Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the North.

Spring flooding of the Red River of the North (RR) is common, but little information exits on how these flood events affect water and overbank sediment quality within an urban area. With the threat of the spring 2009 flood in the RR predicted to be the largest in recorded history and the concerns about the flooding of farmsteads, outbuildings, garages, and basements, the objectives of this study, which focused on Fargo, ND, and Moorhead, MN, were to assess floodwater quality and to determine the quantity and quality of overbank sediment deposited after floodwaters recede and the quality of soil underlying sediment deposits. 17ß-Estradiol was detected in 9 of 24 water samples, with an average concentration of 0.61 ng L. Diesel-range organics were detected in 8 of 24 samples, with an average concentration of 80.0 µg L. The deposition of sediment across locations and transects ranged from 2 to 10 kg m, and the greatest mass deposition of chemicals was closest to the river channel. No gasoline-range organics were detected, but diesel-range organics were detected in 26 of the 27 overbank sediment samples (maximum concentration, 49.2 mg kg). All trace elements detected in the overbank sediments were within ranges for noncontaminated sites. Although flooding has economic, social, and environmental impacts, based on the results of this study, it does not appear that flooding in the RR in F-M led to decreased quality of water, sediment, or soil compared with normal river flows or resident soil.

Effects of liquid swine manure on dissipation of 17ß-estradiol in soil.

17ß-estradiol (E2), a natural estrogenic hormone, degrades within hours and bind strongly to soils and sediments; however, estrogens are frequently detected in the environment at concentrations that impact water quality. Colloidal (COC) and dissolved (DOC) organic carbon may enhance the persistence and mobility of E2. Soil batch experiments were used to identify the persistence and sorption of radiolabeled E2 dissolved in solutions of (i) COC/DOC derived from liquid swine manure and (ii) CaCl(2). Estradiol disappeared from the aqueous phase before 7 d in the CaCl(2) solution, yet persisted throughout the duration of the 14 d experiment in the liquid manure solution. There was also concomitant formation of estrone (E1; a metabolite of E2) as E2 dissipated in sterile batch experiments, which was attributed to abiotic oxidation. The liquid manure solution appeared to interact with the estrogen and/or oxidation reaction sites, reducing E2 degradation. Furthermore, the liquid manure solution reduced E2/E1 binding to the soil surface resulting in more E2/E1 in the aqueous layer compared to the CaCl(2) solution. Ultrafiltration results of liquid manure indicated that ∼1/3 of E2 was associated with COC, which may be responsible for the reduced degradation and sorption of E2 in the liquid manure solution.

Inverse analyses of transport of chlorinated hydrocarbons subject to sequential transformation reactions.

Chemical and biological transformations can significantly affect contaminant transport in the subsurface. To better understand such transformation reactions, an equilibrium-nonequilibrium sorption transport model, HYDRUS-1D, was modified by including inverse solutions for multiple breakthrough curves resulting from the transport of solutes undergoing sequential transformations. The inverse solutions were applied to miscible-displacement experiments involving dissolved concentrations of trichloroethylene (TCE) undergoing reduction and/or transformations in the presence of zero-valent metal porous media (i.e., iron or copper-coated iron filings) to produce ethylene. The inverse model solutions provided a reasonable description of the transport and transformation processes. Simultaneous fitting of multiple breakthrough curves of TCE and ethylene placed additional constraints on the inverse solution and improved the reliability of parameter estimates. Confidence intervals of optimized parameters were reduced significantly in comparison with those obtained by fitting TCE breakthrough curves independently. Further evidence for accurate parameter estimates was given when the parameter values agreed with previously reported values from independent batch and degradation experiments. Optimized values of the normalized degradation rates for the equilibrium (1.4 x 10(-4) to 7.2 x 10(-5) L h(-1)m(-2)) and nonequilibrium (1.2 x 10(-4) to 5.5 x 10(-5)L h(-1)m(-2)) models compared well with values (0.03 to 6.5 x 10(-5) L h(-1) m(-2)) obtained from previous studies. The estimated TCE-iron sorption coefficients (0.52 to 2.85 L kg(-1)) were also consistent with a previously reported value (1.47 L kg(-1)).

Accessory equipment considerations with respect to MRI compatibility.

The MR Section of The National Electrical Manufacturers Association (NEMA), in response to a request from the Food & Drug Administration (FDA), recently issued a position paper to address generic issues related to the compatibility of accessory equipment produced by third party equipment manufacturers or MR equipment users and intended to be used in conjunction with MR equipment or within the MR scanning room. The recommendations concern scanning accessories, such as radiofrequency (RF) coils, patient monitoring equipment and injectors, as well as patient comfort accessories and positioning devices. The following issues related to safety performance are discussed: (a) the interaction of the equipment with the MR scanner, (b) interactions of the MR scanner with the equipment, and (c) potential safety hazards for patients and staff that can be posed by accessory equipment in the MR scan environment. The recommendations are based on combined input from NEMA member companies who manufacture MR systems and MR accessories and are presented for consideration in the design of MR accessory products and incorporation of these concepts into testing plans to ensure MR compatibility of third party devices.

Infrared eye injury not due to radiant warmer use in premature neonates.

OBJECTIVE: Exposure to far-wavelength infrared radiation (lambda > 2000 nm) may cause corneal opacity, miosis, and delayed cataracts (onset > 30 days). Near-wavelength infrared exposure (lambda < 1000 nm) may focus on the retina, causing burns; however, early eye examinations in neonates nursed under radiant warmers have failed to reveal acute injuries. Our purpose is to report long-term ophthalmologic outcome in infants treated under radiant warmers from birth. PARTICIPANTS AND METHODS: We report findings from eye examinations in infants followed up to a median age of 2 years, 9 months (range, 1 to 75 months), for (1) 33 infants nursed exclusively under radiant warmers for up to 5 days postnatally (mean [+/- SD] birth weight, 1.16 +/- 0.24 kg; mean gestation, 30 +/- 2 weeks) and (2) 14 convection-warmed incubator-nursed infants (1.26 +/- 0.22 kg, 31 +/- 2 weeks), who were slightly more mature. MAIN RESULTS: A trend toward retinopathy of prematurity was noted as occurring more frequently in the radiant warmer-nursed infant population, and one infant in that group was blind. However, no macular burns and no permanent corneal, lens, or other anterior segment injuries were observed. CONCLUSION: Preliminary findings do not support permanent eye damage attributable to near- or far-wavelength infrared injury in neonates nursed under radiant warmers.