A model for the presence of polychlorinated biphenyls (PCBs) in the Willamette River Basin (Oregon)
ABSTRACT The Willamette River drains a 32,000 km2 basin (Basin) in northwestern Oregon. Owing to their persistence and toxicity, polychlorinated biphenyls (PCBs) in resident fish within the Basin at levels above consumption advisory thresholds are a human and environmental health concern. This concern may trigger a Willamette River Total Maximum Daily Load (TMDL) for PCBs, at which time both their probable sources and the mechanism by which they came to be distributed throughout the Basin will be of considerable regulatory interest. Deposition within the Basin of some portion of global primary (1930-1980) and secondary (post-1980) emissions arriving via long-range advective transport in the atmosphere was posited as an explanation. This proposition was explored with a seasonally responsive, dynamic mass balance watershed-scale model that estimated concentrations of toxicologically relevant congeners (PCB-077, -118, -169) in various environmental media over a 90-year period, assuming advective inflow to the Basin's atmosphere to be the only PCB congener source. Model results suggest that rising air concentrations, and associated advective inflows, from increasing primary emissions between 1930 and 1975 (PCB-118 peak inflow, 1970, approximately equal to 11 kg y(-1)) and declining primary and secondary emissionsthereafter, could have yielded congener concentrations observed in air, soil, and fish between 1993 and 2003. The possibility that observed concentrations may be obtainable entirely with inputs from global legacy sources raises questions as to the efficacy of a TMDL directed primarily at local point or area sources. Better characterization of potential sources, and collection of additional soil and air data combined with more sophisticated modeling, appear to be necessary precursors to any PCB TMDL for the Willamette River.
- SourceAvailable from: Vishwajit S Chowdhury
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- "In fish, PCB (118) is the highest congener compared with PCB-105, -156, -167, - 123, -157, -114, -189, -77, -126, -81, or -169 (Bhavsar et al. 2007). In aquatic environment, PCB (118) was detected (Hope 2008; Aksoy et al. 2011). Therefore, we paid attention to bone metabolism by PCB (118) pollution. "
ABSTRACT: To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogenous effects of sex steroids are negligible, were used. PCB (118) was solubilized in dimethyl sulfoxide at a concentration of 10 ppm. At 1 and 2 days after PCB (118) injection (100 ng/g body weight), both osteoclastic and osteoblastic activities, and plasma calcium levels were measured. In an in vitro study, then, both osteoclastic and osteoblastic activities as well as each marker mRNA expression were examined. At 2 days, scale osteoclastic activity in PCB (118)-injected goldfish increased significantly, while osteoblastic activity did not change significantly. Corresponding to osteoclastic activity, plasma calcium levels increased significantly at 2 days after PCB (118) administration. Osteoclastic activation also occurred in the marker enzyme activities and mRNA expressions in vitro. Thus, we conclude that PCB (118) disrupts bone metabolism in goldfish both in vivo and in vitro experiments.Environmental Science and Pollution Research 12/2012; 21(10). DOI:10.1007/s11356-012-1347-5 · 2.76 Impact Factor
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- "Atmospheric falling dust includes dry and wet dust, of which wet dust has been widely researched and documented in the literature (Hope 2008; Chantara and Chunsuk 2008). "
ABSTRACT: Guangzhou is the central city in the Pearl River Delta (PRD), China, and is one of the most polluted cities in the world. To characterize the ambient falling dust pollution, two typical sampling sites: urban (Wushan) and suburban (University Town) areas in Guangzhou city were chosen for falling dust collection over 1 year at time intervals of 1 or 2 months. The flux of dry deposition was calculated. In addition, mineral composition and morphology of atmospheric falling dust were studied by X-ray diffraction, scanning electron microscopy, and microscopic observation. The results revealed that the dust flux in Guangzhou city was 3.34-3.78 g/(m(2) month) during the study period. The main minerals in the dust were quartz, illite, calcite, kaolinite, gypsum, plagioclase, dolomite, and amorphous matter. The morphological types included grained and flaky individual minerals, chain-like aggregates, spherical flying beads, and irregular aggregates, with the chain-like and spherical aggregates indicators of industrial ash. The major dusts were derived from industrial and construction activities. The gypsum present in the dust collected in winter season was not only derived from cement dust but may also have originated from the reaction of calcic material with sulfuric acids resulting from photooxidation of SO(x) and NO(x), which confirmed serious air pollution due to SO(x) and NO(x) in Guangzhou. The abatement of fossil fuel combustion emissions and construction dust will have a significant beneficial effect on dust reduction.Air Quality Atmosphere & Health 09/2010; 3(3):139-147. DOI:10.1007/s11869-009-0062-y · 1.46 Impact Factor
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ABSTRACT: In 2011, as part of an update to its state water quality standards (WQS) for protection of human health, the State of Oregon adopted a fish consumption rate of 175 g/day for freshwater and estuarine finfish and shellfish, including anadromous species. WQS for the protection of human health whose derivation is based in part on anadromous fish, create the expectation that implementation of these WQS will lead to lower contaminant levels in returning adult fish. Whether this expectation can be met is likely a function of where and when such fish are exposed. Various exposure scenarios have been advanced to explain acquisition of bioaccumulative contaminants by Pacific salmonids. This study examined 16 different scenarios with bioenergetics and toxicokinetic models to identify those where WQS might be effective in reducing polychlorinated biphenyls (PCBs)--a representative bioaccumulative contaminant--in returning adult Fall chinook salmon, a representative salmonid. Model estimates of tissue concentrations and body burdens in juveniles and adults were corroborated with observations reported in the literature. Model results suggest that WQS may effect limited (< approximately 2 ×) reductions in PCB levels in adults who were resident in a confined marine water body or who transited a highly contaminated estuary as out-migrating juveniles. In all other scenarios examined, WQS would have little effect on PCB levels in returning adults. Although the results of any modeling study must be interpreted with caution and are not necessarily applicable to all salmonid species, they do suggest that the ability of WQS to meet the expectation of reducing contaminant loadings in anadromous species is limited.Integrated Environmental Assessment and Management 07/2012; 8(3):553-62. DOI:10.1002/ieam.1280