Changes In Contaminant Concentrations Research Articles

Impact of the COVID-19 lockdown on typical ambient air pollutants: Cyclical response to anthropogenic emission reduction

Preliminary studies have confirmed that ambient air pollutant concentrations are significantly influenced by the COVID-19 lockdown measures, but little attention focus on the long term impacts of human countermeasures in cities all over the world during the period. Still, fewer have addressed their other essential properties, especially the cyclical response to concentration reduction. This paper aims to fill the gaps with combined methods of abrupt change test and wavelet analysis, research areas were made of five cities, Wuhan, Changchun, Shanghai, Shenzhen and Chengdu, in China. Abrupt changes in contaminant concentrations commonly occurred in the year prior to the outbreak. The lockdown has almost no effect on the short cycle below 30 d (days) for both pollutants, and a negligible impact on the cycle above 30 d. PM2.5 (fine particulate matter) has a stable short-cycle nature, which is greatly influenced by anthropogenic emissions. The analysis revealed that the sensitivity of PM2.5 to climate is increased along with the concentrations of PM2.5 were decreasing by the times when above the threshold (30–50 μg m−3), and which could lead to PM2.5 advancement relative to the ozone phase over a period of 60 d after the epidemic. These results suggest that the epidemic may have had an impact earlier than when it was known. And significant reductions in anthropogenic emissions have little impact on the cyclic nature of pollutants, but may alter the inter-pollutant phase differences during the study period.

Levels of pesticides and trace metals in water, sediment, and fish of a large, agriculturally-dominated river

Basin land-use interacts with hydrology to deliver chemical contaminants to riverine environments. These chemicals are eventually taken up by aquatic organisms, where they can cause harmful effects. However, knowledge gaps related to the connections between hydrological, chemical, and biological processes currently limit our ability to forecast potential future changes in contaminant concentrations accurately. In this study, concentrations of three pesticide classes (organochlorines, organophosphates, and herbicides) and a standard suite of trace metals were analyzed in the South Saskatchewan River, Canada in 2020 and 2021 in water, sediments, and fishes. Organochlorine pesticides have been banned in Canada since the 1970s, yet there were some detections for methoxychlor and lindane, predominantly in sediment and fish samples, which could be attributed to legacy contamination. Except for malathion and parathion, organophosphate pesticides were scarcely detected in both sampling years in all matrices, and neonicotinoids were below detection in all samples. Conversely, the herbicides 2,4-D and dicamba were detected consistently throughout all locations in water samples for both sampling years. Overall, concentrations were 3 times higher in 2020 when river discharge was ∼2 times higher, suggesting run-off from the surrounding catchment or disturbance of contaminated sediments. Analysis for trace metals revealed that Cu and Zn exceeded sediment quality guidelines in some locations. Mercury concentrations exceeded the guidelines for about 18% of the samples (water and sediment) analyzed. These findings fill gaps in monitoring datasets and highlight key links between hydrology and chemistry that can be further explored in computational models to predict future contaminant trends in freshwater systems.

Implementing a risk-risk analysis framework to evaluate the impact of food intake shifts on risk of illness: a case study with infant cereal

ABSTRACT In food safety, process pathway risk assessments usually estimate the risk of illness from a single hazard and a single food and can inform food safety decisions and consumer advice. To evaluate the health impact of a potential change in diet, we need to understand not only the risk posed by the considered hazard and food but also the risk posed by the substitution food and other potential hazards. We developed a framework to provide decision-makers with a multi-faceted evaluation of the impact of dietary shifts on risk of illness. Our case study explored exposure to inorganic arsenic (iAs) and aflatoxins through consumption of infant cereals and the risk of developing lung, bladder and liver cancer over a lifetime. The estimated additional Disability-Adjusted Life Year (DALY) in the U.S. from exposure to iAs and aflatoxin based on available contamination and consumption patterns of infant rice and oat cereal is 4,921 (CI 90% 414; 9,071). If all infant cereal consumers shift intake (maintaining equivalent serving size and frequency) to only consuming infant rice cereal, the predicted DALY increases to 6,942 (CI 90% 326; 12,931). If all infant cereal consumers shift intake to only consuming infant oat cereal, the predicted DALY decreases to 1,513 (CI 90% 312; 3,356). Changes in contaminant concentrations or percent consumers, that could occur in the future, also significantly impact the predicted risk. Uncertainty in these risk predictions is primarily driven by the dose-response models. A risk-risk analysis framework provides decision-makers with a nuanced understanding of the public health impact of dietary changes and can be applied to other food safety and nutrition questions.

