Biodiversity of brackish water amphipods (crustacean) in two estuaries, southeast coast of India

The present study about the gammarid amphipods of Vellar and Uppanar estuaries was performed during two seasons (pre-monsoon and post-monsoon, 2005–2006), respectively, in nine habitats: five in the Vellar estuary and four in the Uppanar estuary. Amphipod samples were collected from sediments, oyster beds, seaweeds, sea grass, and mangroves. A total of 29 species of gammarid amphipods were collected in each area. The surface water temperature ranged from 16°C to 26°C, the salinity from 20 to 32 psu, and the pH between 7.5 and 8.3. Dissolved oxygen ranged from 5.3 to 7.8 ml/l. The maximum abundance of amphipods was observed during the pre-monsoon (July to September) in Vellar mangrove, and it was minimum during the pre-monsoon in Uppanar sea grass. It was found that several physicochemical factors, such as salinity, temperature, dissolved oxygen, pH, and the substrate have a marked effect on the distribution and the relative abundance of amphipods. The ranges of species diversity, richness, dominance, and evenness in the Vellar and Uppanar estuaries were 1.58–4.15, 1.82–5.29, 0–0.11, and 0.96–1, respectively. Using multivariate analyses, in each estuary, it was possible to identify different communities of amphipod species according to their habitats.     

A Strategy for Reduction of Particulate Emissions in the Boston Area

Initial implementation plans provided for particulate reduction largely through the imposition of emission limitations on industrial processes, large steam generators, and solid waste disposal, requiring, in turn, application of control equipment for compliance. In many urban areas, this approach is not adequate to achieve the secondary air quality standards so that a more general strategy must be employed. Such strategy may include restrictions on fuel burning, combustion equipment, maintenance programs, utility steam distribution, etc. The potential abatement achievable through such strategies is described using Boston as a case study. Cost and technical factors associated with each strategy are discussed.     

Solar driven nitrous acid formation on building material surfaces containing titanium dioxide: A concern for air quality in urban areas?

The photoenhanced uptake of nitrogen dioxide (NO₂) to the surface of commercially available self-cleaning window glass has been studied under controlled laboratory conditions. This material is one of an array of modern building products which incorporate titanium dioxide (TiO₂) nanoparticles and are finding increasing use in populated urban areas. Amongst the principal drivers for the use of these materials is that they are thought to facilitate the irreversible removal of pollutants such as NO₂ and organic molecules from the atmosphere and thus act to remediate air quality. While it appears that TiO₂ materials do indeed remove organic molecules from built environments, in this study we show that the photoenhanced uptake of NO₂ to one example material, self-cleaning window glass, is in fact accompanied by the substantial formation (50–70%) of gaseous nitrous acid (HONO). This finding has direct and serious implications for the use of these materials in urban areas. Not only is HONO a harmful respiratory irritant, it is also readily photolysed by solar radiation leading to the formation of hydroxyl radicals (OH) together with the re-release of NO_x as NO. The net effect of subsequent OH initiated chemistry can then be the further degradation of air quality through the formation of secondary pollutants such as ozone and VOC oxidation products. In summary, we suggest that a scientifically conceived technical strategy for air quality remediation based on this technology, while widely perceived as universally beneficial, could in fact have effects precisely opposite to those intended.     

The oldest haplogyne spider (Araneae: Plectreuridae), from the Middle Jurassic of China

New fossil spiders (Arachnida: Araneae) from Middle Jurassic (ca. 165 Ma) strata of Daohugou, Inner Mongolia, China are described as Eoplectreurys gertschi gen. et sp. nov. and referred to the modern haplogyne family Plectreuridae. This small family is restricted to southwestern USA, Mexico, and the adjacent Caribbean area today and hitherto has only a sparse Cenozoic fossil record. The morphology of Eoplectreurys is remarkably similar to modern forms and thus demonstrates great evolutionary conservatism. This new discovery not only extends the fossil record of the family by at least 120 Ma to the Middle Jurassic but also supports the hypothesis of a different distribution of the family in the past than today and subsequent extinction over much of its former range.     

Phototransformation of herbicide metsulfuron methyl

Phototransformation of the herbicide metsulfuron methyl was investigated on glass surface under sunlight and ultraviolet (UV) light and compared with dark condition. The half-lives of metsulfuron methyl under UV light and sunlight were found to be 0.5 and 7.8 days respectively. Rate of phototransformation followed first order kinetics with significant correlation coefficient. The major photoproducts were identified as methyl-2-sulfonyl-amino-benzoate, 2-amino-6-methoxy-4-methyltriazine and saccharin (O-sulfobenzoimide). Various metabolites from this study were identified by high performance liquid chromatography (HPLC). Authentic samples required for HPLC comparison were prepared in laboratory and characterized on the basis of nuclear magnetic resonance (NMR) and infra red (IR) spectral data. These metabolites were also identified from metsulfuron methyl treated wheat field soil.     

Benthic community structure, diversity, and productivity in the shallow Barents Sea bank (Svalbard Bank)

The Barents Sea is among the most productive areas in the world oceans, and its shallow banks exhibit particularly high rates of primary productivity reaching over 300 g C m^?2year^?1. Our study focused on the Svalbard Bank, an important feeding area for fishes and whales. In order to investigate how benthic community structure and benthic secondary production vary across environmental gradients and through time, we sampled across the bank and compared results with a similar study conducted 85 years ago. Considerable variability in community structure and function across bank corresponded with differences in the physical structure of the habitat, including currents, sedimentation regimes and sediment type, and overlying water masses. Despite an intensive scallop fishery and climatic shifts that have taken place since the last survey in the 1920s, benthic community structure was very similar to that from the previous survey, suggesting strong system resilience. Primary and secondary production over shallow banks plays a large role in the Barents Sea and may act as a carbon subsidy to surrounding fish populations, of which many are of commercial importance.     

