25 results on '"McKee LJ"'
Search Results
2. Suspect Screening and Chemical Profile Analysis of Storm-Water Runoff Following 2017 Wildfires in Northern California.
- Author
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Wang M, Kinyua J, Jiang T, Sedlak M, McKee LJ, Fadness R, Sutton R, and Park JS
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- California, Environmental Monitoring methods, Gas Chromatography-Mass Spectrometry, San Francisco, Surface-Active Agents analysis, Water Pollutants, Chemical analysis, Wildfires
- Abstract
The combustion of structures and household materials as well as firefighting during wildfires lead to releases of potentially hazardous chemicals directly into the landscape. Subsequent storm-water runoff events can transport wildfire-related contaminants to downstream receiving waters, where they may pose water quality concerns. To evaluate the environmental hazards of northern California fires on the types of contaminants in storm water discharging to San Francisco Bay and the coastal marine environment, we analyzed storm water collected after the northern California wildfires (October 2017) using a nontargeted analytical (NTA) approach. Liquid chromatography quadrupole time-of-flight mass spectrometric analysis was completed on storm-water samples (n = 20) collected from Napa County (impacted by the Atlas and Nuns fires), the city of Santa Rosa, and Sonoma County (Nuns and Tubbs fires) during storm events that occurred in November 2017 and January 2018. The NTA approach enabled us to establish profiles of contaminants based on peak intensities and chemical categories found in the storm-water samples and to prioritize significant chemicals within these profiles possibly attributed to the wildfire. The results demonstrated the presence of a wide range of contaminants in the storm water, including surfactants, per- and polyfluoroalkyl substances, and chemicals from consumer and personal care products. Homologs of polyethylene glycol were found to be the major contributor to the contaminants, followed by other widely used surfactants. Nonylphenol ethoxylates, typically used as surfactants, were detected and were much higher in samples collected after Storm Event 1 relative to Storm Event 2. The present study provides a comprehensive approach for examining wildfire-impacted storm-water contamination of related contaminants, of which we found many with potential ecological risk. Environ Toxicol Chem 2022;41:1824-1837. © 2022 SETAC., (© 2022 SETAC.)
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- 2022
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3. Long-term variation in concentrations and mass loads in a semi-arid watershed influenced by historic mercury mining and urban pollutant sources.
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McKee LJ, Bonnema A, David N, Davis JA, Franz A, Grace R, Greenfield BK, Gilbreath AN, Grosso C, Heim WA, Hunt JA, Leatherbarrow JE, Lowe S, Pearce SA, Ross JRM, and Yee D
- Abstract
Urban watersheds are significantly anthropogenically-altered landscapes. Most previous studies cover relatively short periods, without addressing concentrations, loads, and yields in relation to annual climate fluctuations, and datasets on Ag, Se, PBDEs, and PCDD/Fs are rare. Intensive storm-focused sampling and continuous turbidity monitoring were employed to quantify pollution at two locations in the Guadalupe River (California, USA). At a downstream location, we determined loads of suspended sediment (SS) for 14yrs., mercury (HgT), PCBs, and total organic carbon (TOC) (8yrs), total methylmercury (MeHgT) (6yrs), nutrients, and trace elements including Ag and Se (3yrs), DDTs, chlordanes, dieldrin, and PBDEs (2yrs), and PCDD/Fs (1yr). At an upstream location, we determined loads of SS for 4yrs. and HgT, MeHgT, PCBs and PCDD/Fs for 1yr. These data were compared to previous studies, climatically adjusted, and used to critically assess the use of small datasets for estimating annual average conditions. Concentrations and yields in the Guadalupe River appear to be atypical for total phosphorus, DDTs, dieldrin, HgT, MeHgT, Cr, Ni, and possibly Se due to local conditions. Other pollutants appear to be similar to other urban systems. On average, wet season flow varied by 6.5-fold and flow-weighted mean (FWM) concentrations varied 4.4-fold, with an average 7.1-fold difference between minimum and maximum annual loads. Loads for an average runoff year for each pollutant were usually less than the best estimate of long-term average. The arithmetic average of multiple years of load data or a FWM concentration combined with mean annual flow was also usually below the best estimate of long-term average load. Mean annual loads using sampled years were also less than the best estimate of long-term average by a mean of 2.2-fold. Climatic adjustment techniques are needed for computing estimates of long-term average annual loads., (Copyright © 2017 Elsevier B.V. All rights reserved.)
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- 2017
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4. Concentrations and loads of PCBs, dioxins, PAHs, PBDEs, OC pesticides and pyrethroids during storm and low flow conditions in a small urban semi-arid watershed.
- Author
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Gilbreath AN and McKee LJ
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- Dioxins analysis, Halogenated Diphenyl Ethers analysis, Pesticides analysis, Polychlorinated Biphenyls analysis, Polycyclic Aromatic Hydrocarbons analysis, Rain, San Francisco, Water Movements, Environmental Monitoring, Water Pollutants, Chemical analysis
- Abstract
Urban runoff has been identified in water quality policy documents for San Francisco Bay as a large and potentially controllable source of pollutants. In response, concentrations of suspended sediments and a range of trace organic pollutants were intensively measured in dry weather and storm flow runoff from a 100% urban watershed. Flow in this highly urban watershed responded very quickly to rainfall and varied widely resulting in rapid changes of turbidity, suspended sediments and pollutant concentrations. Concentrations of each organic pollutant class were within similar ranges reported in other studies of urban runoff, however comparison was limited for several of the pollutants given information scarcity. Consistently among PCBs, PBDEs, and PAHs, the more hydrophobic congeners were transported in larger proportions during storm flows relative to low flows. Loads for Water Years 2007-2010 were estimated using regression with turbidity during the monitored months and a flow weighted mean concentration for unmonitored dry season months. More than 91% of the loads for every pollutant measured were transported during storm events, along with 87% of the total discharge. While this dataset fills an important local data gap for highly urban watersheds of San Francisco Bay, the methods, the uniqueness of the analyte list, and the resulting interpretations have applicability for managing pollutant loads in urban watersheds in other parts of the world., (Copyright © 2015 Elsevier B.V. All rights reserved.)
