Hg Vapor Emission from Broken Compact Fluorescent Lamps (CFLs) in an Acrylic Chamber

The United States Environmental Protection Agency/Environmental Response Team (US EPA/ERT), in collaboration with St. John's College, Dr. B. R. Ambedkar University, Agra, India, is conducting a study to determine Hg vapor emission rates resulting from broken compact fluorescent lamps (CFLs) in a residential setting. The overall objectives of the study are to determine Hg vapor emission data and provide homeowners with cleanup procedures and disposal options for broken CFLs. Most of the currently available CFLs in the US market are manufactured in China for US companies. Several different types of CFLs were purchased from local stores and their Hg content was determined. Based on previous studies, such as the 2011 study by Singhvi and colleagues, five popular spiral CFLs were selected for emission studies in an acrylic chamber. This study found that Hg vapor emissions from CFLs may be significantly greater than those from beads of liquid Hg with weights comparable to the Hg content of the CFLs. The average 24-hour Hg loss into the atmosphere from CFLs broken on a plastic surface ranged from 0.6% to 22% of the bulb content, while that for CFLs broken on carpet ranged from 2.6% to 28%. Projections for a 12 foot × 9.33 foot × 8 foot (25.4 m³) room based on the chamber measurements in this study indicate that CFL breakage in some household settings may produce 24-hour Hg concentrations above the 2000 Agency for Toxic Substances and Disease Registry (ATSDR) minimum risk level (MRL) of 0.2 μg/m³, for typical air exchange rates. This study also indicates that Hg emission may not be proportional to exposed surface area based on experiments using liquid Hg with different surface areas.     

Experimental investigation of different-shaped microwave-heated potatoes: thermal and quality characteristics analysis for food preservation

Environmental Science and Pollution Research - Food materials are consumed for nutritional purposes in the form of fruits, vegetables, plants, and meat. These contain proteins, carbohydrates, and...     

Selection and development of efficient consortia for decolorization of metal complex dyes

Decolorization of 18 different metal complex acid dyes was studied with 11 bacterial consortia. Five consortia and five dyes were selected on the basis of maximum decolorization. Among the parameters for optimization, nutrient broth was preferred by all bacterial consortia but one of them showed significant decolorization with Bushnell and Haas medium with or without glucose and yeast extract; hence, this consortium was selected for further studies. Decolorization efficiency was adversely affected beyond 200 mg/L dye and 2% NaCl concentration. Treatment efficiency was increased 2-fold using a developed consortium as compared to original consortium. Changes in the UV-Vis spectra and considerable reduction in chemical oxygen demand of selected metal complex dyes after decolorization prove the efficiency of the consortium for its use. Decolorization of a broad range of metal complex dyes at pH 7.5 ± 0.5, 35 ± 2 °C, and static conditions promises the use of the developed consortium for industrial wastewater treatment.     

Arsenate and arsenite-induced inhibition and recovery in two diazotrophic cyanobacteria Nostoc muscorum and Anabaena sp.: study on time-dependent toxicity regulation

Environmental Science and Pollution Research - Exposure time, metal bio-accumulation, and upregulation of ascorbate-glutathione (AsA-GSH) cycle are the key factor that provide tolerance against...     

Torque Production Using Handwheels of Different Size During a Simulated Valve Operation Task

Opening and closing valves in industrial facilities often requires operators to use bars and wrenches as levers (cheaters) in order to overcome initial actuation forces. In order to determine more appropriate operational specifications, the maximum torque production capability was measured when 12 male participants used 4 different valve handwheels at 3 different heights and 2 different angles (in relationship to the coronal plane). The results indicate that the participants produced significantly greater torque when the largest of the 4 wheels (40.6 cm diameter) was used than when the medium (22.9 cm), small (20.3 cm), and handled (17.8 cm) handwheels were used. Although the main effect of heights was found to be statistically significant, post-hoc analyses between the heights found them to be, essentially, equal. In addition, the vertical and horizontal wheel orientations were not found to be different. The results are applicable to all industries where handwheels are used and applicable to valve manufacturers for designing operational torque specifications below the values found in this study.     