The importance of adjusting contaminant concentrations using environmental data: A retrospective study of 25 years data in Baltic blue mussels

To improve the statistical power of detecting changes in contaminant concentrations over time, it is critical to reduce both the within- and between-year variability by adjusting the data for relevant confounding variables. In this study, we present a method for handling multiple confounding variables in contaminant monitoring. We evaluate the highly variable temporal trends of Polycyclic Aromatic Hydrocarbons (PAHs) in blue mussels from the central Baltic Sea during the period 1987–2016 (data from 25 years during this period) using various regression analyses. As potential explanatory variables related to PAH exposure, we use mussel size and retrospective analyses of mussel δ15N and δ13C (representing large scale biogeochemical changes as a result of e.g. eutrophication and terrestrial inputs). Environmental data from concurrent monitoring programmes (seasonal data on Chlorophyll-a, salinity and temperature in the water column, bioturbation of sediment dwelling fauna) were included as variables related to feeding conditions. The concentrations of high-molecular-weight and low-molecular-weight PAHs in blue mussel were statistically linked to different combinations of environmental variables. Adjustment using these predictors decreased the coefficient of variation in all 15 PAHs tested and improved the statistical power to detect changes. Moreover, the adjustment also resulted in a significant downward trend for fluoranthene that could not be detected initially. For another PAH, benzo(g,h,i)perylene, adjustment which reduced variation resulted in the loss of an apparent downward trend over time. Hence, our study highlights the importance of using auxilliary data to reduce variability caused by environmental factors with general effects on physiology when assessing contaminant time trends. Furthermore, it illustrates the importance of extensive and well designed monitoring programmes to provide relevant data.

Long-term changes in contamination and macrobenthic communities adjacent to McMurdo Station, Antarctica

Improved waste management at McMurdo Station, Antarctica beginning in the 1980s has been followed by decreases in polycyclic aromatic hydrocarbon (PAH) and metal contamination in the adjacent marine sediments. However, determining the effect of the decreased contamination on marine ecological indicators (macrobenthic fauna) is confounded by concurrent changes in climate cycles and other physical forces. Between 2000 and 2013, there was a decrease in concentrations of some contaminants including mercury, copper, organochlorines, and PAHs in marine sediments adjacent to McMurdo Station. PAH concentrations in Winter Quarters Bay decreased an order of magnitude from 2000/2003 to 2012/2013 and were within an order of magnitude of reference area concentrations by 2013. Macrobenthic communities did not indicate any sign of recovery and have not become more similar to reference communities over this same period of time. Temporal changes in macrobenthic community composition during the study period had higher correlations with climatic and sea ice dynamics than with changes in contaminant concentrations. The Interdecadal Pacific Oscillation climatic index had the highest correlation with macrobenthic community composition. The Antarctic Oscillation climatic index, maximum ice extent and other natural environmental factors also appear to influence macrobenthic community composition. Despite large improvements in environmental management at McMurdo Station, continuing environmental vigilance is necessary before any noticeable improvement in ecological systems is likely to occur. The effects of climate must be considered when determining temporal changes in anthropogenic effects in Antarctica. Maintaining long-term monitoring of both contaminants and ecological indicators is important for determining the localized and global influences of humans on Antarctica, which will have implications for the whole planet.