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- 2015
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5. Concentrations and loads of suspended sediment and trace element pollutants in a small semi-arid urban tributary, San Francisco Bay, California.
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McKee LJ and Gilbreath AN
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- Ecosystem, Mercury analysis, Quality Control, Rain, San Francisco, Selenium analysis, Bays chemistry, Geologic Sediments analysis, Trace Elements analysis, Water Pollutants, Chemical analysis, Water Quality
- Abstract
Water-quality policy documents throughout the world often identify urban stormwater as a large and controllable impact to sensitive ecosystems, yet there is often limited data to characterize concentrations and loads especially for rare and more difficult to quantify pollutants. In response, concentrations of suspended sediments and silver, mercury and selenium including speciation, and other trace elements were measured in dry and wet weather stormwater flow from a 100% urban watershed near San Francisco. Suspended sediment concentrations ranged between 1.4 and 2700 mg/L and varied with storm intensity. Turbidity was shown to correlate strongly with suspended sediments and most trace elements and was used as a surrogate with regression to estimate concentrations during unsampled periods and to compute loads. Mean suspended sediment yield was 31.5 t/km(2)/year. Total mercury ranged between 1.4 and 150 ng/L and was, on average, 92% particulate, 0.9% methylated, and 1.2% acid labile. Total mercury yield averaged 5.7 μg/m(2)/year. Total selenium ranged between non-detect and 2.9 μg/L and, on average, the total load (0.027 μg/m(2)/year) was 61% transported in dissolved phase. Selenate (Se(VI)) was the dominant species. Silver concentrations ranged between non-detect and 0.11 μg/L. Concentrations and loads of other trace elements were also highly variable and were generally similar to other urban systems with the exceptions of Ag and As (seldom reported) and Cr and Zn which exhibited concentrations and loads in the upper range of those reported elsewhere. Consistent with the semi-arid climatic setting, >95% of suspended sediment, 94% of total Hg, and 85-95 % of all other trace element loads were transported during storm flows with the exception of selenium which showed an inverse relationship between concentration and flow. Treatment of loads is made more challenging in arid climate settings due to low proportions of annual loads and greater dissolved phase during low flow conditions. This dataset fills an important local data gap for highly urban watersheds of San Francisco Bay. The field and interpretative methods, the uniqueness of the analyte list, and resulting information have general applicability for managing pollutant concentrations and loads in urban watersheds in other parts of the world and may have particularly useful application in more arid climates.
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- 2015
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6. Estimation of Contaminant Loads from the Sacramento-San Joaquin River Delta to San Francisco Bay.
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David N, Gluchowski DC, Leatherbarrow JE, Yee D, and McKee LJ
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- Geologic Sediments chemistry, Mercury analysis, Organic Chemicals analysis, San Francisco, Selenium analysis, Bays chemistry, Environmental Monitoring, Rivers chemistry, Water Pollutants, Chemical analysis
- Abstract
Contaminant concentrations from the Sacramento-San Joaquin River watershed were determined in water samples mainly during flood flows in an ongoing effort to describe contaminant loads entering San Francisco Bay, CA, USA. Calculated PCB and total mercury loads during the 6-year observation period ranged between 3.9 and 19 kg/yr and 61 and 410 kg/yr, respectively. Long-term average PCB loads were estimated at 7.7 kg/yr and total mercury loads were estimated at 200 kg/yr. Also monitored were PAHs, PBDEs (two years of data), and dioxins/furans (one year of data) with average loads of 392, 11, and 0.15/0.014 (OCDD/OCDF) kg/yr, respectively. Organochlorine pesticide loads were estimated at 9.9 kg/yr (DDT), 1.6 kg/yr (chlordane), and 2.2 kg/yr (dieldrin). Selenium loads were estimated at 16 300 kg/yr. With the exception of selenium, all average contaminant loads described in the present study were close to or below regulatory load allocations established for North San Francisco Bay.
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- 2015
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7. Polychlorinated biphenyls in the exterior caulk of San Francisco Bay Area buildings, California, USA.
- Author
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Klosterhaus S, McKee LJ, Yee D, Kass JM, and Wong A
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- Bays, California, Spectrometry, X-Ray Emission standards, Construction Materials analysis, Environmental Monitoring, Environmental Pollutants analysis, Polychlorinated Biphenyls analysis
- Abstract
Extensive evidence of the adverse impacts of polychlorinated biphenyls (PCBs) to wildlife, domestic animals, and humans has now been documented for over 40 years. Despite the ban on production and new use of PCBs in the United States in 1979, a number of fish consumption advisories remain in effect, and there remains considerable uncertainty regarding ongoing environmental sources and management alternatives. Using a blind sampling approach, 25 caulk samples were collected from the exterior of ten buildings in the San Francisco Bay Area and analyzed for PCBs using congener-specific gas chromatography-mass spectrometry (GC-MS) and chlorine using portable X-ray fluorescence (XRF). PCBs were detected in 88% of the caulk samples collected from the study area buildings, with 40% exceeding 50 ppm. Detectable PCB concentrations ranged from 1 to 220,000 ppm. These data are consistent with previous studies in other cities that have identified relatively high concentrations of PCBs in concrete and masonry buildings built between 1950 and 1980. Portable XRF was not a good predictor of the PCB content in caulk and the results indicate that portable XRF analysis may only be useful for identifying caulk that contains low concentrations of Cl (≤ 10,000 ppm) and by extension low or no PCBs. A geographic information system-based approach was used to estimate that 10,500 kg of PCBs remain in interior and exterior caulk in buildings located in the study area, which equates to an average of 4.7 kg PCBs per building. The presence of high concentrations in the exterior caulk of currently standing buildings suggests that building caulk may be an ongoing source of PCBs to the San Francisco Bay Area environment. Further studies to expand the currently small international dataset on PCBs in caulking materials in buildings of countries that produced or imported PCBs appear justified in the context of both human health and possible ongoing environmental release., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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8. Reducing methylmercury accumulation in the food webs of San Francisco Bay and its local watersheds.
