Air pollution and mortality rates: A note on Lave and Seskin's pooling of cross-section and time-series data

In “Air Pollution and Human Health” (Johns Hopkins University Press, Baltimore, 1977) Lester Lave and Eugene Seskin report the results of regressions which suggest a strong association between air pollution and mortality rates. This note questions assumptions made by Lave and Seskin which underlie their -estimation of a single-equation model using pooled cross-section and time-series data. If, in fact, these assumptions cannot be made, the association between air pollution and mortality rates appears considerably weakened, but it still appears to be significant.     

Private and Social Costs of Surface Mine Reforestation Performance Criteria

We study the potentially unnecessary costs imposed by strict performance standards for forest restoration of surface coal mines in the Appalachian region under the Surface Mining Control and Reclamation Act of 1977 (SMCRA) that can vary widely across states. Both the unnecessary private costs to the mine operator and costs to society (social costs) are reported for two performance standards, a ground cover requirement, and a seedling survival target. These standards are examined using numerical analyses under a range of site productivity class and market conditions. We show that a strict (90%) ground cover standard may produce an unnecessary private cost of more than 700/ha and a social cost ranging from700/ha and a social cost ranging from 428/ha to 710/ha, as compared with a 70 standard, may produce an unnecessary private cost of approximately710/ha, as compared with a 70% standard. A strict tree survival standard of 1235 trees/ha, as compared with the more typical 1087 trees/ha standard, may produce an unnecessary private cost of approximately 200/ha, and a social cost in the range of 120 to120 to 208/ha. We conclude that strict performance standards may impose substantial unnecessary private costs and social costs, that strict performance standards may be discouraging the choice of forestry as a post-mining land use, and that opportunities exist for reform of reforestation performance standards. Our study provides a basis for evaluating tradeoffs between regulatory efficiency and optimal reforestation effort.     

Mitigation of global greenhouse gas emissions from waste: conclusions and strategies from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. Working Group III (Mitigation).

Greenhouse gas (GHG) emissions from post-consumer waste and wastewater are a small contributor (about 3%) to total global anthropogenic GHG emissions. Emissions for 2004-2005 totalled 1.4 Gt CO2-eq year(-1) relative to total emissions from all sectors of 49 Gt CO2-eq year(-1) [including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and F-gases normalized according to their 100-year global warming potentials (GWP)]. The CH4 from landfills and wastewater collectively accounted for about 90% of waste sector emissions, or about 18% of global anthropogenic methane emissions (which were about 14% of the global total in 2004). Wastewater N2O and CO2 from the incineration of waste containing fossil carbon (plastics; synthetic textiles) are minor sources. Due to the wide range of mature technologies that can mitigate GHG emissions from waste and provide public health, environmental protection, and sustainable development co-benefits, existing waste management practices can provide effective mitigation of GHG emissions from this sector. Current mitigation technologies include landfill gas recovery, improved landfill practices, and engineered wastewater management. In addition, significant GHG generation is avoided through controlled composting, state-of-the-art incineration, and expanded sanitation coverage. Reduced waste generation and the exploitation of energy from waste (landfill gas, incineration, anaerobic digester biogas) produce an indirect reduction of GHG emissions through the conservation of raw materials, improved energy and resource efficiency, and fossil fuel avoidance. Flexible strategies and financial incentives can expand waste management options to achieve GHG mitigation goals; local technology decisions are influenced by a variety of factors such as waste quantity and characteristics, cost and financing issues, infrastructure requirements including available land area, collection and transport considerations, and regulatory constraints. Existing studies on mitigation potentials and costs for the waste sector tend to focus on landfill CH4 as the baseline. The commercial recovery of landfill CH4 as a source of renewable energy has been practised at full scale since 1975 and currently exceeds 105 Mt CO2-eq year(-1). Although landfill CH4 emissions from developed countries have been largely stabilized, emissions from developing countries are increasing as more controlled (anaerobic) landfilling practices are implemented; these emissions could be reduced by accelerating the introduction of engineered gas recovery, increasing rates of waste minimization and recycling, and implementing alternative waste management strategies provided they are affordable, effective, and sustainable. Aided by Kyoto mechanisms such as the Clean Development Mechanism (CDM) and Joint Implementation (JI), the total global economic mitigation potential for reducing waste sector emissions in 2030 is estimated to be > 1000 Mt CO2-eq (or 70% of estimated emissions) at costs below 100 US$ t(-1) CO2-eq year(-1). An estimated 20-30% of projected emissions for 2030 can be reduced at negative cost and 30-50% at costs < 20 US$ t(-) CO2-eq year(-1). As landfills produce CH4 for several decades, incineration and composting are complementary mitigation measures to landfill gas recovery in the short- to medium-term--at the present time, there are > 130 Mt waste year(-1) incinerated at more than 600 plants. Current uncertainties with respect to emissions and mitigation potentials could be reduced by more consistent national definitions, coordinated international data collection, standardized data analysis, field validation of models, and consistent application of life-cycle assessment tools inclusive of fossil fuel offsets.     