Implementing a Framework to Evaluate the Impact of Food Intake Shifts on Risk of Illness Using a Case Study with Infant Cereal (P11-118-19)

ObjectivesWe developed a framework to provide decision makers with a multi-faceted evaluation of the impact of dietary shifts on risk of illness in the U.S. population. MethodsWe collected representative data on prevalence and concentration of inorganic arsenic and aflatoxin in infant rice and oat cereal. Exposure to these contaminants through consumption and risk of illness from cancer were assessed per consumer based on data from the National Health and Nutrition Examination Survey and published dose-response and related data. The expected number of additional cases of illness and disability-adjusted life years (DALYs) for the U.S. population were estimated. The public health impact of shifts in consumption from one product to the other considered marginal and joint consumption and characterized uncertainty arising from estimates of contaminant concentrations, bioavailability and dose-response models. Monte Carlo simulations were developed in R and a Shiny app was created. ResultsBased on current consumption of infant rice and oat cereal, the estimated additional DALY for the total US population from inorganic arsenic and aflatoxin is 4,600 (CI 90% [370; 8,400]). If all consumers shift their consumption (maintaining equivalent servings) to only infant rice or only infant oat cereal, the estimated DALY increases to 1.4 and decreases to 0.4 relative to the baseline, respectively. Changes in contaminant concentrations or % consumers also significantly impact risk. Uncertainty in risk estimates is primarily driven by the dose-response models for this case study. The case study showcases applicability of the framework for a wide range of food safety and nutrition questions. Results support previous advice on varying grain intake in children. ConclusionsThe current risk-risk framework can provide decision makers with a nuanced understanding of the impact of consumption shifts on public health and reveal parameters that drive predicted changes in public health. The Shiny app provides a real-time visualization tool to facilitate understanding and allow direct query by decision makers. Funding SourcesThis work was carried out under official duties or contract with U.S. FDA.

Time vs. Money: A Quantitative Evaluation of Monitoring Frequency vs. Monitoring Duration.

The National Research Council has estimated that over 126,000 contaminated groundwater sites are unlikely to achieve low ug/L clean-up goals in the foreseeable future. At these sites, cost-effective, long-term monitoring schemes are needed in order to understand the long-term changes in contaminant concentrations. Current monitoring optimization schemes rely on site-specific evaluations to optimize groundwater monitoring frequency. However, when using linear regression to estimate the long-term zero-order or first-order contaminant attenuation rate, the effect of monitoring frequency and monitoring duration on the accuracy and confidence for the estimated attenuation rate is not site-specific. For a fixed number of monitoring events, doubling the time between monitoring events (e.g., changing from quarterly monitoring to semi-annual monitoring) will double the accuracy of estimated attenuation rate. For a fixed monitoring frequency (e.g., semi-annual monitoring), increasing the number of monitoring events by 60% will double the accuracy of the estimated attenuation rate. Combining these two factors, doubling the time between monitoring events (e.g., quarterly monitoring to semi-annual monitoring) while decreasing the total number of monitoring events by 38% will result in no change in the accuracy of the estimated attenuation rate. However, the time required to collect this dataset will increase by 25%. Understanding that the trade-off between monitoring frequency and monitoring duration is not site-specific should simplify the process of optimizing groundwater monitoring frequency at contaminated groundwater sites.

Spatial and temporal trends in brominated flame retardants in seabirds from the Pacific coast of Canada

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) are bioaccumulative flame retardants. PBDEs increased in many ecosystems during the late 20th century, but recently have declined in some environments. To examine trends in the northern Pacific, we analysed PBDEs, HBCDD and carbon and nitrogen stable isotopes (δ13C and δ15N) to account for dietary effects in archived eggs of three seabird species from British Columbia, Canada, 1990–2011 (rhinoceros auklets, Cerorhinca monocerata; Leach's storm-petrels, Oceanodroma leucorhoa; ancient murrelets, Synthliboramphus antiquus, 2009 only). PBDEs increased until approximately 2000 and then decreased, while HBCDD increased exponentially throughout the examined period. No significant changes in dietary tracers were observed. HBCDD and ΣPBDE levels varied among species; ΣPBDE also varied among sites. Temporal changes in contaminant concentrations are unlikely to have been caused by dietary changes, and likely reflect the build-up followed by decreases associated with voluntary phase-outs and regulations implemented in North America to control PBDEs.

