Variation of Aulacoseira granulata as an eco-pollution indicator in subtropical large river Ganga in India: a multivariate analytical approach

Environmental Science and Pollution Research - Aulacoseira granulata (Ehrenberg) Simonsen 1979 are considered as the eco-variable species which varies in density and diversity along with their...     

Characterization of Emissions of Volatile Organic Compounds from Interior Alkyd Paint

ABSTRACT

Alkyd paint continues to be used indoors for application to wood trim, cabinet surfaces, and some kitchen and bathroom walls. Alkyd paint may represent a significant source of volatile organic compounds (VOCs) indoors because of the frequency of use and amount of surface painted. The U.S. Environmental Protection Agency (EPA) is conducting research to characterize VOC emissions from paint and to develop source emission models that can be used for exposure assessment and risk management. The technical approach for this research involves both analysis of the liquid paint to identify and quantify the VOC contents and dynamic small chamber emissions tests to characterize the VOC emissions after application. The predominant constituents of the primer and two alkyd paints selected for testing were straight-chain alkanes (C9–C12); C8–C9 aromatics were minor constituents. Branched chain alkanes were the predominant VOCs in a third paint. A series of tests were performed to evaluate factors that may affect emissions following application of the coatings. The type of substrate (glass, wallboard, or pine board) did not have a substantial impact on the emissions with respect to peak concentrations, the emissions profile, or the amount of VOC mass emitted from the paint. Peak concentrations of total volatile organic compounds (TVOCs) as high as 10,000 mg/m³ were measured during small chamber emissions tests at 0.5 air exchanges per hour (ACH). Over 90% of the VOCs were emitted from the primer and paints during the first 10 hr following application. Emissions were similar from paint applied to bare pine board, a primed board, or a board previously painted with the same paint. The impact of other variables, including film thickness, air velocity at the surface, and air-exchange rate (AER) were consistent with theoretical predictions for gas-phase, mass transfer-controlled emissions. In addition to the alkanes and aromatics, aldehydes were detected in the emissions during paint drying. Hexanal, the predominant aldehyde in the emissions, was not detected in the liquid paint and was apparently an oxidation product formed during drying. This paper summarizes the results of the product analyses and a series of small chamber emissions tests. It also describes the use of a mass balance approach to evaluate the impact of test variables and to assess the quality of the emissions data.     

UVΑ pre-irradiation to P25 titanium dioxide nanoparticles enhanced its toxicity towards freshwater algae Scenedesmus obliquus

Environmental Science and Pollution Research - There has recently been an increase in the usage of TiO2 nanoparticles (NPs). P25 TiO2 NPs, a mixture of anatase and rutile phase in 3:1 ratio, are...     

Mesoporous carbon nanospheres derived from agro-waste as novel antimicrobial agents against gram-negative bacteria

Environmental Science and Pollution Research - Porous carbon nanospheres were synthesized from agro-waste garlic peels by a one-pot facile and easy to scale-up pyrolysis method. Surface morphology...     

Inferring pollution records in sediment cores from transitional environments of Marquelia coast,Guerrero, Mexico

Environmental Science and Pollution Research - The vertical distribution pattern and concentrations of elements (Fe, Al, Ca, Mg, Mn, Cr, Cu, Ni, Co, Pb, Zn, and As) in the estuarine and lagoon...     

Agricultural livelihood transition in the southern Yucatán region: diverging paths and their accompanying land changes

Land change science has demonstrated that rural livelihoods around the world both drive and reflect changing environmental regimes and political economic/structural transformations. This article explores the relationship between increasingly globalized rural livelihoods and in-place land change, assessing results from social surveys of smallholding households in the southern Yucatán region. We examine evidence for a transition in agricultural livelihood strategies as smallholders adjust to changing political economic and institutional conditions, and link these transitioning strategies to land use changes. Based on household surveys in 1997 and 2003, we comparatively assess both changes in the selection of livelihood strategies and in the land use and cover impacts of those strategies. Our results indicate that although impacts of given strategies have changed little over this period, there are increasing proportions of households pursuing two divergent adjustment paths—one of agricultural withdrawal and one of agricultural intensification and commercialization. We investigate what sociodemographic characteristics differentiate the groups of households following distinct livelihood strategies. Our findings point to the possibility of simultaneous and contradictory land change outcomes as smallholders adjust in different ways to their intensified incorporation into global economies.