- Author
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Davis JA, Looker RE, Yee D, Marvin-Di Pasquale M, Grenier JL, Austin CM, McKee LJ, Greenfield BK, Brodberg R, and Blum JD
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- Animals, Environmental Exposure, Humans, Estuaries, Food Chain, Methylmercury Compounds metabolism, Seawater chemistry, Water Pollutants, Chemical metabolism
- Abstract
San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most promising avenues for attempting to reduce methylmercury (MeHg) contamination in Bay Area aquatic food webs and identifying the scientific information that is most urgently needed to support these efforts. Concern for human exposure to MeHg in the region has led to advisories for consumption of sport fish. Striped bass from the Bay have the highest average Hg concentration measured for this species in USA estuaries, and this degree of contamination has been constant for the past 40 years. Similarly, largemouth bass in some Bay Area reservoirs have some of the highest Hg concentrations observed in the entire US. Bay Area wildlife, particularly birds, face potential impacts to reproduction based on Hg concentrations in the tissues of several Bay species. Source control of Hg is one of the primary possible approaches for reducing MeHg accumulation in Bay Area aquatic food webs. Recent findings (particularly Hg isotope measurements) indicate that the decades-long residence time of particle-associated Hg in the Bay is sufficient to allow significant conversion of even the insoluble forms of Hg into MeHg. Past inputs have been thoroughly mixed throughout this shallow and dynamic estuary. The large pool of Hg already present in the ecosystem dominates the fraction converted to MeHg and accumulating in the food web. Consequently, decreasing external Hg inputs can be expected to reduce MeHg in the food web, but it will likely take many decades to centuries before those reductions are achieved. Extensive efforts to reduce loads from the largest Hg mining source (the historic New Almaden mining district) are underway. Hg is spread widely across the urban landscape, but there are a number of key sources, source areas, and pathways that provide opportunities to capture larger quantities of Hg and reduce loads from urban runoff. Atmospheric deposition is a lower priority for source control in the Bay Area due to a combination of a lack of major local sources. Internal net production of MeHg is the dominant source of MeHg that enters the food web. Controlling internal net production is the second primary management approach, and has the potential to reduce food web MeHg in some habitats more effectively and within a much shorter time-frame. Controlling net MeHg production and accumulation in the food web of upstream reservoirs and ponds is very promising due to the many features of these ecosystems that can be manipulated. The most feasible control options in tidal marshes relate to the design of flow patterns and subhabitats in restoration projects. Options for controlling MeHg production in open Bay habitat are limited due primarily to the highly dispersed distribution of Hg throughout the ecosystem. Other changes in these habitats may also have a large influence on food web MeHg, including temperature changes due to global warming, sea level rise, food web alterations due to introduced species and other causes, and changes in sediment supply. Other options for reducing or mitigating exposure and risk include controlling bioaccumulation, cleanup of contaminated sites, and reducing other factors (e.g., habitat availability) that limit at-risk wildlife populations., (Copyright © 2012 Elsevier Inc. All rights reserved.)
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- 2012
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9. A regional mass balance of methylmercury in San Francisco Bay, California, USA.
- Author
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Yee D, McKee LJ, and Oram JJ
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- Chemical Phenomena, Ecological and Environmental Phenomena, Geologic Sediments chemistry, Methylmercury Compounds chemistry, Models, Chemical, San Francisco, Water Pollutants, Chemical chemistry, Environmental Monitoring methods, Methylmercury Compounds analysis, Seawater chemistry, Water Pollutants, Chemical analysis
- Abstract
The San Francisco Bay (California, USA) is a water body listed as impaired because of Hg contamination in sport fish for human consumption, as well as possible effects on resident wildlife. A legacy of Hg mining in local watersheds and Hg used in Au mining in the Sierra Nevada (USA) has contributed to contamination seen in the bay, with additional more recent and ongoing inputs from various sources. Methylmercury is the species of Hg most directly responsible for contamination in biota, so better understanding of its sources, loads, and processes was sought to identify the best means to reduce impacts. A regional scale model of San Francisco Bay was developed to characterize major methylmercury inputs and processes. The model was used to evaluate the potential impact of uncertainties in estimates for methylmercury loading pathways and environmental processes, identify major data gaps, and explore management prospects for reducing methylmercury contamination. External loading pathways considered in the mass balance include methylmercury loads entering via atmospheric deposition to the bay surface, and discharges from the Sacramento/San Joaquin Delta, local watersheds, municipal wastewater, and fringing wetlands. Internal processes considered include exchange between bed and suspended sediments and the water column, in situ production and demethylation, biological uptake, and losses via hydrologic transport to the ocean through the Golden Gate. In situ sediment methylation and demethylation were dominant sources and losses determining ambient steady-state concentrations in the model, with changes in external loads and export causing smaller changes. Better information on methylation and demethylation is thus most critical to improving understanding of methylmercury balances and management., (© 2010 SETAC.)
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- 2011
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10. Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, U.S.A.
- Author
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David N, McKee LJ, Black FJ, Flegal AR, Conaway CH, Schoellhamer DH, and Ganju NK
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- Environmental Monitoring, Geography, Reproducibility of Results, San Francisco, Mercury analysis, Rivers chemistry, Water Pollutants, Chemical analysis
- Abstract
In order to estimate total mercury (HgT) loads entering San Francisco Bay, U.S.A., via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n=78) to suspended sediment concentrations (SSC). During infrequent large floods, HgT concentrations relative to SSC were approximately twice as high as observed during smaller floods. This difference indicates the transport of more Hg-contaminated particles during high discharge events. Daily HgT loads in the Sacramento-San Joaquin River at Mallard Island ranged from below the limit of detection to 35 kg. Annual HgT loads varied from 61 +/- 22 kg (n=5) in water year (WY) 2002 to 470 +/- 170 kg (n=25) in WY 2006. The data collected will assist in understanding the long-term recovery of San Francisco Bay from Hg contamination and in implementing the Hg total maximum daily load, the long-term cleanup plan for Hg in the Bay.
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- 2009
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11. A mass budget of polybrominated diphenyl ethers in San Francisco Bay, CA.
