Hudson River study

In more recent studies, Feng et al. (1999) calculated a Th water column residence time of 2 to 12 days in the Hudson River estuary. McKee et al (1986b) determined that " Th was removed on a time scale of a day or less in the very particle-rich environment of the Yangtze River estuary. In the Amazon River estuary, another particle-rich environment, McKee et al. (1986a) determined that the residence time of dissolved " Th ranged from 2 to 4 days. McKee et al. (1986a) also calculated apparent distribution... 

J. J. Boon, K. Keune and J. Zucker, Imaging analytical studies of lead soaps aggregating in preprimed canvas used by the Hudson River School painter F. E. Church, Microscopy and Microanalysis, ll(Suppl. 2), 444 445 (2005). 

Beller and Simoneit [20] studied the occurrence of hexachlorophene in extracts of estuarine sediments taken from the Hudson River. Hexachlorophene was detected only in the humic acid fractions of the samples, indicating that it could bind strongly to organic matter and was highly resistant to degradation in that form. 

The first scientists to investigate the coastal atmospheric presence of APs were Van Ry and Dachs, in a study conducted in the Hudson river estuary. GC-MS analyses showed that atmospheric NP isomer mixtures have a similar composition to technical mixtures, with relatively high total concentrations in the range of 0.0002—0.069 xg m-3 in the gas phase, and 0.0001-0.051 p,gm-3 in the aerosol phase. These concentrations are higher than those of polycyclic aromatic hydrocarbons and up to two orders of magnitude higher than polychlorinated biphenyl concentrations in impacted urban-industrial areas [32]. 

The studies suggest, for instance, that the Hudson River carries the waste of some 16 tons of cocaine consumed per year in New York. The Rhine in Germany carries the waste of some 9 tons of cocaine consumed along its... 

Complementary work by the GE team on Hudson River sediments has utilized a microcosm system to understand better both the aerobic and anaerobic transformations that occur in stationary sediments. These studies provided further evidence that the naturally occurring microorganisms shown in the Hudson River field trial have the potential to attack Aroclor 1242 at rapid rates both aerobically and anaerobically. These results are helping to further our understanding of the fate of released PCBs in river sediments (Fish Principe, 1994). 

Even though substrate quality (i.e., chemical composition) is widely believed to be an important factor influencing microbial utilization of DOM, there are relatively few studies relating the composition and bioavailability of DOM. Sensitive assays for the measurement of the relative activities of various extracellular enzymes can provide an indication of the chemical composition of the bioreactive components of DOM (Sinsabaugh and Findlay, 1995 Findlay et al., 1998). The enzymatic potential of bacterial populations appears to respond fairly rapidly to seasonal changes in DOM composition in the Hudson River system. These observations clearly indicate that the chemical composition of DOM influences the microbial processing of DOM. 

Hetling, L., Horn, E., Toftlemire, J. (1978) Summary of Hudson River PCB Study Results. New York State Department of Environmental Conservation, Tech. Report No. 51, Albany, New York. 

Asian clam, Potamocorbula amurensis, in 1987 (Carlton et al., 1990). The invasive Asian Date mussel, Musculista senhousia, has invaded the west coast of the United States altering community dynamics, and has now spread to Western Australia, New Zealand, and the Mediterranean (Mistri, 2002). One of the more notable bivalve invasions, by the zebra mussel (Dreissena polymorpha), has proven to be as devastating and expansive across U.S. rivers, lakes, and estuaries as predicted in early studies (Strayer and Smith, 1993). For example, these mussels can filter a volume of water equivalent to the entire freshwater region of the Hudson River about every 2 d this has dramatically altered the total suspended load and the phytoplankton community (Roditi et al., 1996). Similarly, invasion of wetland plant species, such as Phragmites australis, has resulted in displacement of dominant marsh Spartina spp. along the eastern U.S. coast (see more in chapter 8) (Chambers et al., 2003). 

Whereas the studies described above have sought to identify the main sources, it is more likely that there are multiple sources of POPs to urban centres, some of which show temperature dependence while others do not. This was the conclusion of Rodenburg and co-workers based on a variety of measurements and statistical methods that they used to study PCBs in the Hudson River estuary and the Philadelphia-Camden region (Totten et al., 2004 Asher et al, 2007 Du and Rodenburg, 2007 Du et al., 2008, 2009). 

Lohmann R., Nelson E., Eisenreich S. J., and Jones K. C. (2000) Evidence for dynamic air-water exchange of PCDD/ Fs a study in the Raritan Bay/Hudson River estuary. Environ. Sci. Technol. 34, 3086-3093. 

Anaerobic Metabolism, To examine the extent of anaerobic chloroaromatic metabolism, we undertook a study in which sediments from the upper Hudson River, the lower Hudson River, and the East River were used as inoculum (33, 34). Each monochlorophenol isomer (2-, 3-, and 4-chloro-phenol, CP) and each monochlorobenzoate isomer (2-, 3-, and 4-chloroben-zoate, CB) was used as substrate. Duplicate or triplicate cultures were established under three anaerobic conditions denitrifying, sulfidogenic, and methanogenic. The initial concentration of each of the chloroaromatic compounds was 0.1 mM incubation was at 30 °C in the dark. Substrates were quantified by high-pressure liquid chromatography N2 and CH4 were analyzed by gas chromatography nitrate and sulfate were determined by colorimetric methods or by ion chromatography (33, 34). 

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