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Montano M.D.,Colorado School of Mines | Lowry G.V.,Carnegie Mellon University | Von Der Kammer F.,University of Vienna | Blue J.,Cadmus Group Inc. | Ranville J.F.,Colorado School of Mines
Environmental Chemistry | Year: 2014

The increasing manufacture and implementation of engineered nanomaterials (ENMs) will continue to lead to the release of these materials into the environment. Reliably assessing the environmental exposure risk of ENMs will depend highly on the ability to quantify and characterise these materials in environmental samples. However, performing these measurements is obstructed by the complexity of environmental sample matrices, physiochemical processes altering the state of the ENM and the high background of naturally occurring nanoparticles (NNPs), which may be similar in size, shape and composition to their engineered analogues. Current analytical techniques can be implemented to overcome some of these obstacles, but the ubiquity of NNPs presents a unique challenge requiring the exploitation of properties that discriminate engineered and natural nanomaterials. To this end, new techniques are being developed that take advantage of the nature of ENMs to discern them from naturally occurring analogues. This paper reviews the current techniques utilised in the detection and characterisation of ENMs in environmental samples as well as discusses promising new approaches to overcome the high backgrounds of NNPs. Despite their occurrence in the atmosphere and soil, this review will be limited to a discussion of aqueous-based samples containing ENMs, as this environment will serve as a principal medium for the environmental dispersion of ENMs. © CSIRO 2014. Source


Mudarri D.H.,Cadmus Group Inc.
Journal of Environmental and Public Health | Year: 2016

Two foundational methods for estimating the total economic burden of disease are cost of illness (COI) and willingness to pay (WTP). WTP measures the full cost to society, but WTP estimates are difficult to compute and rarely available. COI methods are more often used but less likely to reflect full costs. This paper attempts to estimate the full economic cost (2014$) of illnesses resulting from exposure to dampness and mold using COI methods and WTP where the data is available. A limited sensitivity analysis of alternative methods and assumptions demonstrates a wide potential range of estimates. In the final estimates, the total annual cost to society attributable to dampness and mold is estimated to be $3.7 (2.3-4.7) billion for allergic rhinitis, $1.9 (1.1-2.3) billion for acute bronchitis, $15.1 (9.4-20.6) billion for asthma morbidity, and $1.7 (0.4-4.5) billion for asthma mortality. The corresponding costs from all causes, not limited to dampness and mold, using the same approach would be $24.8 billion for allergic rhinitis, $13.5 billion for acute bronchitis, $94.5 billion for asthma morbidity, and $10.8 billion for asthma mortality. © 2016 David H. Mudarri. Source


Stankwitz C.,College of William and Mary | Stankwitz C.,Cadmus Group Inc. | Kaste J.M.,College of William and Mary | Friedland A.J.,Dartmouth College
Environmental Science and Technology | Year: 2012

Atmospheric deposition is the primary mechanism by which remote ecosystems are contaminated, but few data sets show how fluxes change and control soil metal burdens at the landform scale. We present mercury (Hg), lead ( 210Pb and total Pb), and cosmogenic beryllium-7 (7Be) measurements in organic (O) soil horizons at high-resolution elevation intervals of ∼60 m from 540 to 1160 m on Camels Hump in northern Vermont, USA. Across this gradient, average O horizon Hg ranges from 0.99 mg m-2 in the low elevation deciduous forest zone to 7.6 mg m-2 in the higher elevation coniferous forest at 1030 m. We measure two pronounced threshold increases in soil metal burdens above 801 and 934 m, corresponding to the two most common altitudes of cloud base, which coincide with changes in vegetation species. Lead-210, a unique tracer of tropospheric deposition, also increased from 3200 Bq m-2 to 11 500 Bq m-2 in O horizons, exhibiting threshold responses at the same elevations as Hg and total Pb. Concentrations of 210Pb and Hg in foliage double from 760 to 900 m elevation, indicating enhanced deposition across the transition from deciduous to coniferous forest. In contrast, 7Be is constant across the entire elevational gradient because of its upper atmospheric source. This indicates that the effects of orographic precipitation have a smaller control on soil contaminant burdens than the coupled cloudwater deposition-vegetation scavenging effect in the presence of upwind sources. By measuring soil contaminants and unique tracers of atmospheric deposition, we show that tropospheric fluxes of Hg and Pb are higher by a factor of 2 in high-elevation coniferous forests than in adjacent lowlands. Total O horizon Hg and Pb burdens increase by over 4-fold with elevation because of the compounding effects of enhanced deposition and longer metal residence times at higher elevations (>50 years). © 2012 American Chemical Society. Source


Boyd G.R.,Cadmus Group Inc.
Journal - American Water Works Association | Year: 2012

Two galvanic pipe-loop couples (lead-copper and lead- bronze) were exposed to controlled changes in water quality (disinfectant, pH, alkalinity, phosphate) and monitored for changes in lead and copper release. Open circuit potential (OCP) profiles were also measured along the junction of dissimilar metals to determine the extent of the zone affected by galvanic coupling. Grab sampling results showed that changes in water quality caused transient (short-lived) increases in lead and decreases in copper that corresponded to the galvanic action of lead on the other coupled metal. OCP measurements showed that the galvanic effect on corrosion potential can induce a shift of up to 600 mV. The extent of the galvanically affected zone was limited, penetrating no more than a few inches from the juncture along the surface of each pipe. Additional testing confirmed strong effects of external versus direct coupling on the OCP profiles in the galvanically affected zone. Source


van Egeren S.J.,801 Progress Rd. | Dodson S.I.,University of Wisconsin - Madison | Torke B.,3119 W. Petty Road | Maxted J.T.,Cadmus Group Inc.
Hydrobiologia | Year: 2011

Zooplankton community composition can be related to natural environmental factors such as lake morphology, lake landscape position, and water chemistry as well as anthropogenic factors such as agricultural and urban land-use. We hypothesized that within-lake factors, such as water chemistry, lake morphology, and human land-use would each be related to zooplankton community structure, but that watershed land-use would be the strongest correlate in southeast Wisconsin lakes. Zooplankton samples, collected every 3 months over a year, from 29 lakes were used to determine how lake and watershed morphology, water quality, and land-use were related to zooplankton community structure in the heavily developed Southeast Wisconsin Till Plain Ecoregion. Forward selection and a variation partitioning procedure were used to determine relative and shared contributions of each suite of variables in predicting zooplankton community structure. Redundancy analysis was used to characterize dominant gradients in pelagic zooplankton communities and related environmental factors and land-use. The major correlates of community structure included summer phosphorus, lake depth and surface area and urban and natural land. Variation partitioning illustrated that phosphorus alone accounts for the greatest part (12%) of community structure. Urban land-uses (residential, commercial and paved land) and lake morphology partially explain zooplankton community variation through combined effects with phosphorus. Small cladocerans and Skistodiaptomus pallidus were associated with higher phosphorus, shallow depth and higher urban land-use, while Daphnia pulicaria dominates in deep lakes with lower phosphorus and less urban land-use. This study contributes to the understanding of factors affecting zooplankton community structure in a largely human developed region and illustrates the importance of eutrophication in structuring zooplankton community composition. © 2011 Springer Science+Business Media B.V. Source

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