Identifying hydrologically sensitive areas: bridging the gap between science and application

Researchers have noted that current water quality protection strategies, like nutrient management plans, lack a sound hydrological underpinning for pollutant transport processes. This is especially true for areas like the northeastern U.S. where copious research has shown that variable source area hydrology largely governs runoff generation. The goal of this study was to develop a scientifically justified method to identify the locations that generate overland flow. Furthermore, this methodology must be computationally simple enough that it can be utilized or incorporated into nutrient management plans and other established water quality tools. We specifically tested the reliability of the 'distance from a stream,'D(s), and the 'topographic index,'lambda, to predict areas with a high propensity for generating overland flow, i.e. hydrologically sensitive areas (HSA). HSAs were defined by their probability of generating runoff, P(sat), based on 30 year simulations using a physically based hydrological model. Using GIS, each location's P(sat) was correlated with D(s) and lambda. We used three Delaware Co., NY watersheds in the New York City watershed system with areas varying in size from 1.6 to 37 km2 and with forested and agricultural land uses. The topographic index gave stronger, more regionally consistent correlations with P(sat) than did D(s). Equations correlating lambda and P(sat) for each month are presented and can be used to estimate hydrological sensitivity in the region surrounding our study watersheds, i.e. in Delaware Co. This work is currently being incorporated into an Internet Mapping System to facilitate user-friendly, on-line identification of HSAs.     

Changes in the salinity of the Euphrates River system in Iraq

The water salinity of the Euphrates River as it enters Iraq, expressed as total dissolved solids (TDS), has more than doubled compared to that of 1973. Downstream of Al Hindia Barrage, south of Baghdad, the salinity has increased gradually over the last 30 years. The annual average TDS at Al Nassiriah, in the lower reaches of the Euphrates, has increased from 1,080 ppm in 1979 to more than 4,500 ppm in 2001. Water quality of the Euphrates within Iraq has deteriorated due to the decreased flow that is entering Iraq, diverted flows to the river from Al Tharthar Lake, and irrigation-return flow. The decreased flow from upstream sources was due to reservoir construction projects. Water from Al Tharthar Lake and from irrigation return flow is being diverted to the Euphrates to compensate for the upstream deficit. An environmental flow rate of 178 m³/s (annual minimum flow, 5.6 bcm or about one-third of historic minimum flow) is proposed as the minimum discharge that must be flowing into Iraq to preserve the environment of the Euphrates River in Iraq. A flow of twice this amount would allow more reasonable downstream management with an input average salinity of 760 ppm.     

Concentrations of decabromodiphenyl ether in air from Southern Ontario: implications for particle-bound transport

Atmospheric concentrations are reported for the main component of the brominated flame retardant decaBDE (BDE-209) in air samples collected from Southern Ontario for the period January 23-June 06, 2002. Levels ranged from below detection to 105pgm(-3) with virtually all of BDE-209 being trapped by the filter and thus deduced to be sorbed to aerosol particles. Thus, it is likely that the long-range atmospheric transport (LRAT) of BDE-209 is controlled by the transport characteristics of the aerosols. This conclusion that BDE-209 does not have the same potential for LRAT as other more volatile PBDEs is subject to possible complications arising from the uncertainties about the LRAT potential of aerosols.     

Postnatal management of prenatally diagnosed abdominal masses and anomalies

Rapid advancement in fetal diagnostic imaging has increased our ability to diagnose a multitude of anomalies in the prenatal period. The purpose of this chapter is to review our current understanding of prenatally diagnosed intra-abdominal lesions, and describe the current guidelines for the postnatal management and subsequent outcome for these lesions. Copyright © 2008 John Wiley & Sons, Ltd.     

Advanced paternal age,infertility, and reproductive risks: A review of the literature

Advanced paternal age (APA) is associated with infertility and other reproductive risks. Studies looking at APA and outcomes have used different paternal age cut-offs, which has complicated systematic evaluations of reproductive risk associated with paternal aging. This review of the literature suggests that the impact of paternal aging on adverse reproductive outcomes is small, but significant. Studies suggest the incidence of paternal age effect disorders attributed to de novo autosomal dominant mutations is less than 0.5%. Other risks associated with APA include infertility, miscarriage, birth defects, poor neurodevelopmental outcomes, and childhood cancer. Although the increasing prevalence of APA has mirrored the rise in maternal age, this topic has not received similar attention. In this review, we summarize the available literature on the reproductive risks associated with APA to provide a framework for comprehensive genetic counseling and evidence-based management of APA pregnancies.     

Transport of lead and diesel fuel through a peat soil near Juneau, AK: a pilot study

A set of peat column experiments was used to determine the transport potential of lead (Pb) and diesel range organics (DRO) in palustrine slope wetlands near Juneau, AK. This project is important to southeast Alaskan communities because limited land resources are forcing development of regional wetlands. This study was instigated by concerns that proposed modifications to a nearby rifle range using DRO-contaminated soil posed a potential risk to an anadromous fish-bearing stream 250 m from the site. Three pairs of peat columns were extracted from the rifle range for analysis, one pair along and two pairs across the natural bedding planes of the soil. One column in each pair was spiked with Pb and DRO and the other was used as a control. Approximately 1-year worth of water (171 cm) was passed through each column and leachate was collected at regular intervals. The results showed that substantial DRO transport only occurred along the bedding planes. Leads was surprisingly mobile, both along and across the bedding planes with estimated soil-water partition coefficients several orders of magnitude lower than commonly published values, probably because the peat was heavily Pb-loaded by lead from bullets and because the peat's acidic, organic-rich environment enhanced Pb mobility. The chemical outflow behavior agreed with a simple macropore transport model. These results underscore the need for caution when developing regional wetlands.