Longer-term and short-term variability in pollution of fluvial sediments by dioxin-like and endocrine disruptive compounds

Changes in pollutant loads in relatively dynamic river sediments, which contain very complex mixtures of compounds, can play a crucial role in the fate and effects of pollutants in fluvial ecosystems. The contamination of sediments by bioactive substances can be sensitively assessed by in vitro bioassays. This is the first study that characterizes detailed short- and long-term changes in concentrations of contaminants with several modes of action in river sediments. One-year long monthly study described seasonal and spatial variability of contamination of sediments in a representative industrialized area by dioxin-like and endocrine disruptive chemicals. There were significant seasonal changes in both antiandrogenic and androgenic as well as dioxin-like potential of river sediments, while there were no general seasonal trends in estrogenicity. Aryl hydrocarbon receptor-dependent potency (dioxin-like potency) expressed as biological TCDD-equivalents (BIOTEQ) was in the range of 0.5-17.7 ng/g, dry mass (dm). The greatest BIOTEQ levels in sediments were observed during winter, particularly at locations downstream of the industrial area. Estrogenicity expressed as estradiol equivalents (EEQ) was in the range of 0.02-3.8 ng/g, dm. Antiandrogenicity was detected in all samples, while androgenic potency in the range of 0.7-16.8 ng/g, dm dihydrotestosterone equivalents (DHT-EQ) was found in only 30 % of samples, most often during autumn, when antiandrogenicity was the least. PAHs were predominant contaminants among analyzed pollutants, responsible, on average, for 13-21 % of BIOTEQ. Longer-term changes in concentrations of BIOTEQ corresponded to seasonal fluctuations, whereas for EEQ, the inter-annual changes at some locations were greater than seasonal variability during 1 year. The inter- as well as intra-annual variability in concentrations of both BIOTEQ and EEQ at individual sites was greater in spring than in autumn which was related to hydrological conditions in the river. This study stresses the importance of river hydrology and its seasonal variations in the design of effective sampling campaigns, as well as in the interpretation of any monitoring results.

Ventilation and IAQ in Homes Receiving Energy Efficiency Retrofits

Residential energy efficiency programs in the United States have become increasingly aware of the need to consider the indoor air quality impacts of the energy-based measures that are implemented. This has resulted in a shift from referencing outdated ventilation standards to incorporating ASHRAE Standard 62.2. Because this shift has resulted in substantial concern from program implementers regarding the cost of increased ventilation requirements, research on any benefits of this change is warranted. This presentation provides preliminary data from such a study. This study, which is still underway, implements the older ventilation standard in half of the homes and the current standard in the other half. In all homes, building air leakage reductions are measured before and after retrofit, along with indoor concentrations of a number of common contaminants, including carbon monoxide, carbon dioxide, formaldehyde, total VOCs, radon, and humidity. Existing ventilation is characterized, and additional ventilation to meet the applicable ventilation standard is documented. In addition, health surveys are administered to the occupants before retrofit and a minimum of 6 months after retrofit. This presentation will discuss changes in contaminant concentrations from before to after retrofit, corrected for outdoor weather factors. These changes will be evaluated separately by which of the two ventilation standards was used. Additionally, the total ventilation rates for the two groups will be presented, and the contaminant concentrations will be analyzed based on total ventilation rate, including natural and mechanical sources. Results of the health surveys will not be presented because at this time the sample size of fully completed houses is too small to draw any preliminary conclusions. Because the study is still underway the data presented should not be considered as representing the final conclusions of the study.

In-Situ Combination of Bio and Abio Remediation of Chlorinated Ethenes

Abstract This article deals with combined abio-bioreductive methods for in-situ removal of chlorinated ethenes. The method is based on the use of bioremediation supported by lactate and chemical reduction using nZVI. The method is compared with the use of the individual methods alone, mainly with nZVI. In an environment with very low permeability a poor contaminant removal efficiency was achieved during repeated application of nZVI (about 50% of the original content of contamination). Separate application of lactate resulted in conversion of PCE to 1,2-cis-DCE, whose degradation occurred very slowly. When using the combined abio-bioreductive method, based on consecutive application of lactates and nZVI, over 75% of the original content of contamination was removed. This article discusses not only the changes in concentrations of contaminants but also pH and ORP. Both methods are also compared from an economic point of view.

