Application of encapsulation (pH-sensitive polymer and phosphate buffer macrocapsules): a novel approach to remediation of acidic ground water

Macrocapsules, composed of a pH-sensitive polymer and phosphate buffer, offer a novel remediation alternative for acidic ground waters. To test their potential effectiveness, laboratory experiments were carried out followed by a field trial within a coal pile runoff (CPR) acidic contaminant plume. Results of traditional limestone and macrocapsule treatments were compared in both laboratory and field experiments. Macrocapsules were more effective than limestone as a passive treatment for raising pH in well water from 2.5 to 6 in both laboratory and field experiments. The limestone treatments had limited impact on pH, only increasing pH as high as 3.3, and armoring by iron was evident in the field trial. Aluminum, iron and sulfate concentrations remained relatively constant throughout the experiments, but phosphate increased (0.15-32 mg/L), indicating macrocapsule release. This research confirmed that macrocapsules may be an effective alternative to limestone to treat highly acidic ground water.     

Large particles are responsible for elevated bacterial marker levels in school air upon occupation

Muramic acid (Mur) is found in bacterial peptidoglycan (PG) whereas 3-hydroxy fatty acids (3-OH FAs) are found in Gram-negative bacterial lipopolysaccharide (LPS). Thus Mur and 3-OH FAs serve as markers to assess bacterial levels in indoor air. An initial survey, in a school, demonstrated that the levels of dust, PG and LPS (pmol m(-3)) were each much higher in occupied rooms than in the same rooms when unoccupied. In each instance, the Mur content of dust was increased and the hydroxy fatty acid distribution changed similarly suggesting an alteration in the bacterial population. Here, findings are compared with results from two additional schools. Follow-up aerosol monitoring by particle size was also performed for the first time for all 3 schools. The particle size distribution was shown to be quite different in occupied versus unoccupied schoolrooms. Within individual classrooms, concentrations of airborne particles [greater-than-or-equal]0.8 [micro sign]m in diameter, and CO(2) were correlated. This suggests that the increased levels of larger particles are responsible for elevation of bacterial markers during occupation. Release of culturable and non-culturable bacteria or bacterial aggregates from children (e.g. from flaking skin) might explain this phenomenon.     

The most important but least understood semicolon in environmental literature

This paper examines implications of the first semicolon appearing in paragraph 4321 of the National Environmental Policy Act of 1969 (PL-91-190 U.S.A.) and suggests a broader meaning for the concept of environment.     

Radioactivity in asbestos

²²⁶Ra has been measured in five asbestos group minerals. The activity levels are variable, are consistent with other forms of rock and range from 0.01–0.4 pCi ²²⁶Ra/g. Alpha particles from asbestos fibers immobilized in the lower lung near pleural surfaces and in the upper lung on bronchial surfaces may be implicated in initiating mesothelioma and bronchial carcinoma.     

Mercury Balance on a Large Pulverized Coal-Fired Furnace

This paper presents results of a survey of mercury concentrations in coal, ash, water, fly ash, and flue gas discharges from a 5.5 × 10⁶ Ib/hr steam generator serving a 775 MW (net) turbine-generator set. Representative composite or grab samples were obtained for inlet coal and outlet ash and water. Stack samples were obtained for fly ash and mercury vapor emissions while the unit was operated at 660 MW (net) (85% of full load). Samples were analyzed by anodic stripping voltammetry, plasma emission spectroscopy, and neutron activation analysis to determine mercury concentration entering the furnace in the coal and leaving the furnace in the flue gas, fly ash, bottom and hopper ash, and water. Method inter-comparisons are discussed. A material balance for mercury has been calculated from fuel, ash, and stack gas flow rates. About 90% of the mercury in the coal is released and appears as vapor discharged in the stack gas while 10% remains in the residual ash. For a 700 MW (net) unit, about 5 lb/day of mercury vapor is released to the atmosphere.     

Towards a framework to assess,compare and develop monitoring and evaluation of climate change adaptation in Europe

Adaptation is increasingly recognised as essential when dealing with the adverse impacts of climate change on societies, economies and the environment. However, there is insufficient information about the effectiveness of adaption policies, measures and actions. For this reason, the establishment of monitoring programmes is considered to be necessary. Such programmes can contribute to knowledge, learning and data to support adaptation governance. In the European Union (EU), member states are encouraged to develop National Adaptation Strategies (NASs). The NASs developed so far vary widely because of differing views, approaches and policies. A number of member states have progressed to monitoring and evaluating the implementation of their NAS. It is possible to identify key elements in these monitoring programmes that can inform the wider policy learning process. In this paper, four generic building blocks for creating a monitoring and evaluation programme are proposed: (1) definition of the system of interest, (2) selection of a set of indicators, (3) identification of the organisations responsible for monitoring and (4) definition of monitoring and evaluation procedures. The monitoring programmes for NAS in three member states—Finland, the UK and Germany—were analysed to show how these elements have been used in practice, taking into account their specific contexts. It is asserted that the provision of a common framework incorporating these elements will help other member states and organisations within them in setting up and improving their adaptation monitoring programmes.     