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Oram JJ, McKee LJ, Werme CE, Connor MS, Oros DR, Grace R, and Rodigari F
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- Ethers, Geologic Sediments chemistry, San Francisco, Polybrominated Biphenyls analysis, Water Pollutants, Chemical analysis
- Abstract
A mass budget of polybrominated diphenyl ethers (PBDEs) in San Francisco Bay is developed as a first step towards understanding the local sources and transport processes controlling PBDE fate in a highly urbanized estuary. Extensive monitoring of PBDEs in estuarine water and sediment, freshwater tributaries, air, and wastewater effluents and sludges were integrated with a mass budget model to provide a synthetic view of these emerging contaminants. The Bay inventories of BDE 47 and BDE 209 in 2006 were estimated to be 33+/-3 kg and 153+/-45 kg, respectively. Empirically derived estimates of annual inputs of BDE 47 and BDE 209 from all quantifiable external sources ranged from 11 to 28 kg/y and 22 to 24 kg/y, respectively. BDE 47 loads were dominated by wastewater while runoff from local tributaries represented the largest contributor to BDE 209 loads. Model results suggest the Bay PBDE inventory is highly sensitive to changes in external loads, with degradation and outflow being the major processes governing PBDE fate. The mass budget presented provides a framework for integrating future monitoring and modeling efforts.
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- 2008
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12. Polychlorinated biphenyls (PCBs) in San Francisco Bay.
- Author
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Davis JA, Hetzel F, Oram JJ, and McKee LJ
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- Animals, Animals, Wild metabolism, Environmental Exposure analysis, Humans, Models, Theoretical, Polychlorinated Biphenyls metabolism, Polychlorinated Biphenyls toxicity, Rivers chemistry, San Francisco, Water Pollutants, Chemical metabolism, Water Pollutants, Chemical toxicity, Water Pollution, Chemical legislation & jurisprudence, Water Pollution, Chemical statistics & numerical data, Ecosystem, Polychlorinated Biphenyls analysis, Seawater chemistry, Water Pollutants, Chemical analysis, Water Pollution, Chemical adverse effects
- Abstract
San Francisco Bay is facing a legacy of polychlorinated biphenyls (PCBs) spread widely across the land surface of the watershed, mixed deep into the sediment of the Bay, and contaminating the Bay food web to a degree that poses health risks to humans and wildlife. In response to this persistent problem, water quality managers are establishing a PCB total maximum daily load (TMDL) and implementation plan to accelerate the recovery of the Bay from decades of PCB contamination. This article provides a review of progress made over the past 15 years in managing PCBs and understanding their sources, pathways, fate, and effects in the Bay, and highlights remaining information needs that should be addressed in the next 10 years. The phaseout of PCBs during the 1970s and the 1979 federal ban on sale and production led to gradual declines from the 1970s to the present. However, 25 years after the ban, PCB concentrations in some Bay sport fish today are still more than ten times higher than the threshold of concern for human health. Without further management action it appears that the general recovery of the Bay from PCB contamination will take many more decades. PCB concentrations in sport fish were, along with mercury, a primary cause of a consumption advisory for the Bay and the consequent classification of the Bay as an impaired water body. Several sources of information indicate that PCB concentrations in the Bay may also be high enough to adversely affect wildlife, including rare and endangered species. The greater than 90% reduction in food web contamination needed to meet the targets for protection of human health would likely also generally eliminate risks to wildlife. PCB contamination in the Bay is primarily associated with industrial areas along the shoreline and in local watersheds. Strong spatial gradients in PCB concentrations persist decades after the release of these chemicals to Bay Area waterways. Through the TMDL process, attention is being more sharply focused on the PCB sources that are controllable and contributing most to PCB impairment in the Bay. Urban runoff from local watersheds is a particularly significant pathway for PCB entry into the Bay. Significant loads also enter the Bay through Delta outflow (riverine input). Recent studies have shown that erosion of buried sediment is occurring in large regions of the Bay, posing a significant problem with respect to recovery of the Bay from PCB contamination because the sediments being eroded and remobilized are from relatively contaminated buried sediment deposits. In-Bay contaminated sites are likely also a major contributor of PCBs to the Bay food web. Dredged material disposal, wastewater effluent, and atmospheric deposition are relatively minor pathways for PCB loading to the Bay. Priority information needs at present relate to understanding the sources, magnitude of loads, and effectiveness of management options for urban runoff; the regional influence of in-Bay contaminated sites; remobilization of PCBs from buried sediment; historic and present trends; in situ degradation rates of PCBs; reliable recovery forecasts under different management scenarios; the spatial distribution of PCBs in soils and sediments; and the biological effects of PCBs in interaction with other stressors. The slow release of pollutants from the watershed and the slow response of the Bay to changes in inputs combine to make this ecosystem very slow to recover from pollution of the watershed. The history of PCB contamination in the Bay underscores the importance of preventing persistent, particle-associated pollutants from entering this sensitive ecosystem.
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- 2007
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13. The relationship of clinic experience with advanced HIV and survival of women with AIDS.
