Sorption and transport of 17beta-estradiol and testosterone in undisturbed soil columns

Land-applied domestic animal wastes contain appreciable amounts of 17beta-estradiol (henceforth, estradiol) and testosterone. These sex hormones may be transported through soil to groundwater and streams, where they may adversely affect the environment. Previous column transport studies with these hormones used repacked soil and did not consider preferential flow. We, therefore, determined the sorption and transport characteristics of estradiol and testosterone in undisturbed soil columns (15-cm i.d. by 32-cm height). In the sorption experiment, isotherms for estradiol and testosterone were nonlinear with Freundlich exponents (n) less than one. Sorption of both hormones decreased with soil depth, and estradiol sorbed more strongly than testosterone. Average estradiol Freundlich sorption coefficients (K(f)) values were 36.9 microg(1 - n) mL(n) g(-1) for the 0- to 10-cm soil depth and 25.7 microg(1 - n) mL(n) g(-1) for the 20- to 30-cm soil depth. Average testosterone K(f) values were 26.7 microg(1 - n) mL(n) g(-1) for the 0- to 10-cm soil depth and 14.0 microg(1 - n) mL(n) g(-1) for the 20- to 30-cm soil depth. In the transport experiment, 27% of the estradiol and 42% of the testosterone leached through the soil columns. Approximately 50% of the remaining soil-bound hormones were sorbed in the top 10 cm of soil. In almost all instances, breakthrough concentrations of estradiol, testosterone, and a chloride tracer peaked simultaneously. Simultaneous breakthrough and HYDRUS-1D transport parameters indicated both chemical and physical nonequilibrium processes affected hormone transport. This suggests hormones placed on soil surfaces may contaminate groundwater under conditions of preferential flow.     

Evaluation of PFAS treatment technology: Alkaline ozonation

A bench‐scale treatability study was performed to evaluate the effectiveness of alkaline ozonation on removing per‐ and polyfluoroalkyl substances (PFAS) present in groundwater at a former industrial site in Michigan. The study involved testing the PFAS‐impacted groundwater under alkaline ozonating conditions under a range of experimental conditions, including modifying pH, hydrogen peroxide‐to‐ozone molar ratio doses, length of ozonation pretreatment times, and sampling techniques. PFAS‐spiked samples were used to determine if inorganic ions such as fluoride (F^?), sulfate (SO₄^2?), formate (HCOO^?), acetate (CH₃COO^?), and trifluoroacetate (CF₃COO^?) were generated or if there were decreases in total organic fluorine resulting from PFAS treatment. The results from all tests indicate that decreases in PFAS concentrations were due to a combination of removal and destructive mechanisms with enhanced removal under acidic pH ozonation pretreatment conditions. Short‐chain PFAS concentrations increased during the experiments followed by an overall decrease in concentration under continuous alkaline ozonation conditions. Reductions in concentrations in perfluorooctane sulfonic acid of 75–97% were observed. Reductions in concentrations were also observed in other PFAS such as 6:2 FTS, PFHxS, PFOA, and PFNA. To our best knowledge, this is the first time that alkaline ozonation has been performed on PFAS‐impacted water while monitoring a larger suite of PFAS analytes in addition to destruction byproducts. Treatment of PFAS under the conditions discussed in this paper suggests that alkaline ozonation may be a viable remediation option for PFAS‐impacted waters.     

Sizing and Costing of fabric Filters Part II: Costing Considerations

This is the second of a two-part article that reviews baghouse filtration theory, presents size estimating methods, and gives costing procedures for a variety of baghouse types and sizes. Part I of the article discussed theory and sizing; this part presents costing. Information is given for estimating total capital investment including separate costs for the bare baghouse (five types), bags, and, where needed, cages and Venturis. Factors are given for installation and for indirect costs. Direct and indirect annual costs are discussed. An example problem is given. The material in this article is taken primarily from the EAB Control Cost Manual.     

Effect of fasting on the pattern of urinary arsenic excretion

Millions of people in some of the poorest regions of the world are exposed to high levels of arsenic through drinking contaminated water. It has been reported that development of cancer caused by arsenic exposure in such populations is dependent on dietary and nutritional factors which can modulate arsenic metabolism. Many people in arsenic exposed regions of Bangladesh and India practice fasting for at least one month every year when they refrain from consumption of food and fluid during daylight hours. How such practices may modulate arsenic metabolism has not been previously investigated. This study investigated this issue by determining total arsenic and its species in urine samples from a group of 29 unexposed volunteers at the beginning of the fasting and at the end of approximately 12 h of fasting period. Inductively coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography (HPLC) coupled with ICP-MS was used to measure the total arsenic and arsenic speciation in the urine samples, respectively. The mean total levels of arsenic at the beginning of fasting (18.3 microg g(-1) creatinine) and at the end of approximately 12 h of fasting (17.7 microg g(-1) creatinine) did not differ significantly (p > 0.05). However, the percentages of urinary arsenic as the methylated arsenic species methylarsonate (MA) were found to be significantly different (p < 0.05) and this species was observed more frequently at the end of fasting, although its overall concentration was similar. There were no significant differences (p > 0.05) in both the concentrations and percentages of other urinary arsenic species detected, namely arsenobetaine (AB) and dimethylarsinate (DMA). Arsenite (As(III)) and arsenate (As(V)) were also analyzed, but were not detected. We conclude that fasting for a period of 12 h results in a significant increase in the percentage of urinary arsenic as MA, and its frequency of detection in the volunteers at the end of the fasting period is almost nine fold higher. This suggests that metabolism of arsenic is altered by fasting.     