Assessment of coastal storm impacts on contaminant body burdens of oysters collected from the gulf of Mexico

This study evaluated changes in oyster tissue contaminant levels following North Atlantic tropical cyclones to determine if changes in contaminant concentrations were predictable. The basis for this study was analysis of coastal chemical contaminant data from the National Oceanic and Atmospheric Administration's (NOAA) National Status and Trends Mussel Watch Program and NOAA's National Weather Service storm track data. The tendency for contaminant (metals and organic compounds) body burdens to increase or decrease in oyster tissue after a storm was assessed using contingency and correspondence analyses. Post-storm contaminant levels in oysters revealed a consistent pattern of distribution, which could be described as follows: (1) most of the organic contaminants stay within their long-term concentration ranges, (2) very few organic contaminants decreased, and (3) metals overwhelmingly tend to increase.

Monitoring metal and persistent organic contaminant trends through time using quagga mussels ( Dreissena bugensis) collected from the Niagara River

Historically, the Niagara River received the discharge of persistent bioaccumulative and toxic chemicals from municipal and industrial outfalls and hazardous waste landfills. American and Canadian governments have coordinated investigations of chemicals entering the river and initiated remedial measures and monitoring programs with a goal to reduce loadings of toxic chemicals to the river. This study, a component of the Ontario Ministry of Environment Mussel Biomonitoring Program, compares contaminant concentrations in quagga mussels ( Dreissena bugensis) collected from nine locations in the Niagara River in 1995 and 2003 to assess anticipated changes in tissue concentrations of contaminants in response to ongoing remedial efforts by government agencies and local industries. The concentrations of persistent organic compounds (e.g., PCBs, hexachlorobenzene, hexachlorobutadiene, octachlorostyrene) in quagga mussels in 2003 were lower than concentrations measured in 1995, consistent with a decrease in reported mean annual concentrations of these compounds in water. Significant differences in total PCB concentrations in mussels between stations ( F = 4.6; P < 0.001) suggested sources of PCBs on the American side of the upper Niagara River. In general, highest concentrations of persistent organic compounds were found downstream of the Occidental Chemical Corporation Buffalo Avenue facility suggesting local sources of these contaminants notwithstanding remedial efforts. In contrast, metal concentrations in quagga mussels in 2003 were similar to concentrations found in 1995 and to values reported in the literature for mussels collected from industrialized areas in the Great Lakes. Overall, our results suggest that remedial efforts to improve water quality in the Niagara River have been successful.

High-resolution Electrical Resistivity Tomography monitoring of a tracer test in a confined aquifer

A permanent geoelectrical subsurface imaging system has been installed at a contaminated land site to monitor changes in groundwater quality after the completion of a remediation programme. Since the resistivities of earth materials are sensitive to the presence of contaminants and their break-down products, 4-dimensional resistivity imaging can act as a surrogate monitoring technology for tracking and visualising changes in contaminant concentrations at much higher spatial and temporal resolution than manual intrusive investigations. The test site, a municipal car park built on a former gasworks, had been polluted by a range of polycyclic aromatic hydrocarbons and dissolved phase contaminants. It was designated statutory contaminated land under Part IIA of the UK Environmental Protection Act due to the risk of polluting an underlying minor aquifer. Resistivity monitoring zones were established on the boundaries of the site by installing vertical electrode arrays in purpose-drilled boreholes. After a year of monitoring data had been collected, a tracer test was performed to investigate groundwater flow velocity and to demonstrate rapid volumetric monitoring of natural attenuation processes. A saline tracer was injected into the confined aquifer, and its motion and evolution were visualised directly in high-resolution tomographic images in near real-time. Breakthrough curves were calculated from independent resistivity measurements, and the estimated seepage velocities from the monitoring images and the breakthrough curves were found to be in good agreement with each other and with estimates based on the piezometric gradient and assumed material parameters.

Electrochemical chromic acid regeneration process: fitting of membrane transport properties

A mathematical model was developed to predict changes in contaminant concentrations with time, and to estimate contaminant fluxes due to migration, diffusion, and convection in a laboratory-scale batch electrolysis cell for the regeneration of contaminated hard-chrome plating baths. The feed and extract compartments of the batch-cell were separated by a Nafion-117 diaphragm. The mathematical model was used to estimate process parameters and physical properties of Nafion-117 membrane from experimental results, assuming quasi-stationary operation. Best-fit ionic mobilities of Cu, Fe, and Ni through the Nafion-117 membrane were found to be 5.4, 1.7, and 5.2×10 −10 cm 2/V s, respectively.