Thermally enhanced hydrolysis for treatment of pesticides and explosives

Thermally enhanced hydrolysis of halogenated alkanes such as 1,1,1‐trichlorethane has become a proven method of in situ soil and groundwater remediation. Electrical resistance heating is commonly used to heat soil and groundwater to accelerate the rate of hydrolysis. This article provides practical information to extend the hydrolysis remediation toolkit to include treatment of common pesticides and explosives. Sites with comingled volatile compounds, pesticides, and/or explosives can also be treated via a single solution.     

Salmonella survival in manure-treated soils during simulated seasonal temperature exposure

Addition of animal manure to soil can provide opportunity for Salmonella contamination of soil, water, and food. This study examined how exposure of hog manure-treated loamy sand and clay soils to different simulated seasonal temperature sequences influenced the length of Salmonella survival. A six-strain cocktail of Salmonella serovars (Agona, Hadar, Heidelberg, Montevideo, Oranienburg, and Typhimurium) was added to yield 5 log cfu/g directly to about 5 kg of the two soils and moisture adjusted to 60 or 80% of field capacity (FC). Similarly, the Salmonella cocktail was mixed with fresh manure slurry from a hog nursery barn and the latter added to the two soils at 25 g/kg to achieve 5 log cfu/g Salmonella. Manure was mixed either throughout the soil or with the top kilogram of soil and the entire soil volume was adjusted to 60 or 80% FC. Soil treatments were stored 180 d at temperature sequences representing winter to summer (-18, 4, 10, 25 degrees C), spring to summer (4, 10, 25, 30 degrees C), or summer to winter (25, 10, 4, -18 degrees C) seasonal periods with each temperature step lasting 45 d. Samples for Salmonella recovery by direct plating or enrichment were taken at 0, 7, and 15 d post-inoculation and thereafter at 15-d intervals to 180 d. Salmonella numbers decreased during application to soil and the largest decreases occurred within the first week. Higher soil moisture, manure addition, and storage in the clay soil increased Salmonella survival. Salmonella survived longest (> or = 180 d) in both soils during summer-winter exposure but was not isolated after 160 d from loamy sand soil exposed to other seasonal treatments. For all but one treatment decimal reduction time (DRT45d) values calculated from the first 45 d after application were < or = 30 d and suggested that a 30-d delay between field application of manure in the spring or fall and use of the land would provide reasonable assurance that crop and animal contamination by Salmonella would be minimized.     

A spectroscopic study of the bromination of the endocrine disruptor ethynylestradiol

Bromination of ethynylestradiol (EE2) was studied using fluorescence and conventional and stopped-flow absorbance spectroscopy. EE2 transformations in the presence of bromine were determined to proceed through sequential reactions. The first step is very rapid and results in the formation of a brominated cyclohexadienone that is susceptible to reduction but in oxidative conditions it undergoes a transformation into monobromo-EE2 in a first-order OH- -accelerated reaction. The transformation from monobromo-EE2 to dibromo-EE2 follows a similar mechanism. The rates of reactions of bromine-substituted EE2 species are orders of magnitude lower than that of the parent compound indicating that these species can persist in conditions typical for water treatment operations.     

Ozonation effects on emerging micropollutants and effluent organic matter in wastewater: characterization using changes of three-dimensional HP-SEC and EEM fluorescence data

The degradation of effluent organic matter (EfOM) in a municipal wastewater treated by ozonation was characterized using the methods of high-performance size-exclusion chromatography (HP-SEC) and excitation/emission matrix (EEM) fluorescence combined with parallel factor analysis (PARAFAC). The removal of 40 diverse trace-level contaminants of emerging concern (CEC) present in the wastewater was determined as well. Ozonation caused a rapid decrease of the absorbance and fluorescence of the wastewater, which was associated primarily with the oxidation of high and low apparent molecular weight (AMW) EfOM fractions. PARAFAC analysis also showed that components C1 and C2 decreased prominently in these conditions. The EfOM fraction of intermediate molecular weight ascribable to a terrestrial humic-like component (C3) tended to be less reactive toward ozone. Relative changes of EEM fluorescence were quantified using F _max values of PARAFAC-identified components (∆F/F ⁰ _max). Unambiguous relationships between ∆F/F ⁰ _max values and the extent of the degradation of the examined CECs (∆C/C₀) were established. This allowed correlating main parameters of the ∆C/C₀ vs. ∆F/F ⁰ _max relationships with the rates of oxidation of these CECs. The results demonstrate the potential of online measurements of EEM fluorescence for quantitating effects of ozonation on EfOM and micropollutants in wastewater effluents.