Torque Production Using Hand Cranks in a Simulated Gear-Operated Valve Opening Task

Hand cranks are used in a variety of industries to actuate valves and in other gear-operated applications. In order to evaluate these types of operations and their compatibility with operator strength capabilities, a rotational dynamometer was used to measure torque production capability of operators using a hand crank at different heights and angles (with respect to the coronal plane). The tests were conducted for both clockwise and counterclockwise rotations using the dominant arm of each test participant. A total of 18 tests were completed by each of five male right-handed test participants. A 0° declination angle, counterclockwise operation, and both 40.65 cm and 60.96 cm heights were found to be associated with the greatest torque production capabilities.     

Design Variables Associated with Fiberglass/Fly Ash Fabric Filter Cleaning

This paper documents the variation in pressure drop and collection efficiency for fiberglass/fly ash fabric filter systems caused by variations in cleaning intensity (reverse air and reverse pulse), air to cloth ratio, and dust loading. Reverse air rates greater than 2 fpm were required to produce stable pressure characteristics. Pulse jet pressure greater than 50 psi reduced collection efficiency. Increased air to cloth ratios produced decreased collection efficiency.     

Estimation and analysis of terrestrial net primary productivity over India by remote-sensing-driven terrestrial biosphere model

Concentrations of cadmium, copper, and lead were determined in surficial sediments and the soft tissues (foot and gills) of swan mussel Anodonta cygnea from two sampling sites in Anzali wetland, which is an internationally important wetland registered in the Ramsar Convention. The metal contents in the mussel species from the studied region were comparable to other world areas. In most cases, the levels of the metals either fell within the range for other areas or were lower. There were significant differences between the tissues for the accumulation of Cd and Pb. Only in the case of Pb accumulation in gills significant differences between the specimens from the selected sampling sites could be observed. Age-related correlations were found in the case of Cu accumulation in foot and Cd levels in gills. No weight-dependent trend could be observed for the accumulation of the three elements. There was significant negative width-dependent relationship in the case of Cu. A significant negative correlation was also found between the maximum shell height and Cu accumulation in the gills. The only association among the elements in the selected soft tissues was found between Cd and Pb. Highly significant differences could be found between the sampling sites from the concentration of the elements in sediments point of view. The pattern of metal occurrence in the selected tissues and sediments exhibited the following descending order: Pb, Cu>Cd for gills, Cu>Pb, Cd for foot, and Cu>Pb>Cd for sediments. The mean concentrations of Cd and Pb in the sediments from the study area were higher than the global baseline values and world average shale. In the case of Cu, our results were somewhat higher than the baseline values but well below the world average shale.     

Biological monitoring of chlorpyrifos exposure to rice farmers in Vietnam

Chlorpyrifos is the most common organophosphate insecticide registered for use in Vietnam and is widely used in agriculture, particularly rice farming. However, chlorpyrifos exposure to and adverse effects on farmers has not been evaluated. In this study, biological monitoring of chlorpyrifos exposure in a group of rice farmers was conducted after a typical application event using back-pack spraying.Urine samples (24 h) were collected from the rice farmers before and post insecticide application. Samples were analysed for 3,5,6-trichloropyridinol (TCP), the major urinary metabolite of chlorpyrifos, using an enzymatic pre-treatment before extraction followed by HPLC-MS/MS. Absorbed Daily Dose (ADD) of chlorpyrifos for farmers were then estimated from urinary TCP levels, expressed as μg g⁻¹ creatinine. The analytical method for urinary TCP had a low detection limit (0.6 μg L⁻¹), acceptable recovery values (80-114%), and low relative percentage differences in duplicate and repeated samples.Post-application chlorpyrifos ADD of farmers varied from 0.4 to 94.2 μg kg⁻¹ (body weight) d⁻¹ with a mean of 19.4 μg kg⁻¹ d⁻¹ which was approximately 80-fold higher than the mean baseline exposure level (0.24 μg kg⁻¹ d⁻¹). Hazard Quotients (ratio of the mean ADD for rice farmers to acute oral reference dose) calculated using acute oral reference doses recommended by United States and Australian agencies varied from 2.1 (Australian NRA), 4.2 (US EPA) to 6.9 (ATSDR).Biological monitoring using HPLC-MS/MS analysis of urinary TCP (24 h) was found to be an effective method for measuring chlorpyrifos exposure among farmers. This case study found that Vietnamese rice farmers had relatively high exposures to chlorpyrifos after application, which were likely to have adverse health effects.