was widely rejected by environmental groups and Congress members, Representative Henry Waxman and Senator Barbara Boxer, was mentioned in the December 5, 2006 draft agency staff paper developed as part of a review of the criteria standard. EPA was required by the Clean Air Act to review, and if needed, update the six criteria pollutants every 5 years.

Presents news briefs on issues relative to the United States Environmental Protection Agency. Details on dredging planned for the Hudson River in the State of New York due to polychlorinated biphenyls contamination; Contents of the paper issued by the EPA entitled `Water Quality issues Related to Coal Mining'; Findings of the EPA report entitled `An Ecological Assessment of the United States Mid-Atlantic Region.'