Seasonal Dynamics of PCB and Toxaphene Bioaccumulation within a Lake Michigan Food Web

Seasonal variations in PCB and toxaphene concentrations were measured in bulk zooplankton, mysid shrimp, benthic amphipods, alewife, and bloater chub collected from Grand Traverse Bay, Lake Michigan between April and September of 1997 and 1998. Concentrations of PCBs in the dissolved phase of the water column were consistent over time; however, seasonal changes in contaminant concentrations within the biota were significant. Seasonal changes were most pronounced in zooplankton, which displayed highest PCB burdens in April and decreased by as much as 75% through September, coincident with changes in phytoplankton biomass, species composition, and changes in the particulate pools of PCBs within the water column. Mysis sp. display a similar PCB trend as zooplankton, while Diporeia sp. displayed maximal PCB concentrations in late summer during 1997. PCB trends in the primary forage fish alewife ( Alosa pseudoharengus) and bloater ( Coregonus hoyi) were correlated more to shifts in lipid content and seasonal diet preferences. PCB concentrations were higher (p < 0.01) in bloater (310 ± 98 ng/g wet weight) than alewife (233 ± 70 ng/g wet weight), however alewife possessed higher toxaphene burdens (198 ± 72 ng/g wet weight) than bloater (88 ± 36 ng/g wet weight). Alewife contaminant burdens were high in spring and fall of both years, decreasing by as much as 60% in midsummer, and were reflective of changes measured in their lipid content associated with gamete production and spawning. These results suggest that despite invariant concentrations of the dissolved pool of PCBs within the lake, accumulation of PCBs by the biota on seasonal scales is controlled appreciably by growth and lipid dynamics, and foraging behavior.

Removal of As, Mn, Mo, Se, U, V and Zn from groundwater by zero-valent iron in a passive treatment cell: reaction progress modeling

Three treatment cells were operated at a site near Durango, CO. One treatment cell operated for more than 3 years. The treatment cells were used for passive removal of contamination from groundwater at a uranium mill tailings repository site. Zero-valent iron [Fe(0)] that had been powdered, bound with aluminosilicate and molded into plates was used as a reactive material in one treatment cell. The others used granular Fe(0) and steel wool. The treatment cells significantly reduced concentrations of As, Mn, Mo, Se, U, V and Zn in groundwater that flowed through it. Zero-valent iron [Fe(0)], magnetite (Fe 3O 4), calcite (CaCO 3), goethite (FeOOH) and mixtures of contaminant-bearing phases were identified in the solid fraction of one treatment cell. A reaction progress approach was used to model chemical evolution of water chemistry as it reacted with the Fe(0). Precipitation of calcite, ferrous hydroxide [Fe(OH) 2] and ferrous sulfide (FeS) were used to simulate observed changes in major-ion aqueous chemistry. The amount of reaction progress differed for each treatment cell. Changes in contaminant concentrations were consistent with precipitation of reduced oxides (UO 2, V 2O 3), sulfides (As 2S 3, ZnS), iron minerals (FeSe 2, FeMoO 4) and carbonate (MnCO 3). Formation of a free gas phase and precipitation of minerals contributed to loss of hydraulic conductivity in one treatment cell.

Public health response to an incident of secondary chemical contamination at a beach in the United Kingdom

OBJECTIVESTo gather enough data from a large scale investigation involving two health authorities, to assess the possible concentrations and routes of exposure and the consequent health implications.To use the data...

Temporal and Age-Related Trends in Levels of Polychlorinated Biphenyl Congeners and Organochlorine Contaminants in Lake Ontario Lake Trout ( Salvelinus namaycush)