- Author
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Laine C, Markson LE, McKee LJ, Hauck WW, Fanning TR, and Turner BJ
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- Acquired Immunodeficiency Syndrome diagnosis, Acquired Immunodeficiency Syndrome prevention & control, Acquired Immunodeficiency Syndrome therapy, Acquired Immunodeficiency Syndrome virology, Delivery of Health Care, Disease Management, Female, Health Personnel, Humans, Medicaid, New York epidemiology, Survival Rate, United States, Acquired Immunodeficiency Syndrome mortality, Ambulatory Care Facilities statistics & numerical data, Outpatient Clinics, Hospital statistics & numerical data, Women's Health Services statistics & numerical data
- Abstract
Objective: Hospital and physician experience have been linked to improved outcomes for persons with HIV. Because many HIV-infected patients receive care in clinics, we studied clinic HIV experience and survival for women with AIDS., Design: Retrospective cohort study of women with AIDS whose dominant sources of care were clinics. Clinic HIV experience was estimated as the cumulative number of Medicaid enrollees with advanced HIV who used a particular clinic as their dominant provider up to the year of the patient's AIDS diagnosis: low experience (< 20 patients), medium (20-99 patients), high (> or = 100 patients). Proportional hazards models examined relationships between experience and survival., Setting: A total of 117 New York State clinics., Patients: A total of 887 New York State Medicaid-enrolled women diagnosed with AIDS in 1989-1992., Main Outcome Measure: Survival after AIDS diagnosis., Results: In later study years (1991-1992), patients in high experience clinics had an approximately 50% reduction in the relative hazard of death (0.53; 95% confidence interval, 0.35-0.82) compared with patients in low experience clinics. Adjusting for demographic and clinical variables, 71% of patients in high experience clinics were alive 21 months after diagnosis compared with 53% in low experience clinics. Experience and survival were not significantly associated in the early study years (1989-1990)., Conclusions: In more recent years, women with AIDS receiving care in high experience clinics survived longer after AIDS diagnosis than those in low experience clinics, providing further evidence of a relationship between provider HIV experience and outcomes.
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- 1998
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14. Two-part survival models applied to administrative data for determining rate of and predictors for maternal-child transmission of HIV.
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Hauck WW, McKee LJ, and Turner BJ
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- Confidence Intervals, Female, Follow-Up Studies, Humans, Infant, Newborn, Logistic Models, Maternal-Fetal Exchange, Medicaid statistics & numerical data, Multivariate Analysis, New York, Nonlinear Dynamics, Pregnancy, Proportional Hazards Models, Survival Analysis, United States, HIV Infections transmission, Infectious Disease Transmission, Vertical statistics & numerical data, Models, Statistical
- Abstract
In analysing maternal-child HIV transmission from Medicaid claims data, we must deal with follow-up that is sometimes so short that we cannot claim that an apparently uninfected infant is actually uninfected as opposed to not yet exhibiting HIV-associated symptoms. To overcome this, we have been using analyses of 'time-to-diagnosis' of HIV infection to estimate transmission rates and predictors of transmission. Such analyses mix the event of transmission with that of our ability to diagnose HIV infection from coded claims data. We would like to separate these two pieces. Also, due to incomplete follow-up, Kaplan-Meier analyses will underestimate transmission rates. In econometrics and biostatistics there are two-part (mixture) models that can serve the goal of separating transmission from the process of diagnosing HIV infection in the newborn. Farewell describes a model that combines a logistic regression for the yes/no event (in our case, HIV transmission) and a Weibull regression model for the survival analysis portion (in our case, time-to-diagnosis). We use this approach to fit models that have potentially separate covariates for transmission and for time-to-diagnosis. The results allow us to identify predictors of transmission and estimate transmission rates with reduced concern for adequacy of follow-up.
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- 1997
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15. Prenatal care and birth outcomes of a cohort of HIV-infected women.
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Turner BJ, McKee LJ, Silverman NS, Hauck WW, Fanning TR, and Markson LE
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- Adult, Birth Weight, Cohort Studies, Female, Gestational Age, Humans, Infant, Low Birth Weight, Infant, Newborn, Infant, Premature, Medicaid, New York, Odds Ratio, Pregnancy, Substance-Related Disorders, United States, HIV Infections, Pregnancy Complications, Infectious, Pregnancy Outcome, Prenatal Care
- Abstract
Adequate prenatal care has been linked to improved birth outcomes in general populations but has not been assessed in HIV-infected women. We examined longitudinal claims files and vital statistics records for women in the New York State Medicaid HIV/AIDS data base delivering a singleton from 1985 through 1990. Adequacy of the self-reported number of prenatal visits was assessed by the Kessner index. In logistics models, we estimated the association of prenatal care, illicit drug use, and other maternal characteristics with three outcomes; low birth weight, preterm birth, and small-for-gestational-age. Of 2,254 singletons delivered by this HIV-infected cohort, 28% were low birth weight, 23% were preterm birth, and 20% were small for gestational age. Two-thirds had inadequate prenatal care. Non-drug users had 57 and 26% lower adjusted odds of low birth weight and preterm delivery than drug users. The adjusted odds of low birth weight and preterm birth for women with an adequate number of prenatal visits were, respectively, 48 and 21% lower than for women with inadequate care. Adequate prenatal care was also associated with a 43% reduction in the odds of small-for-gestational-age. An adequate number of prenatal visits by women in this HIV cohort was associated with a significant reduction in all three adverse birth outcomes, but most had inadequate prenatal care. These data support strengthening efforts to bring pregnant, HIV-infected women into care.
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- 1996
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16. Health care of children and adults with acquired immunodeficiency syndrome. A population-based analysis.
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Turner BJ, Eppes SC, Markson LE, McKee LJ, Fanning TR, and Pantell RH
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- Acquired Immunodeficiency Syndrome mortality, Adolescent, Adult, Age Factors, Ambulatory Care statistics & numerical data, Child, Child, Preschool, Cohort Studies, Emergency Medical Services statistics & numerical data, Female, Hospitalization statistics & numerical data, Humans, Infant, Male, Medicaid, Middle Aged, New York, Population Surveillance, Proportional Hazards Models, Retrospective Studies, United States, Acquired Immunodeficiency Syndrome therapy, Delivery of Health Care statistics & numerical data
- Abstract
Objectives: To compare the use of medical services by pediatric and adult patients with acquired immunodeficiency syndrome (AIDS) in the 6 months before and after the diagnosis of AIDS when demand for care is often high and to study the influence of human immunodeficiency virus specialty care on survival of pediatric patients., Design: Retrospective analysis of Medicaid files., Setting: New York State Medicaid Program., Patients: A cohort identified as having AIDS from 1985 through 1990 and enrolled on Medicaid from birth or 1 year or more before diagnosis. Because of differing prognoses, 3 groups were studied by age at the time that AIDS was diagnosed: infants younger than 6 months, children aged 6 months to 12 years, and adults aged 13 to 60 years., Main Outcome Measures: Frequencies of any service use and, among users, monthly rates of services. From Cox proportional hazards models, the adjusted hazard of death for human immunodeficiency virus specialty ambulatory care., Results: Nearly all infants (n = 122) were hospitalized before and after the diagnosis of AIDS was made--the most of all groups. After diagnosis, only 81% of older children (n = 612) were hospitalized vs 93% of infants and 90% of adults (n = 5602). Hospitalized children had a median of only 3.3 inpatient days per month vs 12.3 and 7.8 inpatient days for infants and adults, respectively. Of older children, 45% used the emergency department vs 33% of adults. Human immunodeficiency virus specialty care for infants and children was associated with a 40% lower risk of death after the diagnosis of AIDS., Conclusions: In this AIDS cohort, infants had the greatest use of inpatient care, and older children used the emergency department more than adults. The finding of improved survival for infants and children with human immunodeficiency virus specialty care warrants further study in more recent years.