Trade union approach to control of toxic substances

Summary The paper deals with some of the problems associated with toxic substances in the work environment, it illustrates these by reference to case studies. It also looks at the involvement of Trade Unions in health and safety issues. It points out flaws and limitations of the present legislative measures; the need to detect toxic substances before they are introduced into the workplace. There is a strong argument for new procedures and regulations to control and license toxic substances; it sets out criteria advocated by Trade Unions towards achieving this. It shows how a whole new strategy has to be agreed to, a strategy that puts as its priority the health of the population as a whole.General Secretary of the Association of Technical and Managerial Staffs. A major Trade Union for scientist, technologists and technicians etc. in the UK.     

Spatial patterns of forest characteristics in the western United States derived from inventories.

In the western United States, forest ecosystems are subject to a variety of forcing mechanisms that drive dynamics, including climate change, land-use/land-cover change, atmospheric pollution, and disturbance. To understand the impacts of these stressors, it is crucial to develop assessments of forest properties to establish baselines, determine the extent of changes, and provide information to ecosystem modeling activities. Here we report on spatial patterns of characteristics of forest ecosystems in the western United States, including area, stand age, forest type, and carbon stocks, and comparisons of these patterns with those from satellite imagery and simulation models. The USDA Forest Service collected ground-based measurements of tree and plot information in recent decades as part of nationwide forest inventories. Using these measurements together with a methodology for estimating carbon stocks for each tree measured, we mapped county-level patterns across the western United States. Because forest ecosystem properties are often significantly different between hardwood and softwood species, we describe patterns of each. The stand age distribution peaked at 60-100 years across the region, with hardwoods typically younger than softwoods. Forest carbon density was highest along the coast region of northern California, Oregon, and Washington and lowest in the arid regions of the Southwest and along the edge of the Great Plains. These results quantify the spatial variability of forest characteristics important for understanding large-scale ecosystem processes and their controlling mechanisms. To illustrate other uses of the inventory-derived forest characteristics, we compared them against examples of independently derived estimates. Forest cover compared well with satellite-derived values when only productive stands were included in the inventory estimates. Forest types derived from satellite observations were similar to our inventory results, though the inventory database suggested more heterogeneity. Carbon stocks from the Century model were in good agreement with inventory results except in the Pacific Northwest and part of the Sierra Nevada, where it appears that harvesting and fire in the 20th century (processes not included in the model runs) reduced measured stand ages and carbon stocks compared to simulations.     

Spatial and temporal variability in the assemblage structure of fishes associated with mangroves (<Emphasis Type="Italic">Avicennia marina</Emphasis>) and intertidal mudflats in temperate Australian embayments

Fishes using mangrove (Avicennia marina) and mudflat habitat were sampled using three different types of gear (seine, fyke, and gill nets) at three sites within each of two large embayments through time (quarterly) between January 2002 and November 2002. At least 41 species of fish were sampled, of which 78% were marine, 17% were estuarine, and 5% were freshwater. Juveniles were sampled in 41% of the species, and 5 and 6 species occurred exclusively in mangrove and mudflat habitats, respectively. The assemblage structure of fishes varied significantly between habitats (for both fyke and seine catches) and between spring and summer (seine catches), but only in one bay. Most of the variability between habitats and times of the year could be explained by differences in abundances of atherinids, mugulids, gobiids, tetraodontids, pleuronectids, and clupeids. Fyke nets sampled mainly juvenile and smaller species of fish. Fish abundance was always greater in mangroves than mudflats (but significantly so at four of the six study sites) and varied significantly between times of the year at one site, while the number of species varied significantly between times of the year at three sites. Gill nets sampled mostly adult/subadult fishes and abundances were greater in mudflats than mangroves at two sites, and in mangroves over mudflats at one site, while species abundance varied between times of the year at two sites. The seine net sampled mainly early post-settlement and small (<20 mm) fishes, more species of which were sampled in mudflat than mangrove during winter and spring, whereas the opposite pattern occurred in summer and autumn. The number of fish sampled with the seine net only varied significantly between habitats in one embayment during summer and spring, when they were larger and smaller, respectively, in mangroves than mudflats. Mangrove habitat in temperate Australian waters supports a richer juvenile fish assemblage than adjacent mudflats, but there is little difference between habitats for the subadult/adult assemblage. Ultimately, the value of mangrove habitats to fishes depends strongly on when and where (bays and sites within bays) the study is done.Communicated by M.S. Johnson, Crawley