Concentrations of 21 organochlorine contaminants (OCs) and 61 polychlorinated biphenyl (PCB) congeners were determined in archived samples of whole lake trout ( Salvelinus namaycush), age 4 years, collected yearly from eastern Lake Ontario between 1977 and 1993. Temporal trend data show decreases in all parameters analyzed in samples collected from 1977 to 1993. OC levels declined between 60 and 90% from 1977 to 1993. Trends of total PCB and PCB congeners concentrations were variable, but overall levels declined 80% between 1977 and 1993, from 9,060 ng/g in 1,977 to 1,720 ng/g in 1993. Reanalyzed total PCB levels vary randomly from the historical total PCB levels, but overall exhibit a much smoother trend. The means of the two sample sets were not significantly different at a probability of 0.05. Lake trout aged from 3 to 9 years old, collected in 1988, were analyzed to determine changes in contaminant concentrations with age. OC levels on average increased three-fold from 3-year-old lake trout up to 9-year-old lake trout. Total PCB levels increased from 2,760 ng/g in 3-year-old lake trout to 8,000 ng/g in 9-year-old lake trout, and PCB congener concentrations showed similar increases over the same age range. Lipid content declined 30% between 1977 and 1993, but lipid normalizing the data did not change the observed trends.

Organochlorine Contaminants in Common Goldeneye Wintering on the Niagara River

We collected adult male common goldeneye (Bucephala clangula) near their time of arrival on wintering grounds (Nov-Dec) (n = 26) and just prior to spring migration (Feb-Mar) (n = 24) from the Upper Niagara River (UNR), New York, to identify and measure organochlorine contaminants in fat tissues. Detectable concentrations of polychlorinated biphenyl (PCB), dichlorodiphenyldichloroethylene (DDE), dieldrin, hexachlorobenzene (HCB), oxychlordane, and heptachlor epoxide (HE) were found in all adult birds. Polychlorinated biphenyl, dieldrin, HCB, and HE increased (P < 0.05) in adults between the 2 sample periods. In a group of hatching-year (HY) birds sampled in November-December (n = 27), organochlorine residues were less than those of adults from the same period (P < 0.001). Contaminants known to occur in prey items (e.g., crustaceans, gastropods, insects, pelecypods, fish, and annelids) are probably the major source of exposure for common goldeneye on the Niagara River. J. WILDL. MANAGE. 52(3):441-445 The Niagara River is important winter habitat for 15,000-20,000 ducks (Beardslee and Mitchell 1965). Greater scaup (Aythya marila), canvasback (A. valisineria), common merganser (Mergus merganser), red-breasted merganser (M. serrator), oldsquaw (Clangula hyemalis), and common goldeneye are the primary wintering species. Common goldeneye arrive on the Niagara River during late November-early December and stay until mid-March. Their numbers peak at about 3,000 from early January to mid-February (N.Y. State Dep. Environ. Conserv., unpubl. data). Several studies of the Niagara River have found toxic chemicals in water, sediment, benthos, and fish (Yurawecz 1979, Elder et al. 1981, Niagara River Toxics Comm. 1984). Polychlorinated biphenyl, DDE, dichlorodiphenyltrichloroethane (DDT), oxychlordane, and HE have been found in limited numbers of common and red-breasted mergansers, greater scaup, and bufflehead (Bucephala albeola) from the Niagara River (Baker et al. 1976, Kim et al. 1984, N.Y. State Dep. Environ. Conserv. 1984). Organochlorine contaminants from the Niagara River may accumulate to significant levels in wintering common goldeneye because animal foods are important in their diet (Cottam 1939, Stewart 1962, Cronan and Halla 1968). Accumulation of persistent compounds in ducks is a concern to managers of the Niagara River waterfowl resource. From 1974 to 1984, a mean of 988 hunters annually used public blinds on Grand Island (Fig. 1) (N.Y. State Dep. Environ. Conserv., unpubl. data). In addition, comparable hunting pressure occurred on privately owned portions of Grand Island. Humans consuming waterfowl from the Niagara River are exposed to contaminants. The objectives of our study were to identify organochlorine contaminants that occur in common goldeneye wintering on UNR and compare changes in contaminant concentrations in birds from early to late winter. We extend gratitude to B. H. Hohmann, K. N. Williams, D. L. Kiel, M. Kandel, and the cooperating sportsmen whose assistance was essential in completing this study. T. L. Moore, J. R. Snider, and J. R. Colquhoun provided encouragement and advice. An early draft was improved by J. J. Spagnoli, K. F. Wich, G. A. Barnhart, E. G. Horn, and J. Moser. This study was funded through New York's Return a Gift to Wildlife Program, a voluntary contribution program supported by New York taxpayers, and Federal Aid in Fish and Wildlife Restoration