- Published
- 1996
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17. Serum immunoreactive-leptin concentrations in normal-weight and obese humans.
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Considine RV, Sinha MK, Heiman ML, Kriauciunas A, Stephens TW, Nyce MR, Ohannesian JP, Marco CC, McKee LJ, and Bauer TL
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- Adipocytes chemistry, Adipose Tissue physiology, Adult, Body Mass Index, Female, Gene Expression, Humans, Leptin, Male, Proteins genetics, RNA, Messenger analysis, Radioimmunoassay, Reference Values, Regression Analysis, Weight Loss physiology, Obesity blood, Proteins analysis
- Abstract
Background: Leptin, the product of the ob gene, is a hormone secreted by adipocytes. Animals with mutations in the ob gene are obese and lose weight when given leptin, but little is known about the physiologic actions of leptin in humans., Methods: Using a newly developed radioimmunoassay, wer measured serum concentrations of leptin in 136 normal-weight subjects and 139 obese subjects (body-mass index, > or = 27.3 for men and > or = 27.8 for women; the body-mass index was defined as the weight in kilograms divided by the square of the height in meters). The measurements were repeated in seven obese subjects after weight loss and during maintenance of the lower weight. The ob messenger RNA (mRNA) content of adipocytes was determined in 27 normal-weight and 27 obese subjects., Results: The mean (+/- SD) serum leptin concentrations were 31.3 +/- 24.1 ng per milliliter in the obese subjects and 7.5 +/- 9.3 ng per milliliter in the normal-weight subjects (P < 0.001). There was a strong positive correlation between serum leptin concentrations and the percentage of body fat (r = 0.85, P < 0.001). The ob mRNA content of adipocytes was about twice as high in the obese subjects as in the normal-weight subjects (P < 0.001) and was correlated with the percentage of body fat (r = 0.68, P < 0.001) in the 54 subjects in whom it was measured. In the seven obese subjects studied after weight loss, both serum leptin concentrations and ob mRNA content of adipocytes declined, but these measures increased again during the maintenance of the lower weight., Conclusions: Serum leptin concentrations are correlated with the percentage of body fat, suggesting that most obese persons are insensitive to endogenous leptin production.
- Published
- 1996
- Full Text
- View/download PDF
18. Selected nutritional and quality analyses of tomatillos (Physalis ixocarpa).
- Author
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Bock MA, Sanchez-Pilcher J, McKee LJ, and Ortiz M
- Subjects
- Dietary Carbohydrates analysis, Dietary Fats analysis, Dietary Fiber analysis, Dietary Proteins analysis, Energy Intake, Hydrogen-Ion Concentration, Nutritive Value, Vegetables chemistry
- Abstract
Proximate composition, total dietary fiber and pH of tomatillos (Physalis ixocarpa) grown in Baja, California were analyzed. Moisture content averaged 92%. On a dry matter basis (DMB), tomatillos contained 11% protein, 18% fat, 13% ash and 5% total dietary fiber. On an as consumed basis (ACB), tomatillos contained 1% protein, 1.5% fat, 1% ash and 0.4% dietary fiber. Carbohydrate (CHO) content was calculated by difference resulting in an average adjusted CHO (excluding dietary fiber) of 53% on a DMB and 4% on an ACB; total CHO (including dietary fiber) was 58 and 4.8%, respectively. Average kcalorie content was calculated to be about 31 kcals/100 g. The average pH of tomatillos was 3.76.
- Published
- 1995
- Full Text
- View/download PDF
19. A population-based comparison of the clinical course of children and adults with AIDS.
- Author
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Turner BJ, Eppes S, McKee LJ, Cosler L, and Markson LE
- Subjects
- AIDS-Related Opportunistic Infections diagnosis, AIDS-Related Opportunistic Infections mortality, Acquired Immunodeficiency Syndrome diagnosis, Acquired Immunodeficiency Syndrome mortality, Adult, Child, Child, Preschool, Disease Progression, Female, Follow-Up Studies, Humans, Infant, Male, New York epidemiology, Pneumonia, Pneumocystis diagnosis, Pneumonia, Pneumocystis mortality, Prognosis, Survival Analysis, Acquired Immunodeficiency Syndrome complications
- Abstract
Objective: To examine the association of clinical complications and age at diagnosis with survival for a cohort of children and adults with AIDS., Design: A population-based analysis of 734 children and 5584 adults diagnosed with AIDS from 1985 to 1990 in New York State., Results: The initial AIDS-defining diagnoses for 68% of children were lymphoid interstitial pneumonitis or infections specified in the Centers for Disease Control and Prevention's (CDC) pediatric AIDS case definition but not the CDC's 1987 adult AIDS case definition. Of opportunistic infections in both case definitions, Pneumocystis carinii pneumonia (PCP) was the most common initial AIDS diagnosis, occurring in 53% of adults, 47% of children aged < 6 months at diagnosis (n = 122) and 14% aged > or = 6 months at diagnosis (n = 612). Median survival after AIDS diagnosis was 62 months for all children compared with 11 months for adults. For children initially diagnosed with conditions only in the pediatric case definition, median survival ranged from 27 to 62 months compared with less than 12 months for children and adults with PCP. Compared with children aged 6-54 months, the estimated hazards of death for younger and older children were 2.06 [95% confidence interval (CI), 1.48-2.86] and 1.54 (95% CI, 1.10-2.16), respectively., Conclusion: Children survived significantly longer than adults after AIDS diagnosis, but their survival varied by age at diagnosis. Differences in the types of common initial AIDS-defining diagnoses appear to contribute to the observed differences in survival.