The relationship between the implementation of a Safety Management System and the attitudes of employees towards unsafe acts in aviation

Airports represent highly complex organisations, incorporating such interdependent operations as airlines, ground transport, flight services, ground services, refueling, maintenance, customer services, catering, administration and security. Airports, and especially International Airports, must ensure that their operations are conducted in a safe and efficient manner, as the consequence of any error or failure during operations has the potential for catastrophic outcomes. The international governing body for air transportation, ICAO, requires that airports must implement a Safety Management System as a means of ensuring safe operations and eliminating or reducing the likelihood of low frequency/high consequence incidents. This research project sought to determine the extent to which the implementation of a Safety Management System (SMS) influenced the attitudes of airport employees toward unsafe acts. The hypothesis tested was that the implementation of an SMS into an airport will result in an improvement in attitudes toward safety. A Safety Culture Survey was utilized to measure these attitudes. Two International Airports were chosen to measure the extent to which the introduction of an SMS at one airport would influence the safety attitude and culture of those employees. Sharjah International Airport, UAE, was used as the experimental group, as it did not have a formal SMS in operation, with another English-speaking International Airport (the Second Airport) being used as a control group, as it already had an SMS in operation. A Safety Culture Survey was used as the pre and post-test measure over a 12-month period to determine the extent of influence of the introduction of the SMS at Sharjah Airport. The results of Phase 1 of the survey (June 2008) were compared against the results of Phase 2 of the survey (June 2009). The average score reported by participants at Sharjah Airport increased significantly from pre-test measure to post-test measure in relation to communication, safety rules, supportive environment, personal risk appreciation, work environment, and involvement. At the same time, the average score for personal priorities decreased significantly from Phases 1 to 2. Results indicate that participants at Sharjah Airport recorded a significant positive shift in attitude to the safety factors covered in the Safety Culture Survey, whilst at the same time responses from the Second Airport showed no such shift in attitude. The Second Airport showed neither decline nor improvement in responses. Whilst some methodological issues were identified, the results were of sufficient strength as to conclude that the outcomes reported support the hypothesis that the introduction of an SMS at Sharjah Airport has effected positive changes not observed at the Second Airport. Recommendations for ongoing research were made to further explore the strength of relationship between SMS and safety attitudes, as well as the relationship between safe attitude and safe behaviour.     

EPA’s LIMB Development and Demonstration Program

This paper describes and discusses key design features of the retrofit of EPA’s Limestone Injection Multistage Burner (LIMB) system to an operating, wall-fired utility boiler at Ohio Edison’s Edgewater Station, based on the preliminary engineering design. It further describes results of pertinent projects in EPA's LIMB program and shows how these results were used as the basis for the design of the system. The full-scale demonstration is expected to prove the effectiveness and cost of the LIMB concept for use on large-scale utility boilers. To date, a preliminary engineering design for the Edgewater unit has been prepared incorporating the technology developed in smaller-scale studies. The schedule calls for system start-up by March 1987. EPA is engaged in a multiyear program to develop an improved control technology for emission of sulfur and nitrogen oxides from the combustion of fossil fuels. The technology involves staged-flow coal burners and injection of a reactive sorbeht into the furnace to reduce emissions. The program includes fundamental studies of reaction chemistry and kinetics, bench and pilot scale experimental studies, a full-scale demonstration, and economic and applicability studies. It is structured to establish a basis for future public sector commercialization, as well as help in understanding the technology’s controlling factors.     

Effect of interior door position on room-to-room differences in residential pollutant concentrations after short-term releases

Residential interior door positions influence the pollutant concentrations that result from short-term indoor sources, such as cigarettes, candles, and incense. To elucidate this influence, we reviewed past studies and conducted new experiments in three residences: a single-story 714 m³ ranch-style house, a 510 m³ two-story split-level house, and a 200 m³ two-story house. During the experiments, we released sulfur hexafluoride or carbon monoxide tracer gas over short periods (≤30 min) and measured concentrations in the source room and at least one other (receptor) room for various interior door opening positions. We found that closing a door between rooms effectively prevented transport of air pollutants, reducing the average concentration in the receptor room relative to the source room by 57–100% over exposure periods of 1–8 h. When intervening doors were partially or fully open, the reduction in average concentrations ranged from 3% to 99%, varying as a function of door opening width and the distance between source and receptor rooms.     

CONFLICTING PERSPECTWES ABOUT DETECTION LIMITS AND ABOUT THE CENSORING OF ENVIRONMENTAL DATA1

ABSTRACT: Current conventions for reporting analytical results from environmental samples brings the objectives of laboratory scientists into conflict with those of environmental scientists. The objective of chemical analyses is to provide estimates of the true composition of samples. Reported results must reflect the analytical uncertainty. Current conventions require left-censoring of those results below the Limit of Detection. The objective of statistical interpretation of environmental data is to provide estimates of the characteristics of ecosystems. Such statistical analyses are often confounded by left-censoring of analytical results. We review the different points of view and propose a compromise which recognizes these conflicting perspectives.