A Fuel-Based Motor Vehicle Emission Inventory

Abstract

A fuel-based methodology for calculating motor vehicle emission inventories is presented. In the fuel-based method, emission factors are normalized to fuel consumption and expressed as grams of pollutant emitted per gallon of gasoline burned. Fleet-average emission factors are calculated from the measured on-road emissions of a large, random sample of vehicles. Gasoline use is known at the state level from sales tax data, and may be disaggregated to individual air basins. A fuel-based motor vehicle CO inventory was calculated for the South Coast Air Basin in California for summer 1991. Emission factors were calculated from remote sensing measurements of more than 70,000 in-use vehicles. Stabilized exhaust emissions of CO were estimated to be 4400 tons/day for cars and 1500 tons/day for light-duty and medium- duty trucks, with an estimated uncertainty of ±20% for cars and ±30% for trucks. Total motor vehicle CO emissions, including incremental start emissions and emissions from heavy-duty vehicles were estimated to be 7900 tons/day. Fuelbased inventory estimates were greater than those of California's MVEI 7F model by factors of 2.2 for cars and 2.6 for trucks. A draft version of California's MVEI 7G model, which includes increased contributions from high-emitting vehicles and off-cycle emissions, predicted CO emissions which closely matched the fuel-based inventory. An analysis of CO mass emissions as a function of vehicle age revealed that cars and trucks which were ten or more years old were responsible for 58% of stabilized exhaust CO emissions from all cars and trucks.     

Quality assurance/quality control programs in some U.S. environmental laboratories

The quality control program of the Environmental Measurements Laboratory in radioactivity measurements is described and some results are reported.     

Application of a cave inventory system to stimulate development of management strategies: the case of west-central Florida, USA

The active management of air-filled cave systems is virtually non-existent within the karst landscape of west-central Florida. As in every karst landscape, caves are important because they contain a wide variety of resources (e.g., biota, speleothems) and can act as direct connections between surface and subsurface hydrological processes, potentially exacerbating the pollution of groundwater. Before sound management policies can be drafted, implemented, and enforced, stakeholders must first have knowledge of the management requirements of each cave. However, there is an informational disconnect between researchers, stakeholders, and the recreational caving community. Here, we present a cave inventory system that simplifies the dissemination of resource knowledge to stakeholders so that cave management and protection policies can be drafted and implemented at the state and local level. We inventoried 36 caves in west-central Florida, located on both public and private land, and analyzed cave resource data to provide insights on cave sensitivity and disturbance using two standardized indices. The data revealed that both public and private caves exhibit a wide range of sensitivity and disturbance, and before management strategies can be drafted, the ownership of each cave must be considered. Our inventory geodatabase serves as a link between researchers, landowners, and the public. To ensure the conservation and protection of caves, support from county or state government, combined with cave inventory data, is crucial in developing sound management policy.     

The introduction of Littorina littorea to British Columbia, Canada: potential impacts and the importance of biotic resistance by native predators

Although the establishment and spread of non-indigenous species depends upon survival in the face of novel environmental conditions and novel biological interactions, relatively little attention has been focused on the specific role of native predators in limiting invasion success. The European common periwinkle, Littorina littorea, was recently introduced to the Pacific coast of Canada and provides a case study of an introduction into an area with an important predator guild (sea stars) that is functionally minor in the invader’s native habitat. Here, we assess the likelihood of establishment, spread, and negative ecological impact of this introduced gastropod, with an emphasis on the role of native sea stars as agents of biotic resistance. Size frequency distributions and local market availability suggest that L. littorea was most likely introduced via the live seafood trade. Non-native hitchhikers (e.g., the trematode Cryptocotyle lingua) were found on/in both market and field specimens. Laboratory studies and field observations confirmed that L. littorea can survive seasonal low salinity in Vancouver, British Columbia. Periwinkles also readily consumed native Ulva, suggesting that periwinkles could impact native communities via herbivory or resource competition. Unlike native gastropods, however, L. littorea lacked behavioural avoidance responses to Northeast Pacific predatory sea stars (Pisaster ochraceus and Pycnopodia helianthoides), and sea star predation rates on L. littorea were much higher than predation rates on native turban snails (Chlorostoma funebralis) in common garden experiments. We therefore expect periwinkle establishment in British Columbia to be limited to areas with low predator density, as is seen in its field distribution to date. We caution that this conclusion may understate the importance of the L. littorea introduction if it also serves as a vector for additional non-indigenous species such as C. lingua.