- Published
- 1995
- Full Text
- View/download PDF
20. Health care delivery, zidovudine use, and survival of women and men with AIDS.
- Author
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Turner BJ, Markson LE, McKee LJ, Houchens R, and Fanning T
- Subjects
- Acquired Immunodeficiency Syndrome complications, Acquired Immunodeficiency Syndrome therapy, Adolescent, Adult, Algorithms, Ambulatory Care statistics & numerical data, Analysis of Variance, Chi-Square Distribution, Cohort Studies, Female, Hospitalization statistics & numerical data, Humans, Longitudinal Studies, Male, Medicaid statistics & numerical data, Middle Aged, New York epidemiology, Pneumonia, Pneumocystis prevention & control, Proportional Hazards Models, Risk Factors, Sex Factors, Substance-Related Disorders complications, Survival Analysis, United States, Acquired Immunodeficiency Syndrome mortality, Delivery of Health Care statistics & numerical data, Zidovudine therapeutic use
- Abstract
The aim of this study was to define predictors of survival for women and men after AIDS diagnosis. We examined health care delivery and drug therapy in the year before AIDS diagnosis for continuously enrolled New York State Medicaid beneficiaries with AIDS in 1988-1990. We examined the association of these factors with survival after AIDS diagnosis. Of 1,077 women and 1,871 men, 60% of both gender groups were drug users. In both risk groups, women had more outpatient visits than men but were equally likely to visit an AIDS specialist. In those who were not drug users, men were twice as likely as women to receive either zidovudine or Pneumocystis carinii pneumonia prophylaxis. No difference appeared among drug users. Survival after AIDS diagnosis was similar by gender for those who were not drug users (RR = 1.09; 95% CI = 0.90-1.33). In drug users, women had a slightly lower risk of death than men (RR = 0.84; 95% CI = 0.72-0.98). Risk of death after AIDS diagnosis was higher for persons starting zidovudine earlier in both risk groups. Among drug users, women received more ambulatory care and survived slightly longer than men. Among those who were not drug users, survival was similar by gender even after adjusting for differences in care.
- Published
- 1994
21. Risk factors for bronchopulmonary dysplasia after extracorporeal membrane oxygenation.
- Author
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Kornhauser MS, Cullen JA, Baumgart S, McKee LJ, Gross GW, and Spitzer AR
- Subjects
- Age Factors, Blood Gas Analysis, Bronchopulmonary Dysplasia diagnostic imaging, Bronchopulmonary Dysplasia therapy, Case-Control Studies, Female, Humans, Infant, Newborn, Intensive Care Units, Neonatal, Logistic Models, Male, Oxygen Inhalation Therapy, Radiography, Respiration, Artificial, Respiratory Insufficiency blood, Respiratory Insufficiency mortality, Risk Factors, Survival Rate, Time Factors, Bronchopulmonary Dysplasia epidemiology, Bronchopulmonary Dysplasia etiology, Extracorporeal Membrane Oxygenation adverse effects, Respiratory Insufficiency therapy
- Abstract
Objective: To determine risk factors for the development of bronchopulmonary dysplasia (BPD) after treatment with extracorporeal membrane oxygenation (ECMO)., Design: Retrospective case-control study., Setting: Tertiary care level 3 neonatal intensive care unit., Participants: Seventy-three newborns treated with ECMO for severe respiratory failure during a 5-year period, who survived until day of life 28, and who did not have pulmonary hypoplasia as the initial cause for respiratory failure., Interventions: None., Main Outcome Measure: The presence of BPD after treatment with ECMO, which was defined as oxygen and/or ventilatory requirements at day of life 28, with characteristic abnormalities seen on chest x-ray film., Results: The age at ECMO initiation was significantly greater for patients with BPD compared with patients without BPD (mean +/- SD, 135 +/- 68 hours vs 50 +/- 37 hours; P < .001). There was an 11.5-fold increased risk for the development of BPD if ECMO was initiated at greater than 96 hours of age. The primary diagnosis of respiratory distress syndrome imparted a 5.2-fold increased risk for the development of BPD. Patients with BPD required ECMO significantly longer than patients without BPD (203 +/- 73 hours vs 122 +/- 51 hours; P < .001)., Conclusion: These results demonstrate that delayed use of ECMO in treating neonatal respiratory failure is associated with an increased risk for the development of BPD and a longer duration of ECMO therapy.
- Published
- 1994
- Full Text
- View/download PDF
22. Body conformation, diet, and risk of breast cancer in pet dogs: a case-control study.
- Author
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Sonnenschein EG, Glickman LT, Goldschmidt MH, and McKee LJ
- Subjects
- Adenocarcinoma etiology, Adenocarcinoma veterinary, Animals, Body Weight, Case-Control Studies, Dogs, Female, Mammary Neoplasms, Animal etiology, Risk Factors, Surveys and Questionnaires, Adenocarcinoma epidemiology, Diet, Dog Diseases epidemiology, Mammary Neoplasms, Animal epidemiology
- Abstract
Canine and human breast cancer share several important clinical and histologic features. A case-control study of nutritional factors and canine breast cancer was conducted at the Veterinary Hospital of the University of Pennsylvania in 1984-1987 by interviewing owners of 150 pet dogs diagnosed with breast cancer, owners of 147 cancer control dogs, and owners of 131 noncancer control dogs. The risk of breast cancer was significantly reduced in dogs spayed at or before 2.5 years of age. Neither a high-fat diet nor obesity 1 year before diagnosis increased the risk of breast cancer according to multiple logistic regression analysis. However, the risk of breast cancer among spayed dogs was significantly reduced in dogs that had been thin at 9-12 months of age (odds ratio (OR) = 0.04 (95% confidence interval (CI) 0.004-0.4) and OR = 0.04 (95% CI 0.004-0.5) for cases vs. cancer controls and cases vs. noncancer controls, respectively, after adjustment for age at spay). Among intact dogs, the risk associated with being thin at 9-12 months of age was reduced, but not significantly so (OR = 0.60 (95% CI 0.2-1.9) and OR = 0.51 (95% CI 0.2-1.4) for the two comparisons, respectively). Results of this study suggest that nutritional factors operating early in life may be of etiologic importance in canine breast cancer.
- Published
- 1991
- Full Text
- View/download PDF
23. Epidemiologic, clinical, pathologic, and prognostic characteristics of splenic hemangiosarcoma and splenic hematoma in dogs: 217 cases (1985).
- Author
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Prymak C, McKee LJ, Goldschmidt MH, and Glickman LT
- Subjects
- Age Factors, Animals, Biopsy veterinary, Dog Diseases pathology, Dogs, Female, Hemangiosarcoma epidemiology, Hemangiosarcoma pathology, Hematoma epidemiology, Hematoma pathology, Male, Pennsylvania, Prognosis, Sex Factors, Splenic Diseases epidemiology, Splenic Diseases pathology, Splenic Neoplasms epidemiology, Splenic Neoplasms pathology, Dog Diseases epidemiology, Hemangiosarcoma veterinary, Hematoma veterinary, Splenic Diseases veterinary, Splenic Neoplasms veterinary
- Abstract
Data on age, sex, and breed were obtained from surgical pathologic records of 92 dogs with splenic hemangiosarcoma (SHS) and for 125 dogs with splenic hematoma (SHA) diagnosed in 1985 at the University of Pennsylvania School of Veterinary Medicine. Further information on body weight, clinical and surgical findings, and survival time was obtained for 59 dogs (64.1%) with SHS and 91 dogs (72.8%) with SHA. Splenic hemangiosarcoma was markedly more common in dogs 8 to 13 years old, and SHA was appreciably more common in dogs greater than or equal to 8 years old, compared with dogs 1 to 7 years old. Compared with sexually intact females, only spayed females were at significantly (odds ratio [or], 2.2; 95% confidence interval [CI], 1.2 to 4.1) increased risk for developing SHS; sex predisposition was not found for dogs with SHA. The German Shepherd Dog was the only breed with increased risk for development of either SHS (OR, 4.7; 95% CI, 2.7 to 7.8) or SHA (OR, 2.8; 95% CI, 1.7 to 4.9), compared with all other purebred dogs. Association of tumor type for 7 commonly reported clinical signs with observance of hemoperitoneum at surgery was determined; anorexia (P = 0.01), collapse (P = 0.01), and hemoperitoneum (P less than 0.001) were significantly more common in dogs with SHS. The median survival time for dogs with SHS was 19 days, compared with 338 days for dogs with SHA (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1988
24. Epidemiologic study of insecticide exposures, obesity, and risk of bladder cancer in household dogs.
- Author
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Glickman LT, Schofer FS, McKee LJ, Reif JS, and Goldschmidt MH
- Subjects
- Administration, Cutaneous, Animals, Animals, Domestic, Carcinoma, Transitional Cell epidemiology, Carcinoma, Transitional Cell etiology, Case-Control Studies, Data Interpretation, Statistical, Dog Diseases etiology, Dogs, Female, Male, Obesity complications, Risk Factors, Tobacco Smoke Pollution adverse effects, Urinary Bladder Neoplasms epidemiology, Urinary Bladder Neoplasms etiology, Carcinoma, Transitional Cell veterinary, Dog Diseases epidemiology, Insecticides adverse effects, Obesity veterinary, Urinary Bladder Neoplasms veterinary
- Abstract
A case-control study of household dogs was conducted to determine if exposure to sidestream cigarette smoke and chemicals in the home, use of topical insecticides, and obesity are associated with the occurrence of bladder cancer. Information was obtained by interview from owners of 59 dogs with transitional-cell carcinoma of the bladder and 71 age- and breed size-matched control dogs with other chronic diseases or neoplasms. Bladder cancer risk was unrelated to sidestream cigarette smoke and household chemical exposures. Risk was significantly increased by topical insecticide use (OR = 1.6 for 1-2 applications per year and OR = 3.5 for greater than 2 applications per year; chi 2 trend; p = .008). This risk was enhanced in overweight or obese dogs. Further studies of this canine model may facilitate identification of specific carcinogens present in insecticides commonly used on pet animals and in the environment.
- Published
- 1989
- Full Text
- View/download PDF
25. Prognostic factors and survival after radiotherapy for intranasal neoplasms in dogs: 70 cases (1974-1985).
- Author
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Evans SM, Goldschmidt M, McKee LJ, and Harvey CE
- Subjects
- Animals, Dog Diseases epidemiology, Dog Diseases surgery, Dogs, Female, Male, Neoplasm Staging veterinary, Nose Neoplasms epidemiology, Nose Neoplasms radiotherapy, Nose Neoplasms surgery, Prognosis, Retrospective Studies, Dog Diseases radiotherapy, Nose Neoplasms veterinary
- Abstract
Survival time and 31 prognostic factors were analyzed for 70 dogs undergoing radiotherapy for intranasal tumors at the Veterinary Hospital of the University of Pennsylvania between 1974 and 1985. At the time of analysis (January 1987), 14.3% (10 of 70) of the dogs were alive. Of the remaining dogs, 34 died because of tumor recurrence, 14 died because of intercurrent disease, and 12 were lost to follow-up evaluation. Pretreatment prognostic factors that were significantly correlated with disease-free interval or long-term survival could not be identified. Notably, presence of a facial mass was not prognostically significant, suggesting that extensive disease should not preclude treatment. Median survival time of dogs with all tumor types was 16.5 months, with a 1-, 2-, and 3-year survival of 54%, 43%, and 35%, respectively. Median survival time of dogs with carcinoma was 13.5 months, with 1-year survival of 51%, 2-year survival of 37%, and 3-year survival of 31%. Orthovoltage radiation was efficacious in the treatment of canine intranasal tumors.
- Published
- 1989
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