Cognitive avoidance and bulimic psychopathology: the relevance of temporal factors in a nonclinical population

OBJECTIVE: Previous research has provided evidence of both an attentional bias towards, and a cognitive avoidance of threat cues, by individuals with unhealthy eating attitudes and disorders. It has been suggested that an initial attentional bias might be followed by a later avoidance process. The present study assessed the speed of processing of self-directed ego threat words following different interstimulus intervals (500, 1,000, 1,500, and 2,000 ms). METHOD: Fifty female students completed a computer-driven threat processing task and the Eating Disorders Inventory. RESULTS: Women were significantly slower to process ego-self threat cues following the 2, 000-ms interval than following the other intervals (500, 1,000, and 1,500 ms). Those women with increased levels of bulimic attitudes were slower to process threats following the 1,500-ms interval, but not after the longer or shorter intervals. CONCLUSIONS: The results stress the importance of temporal factors in the processing of threat by individuals with high levels of eating psychopathology. The findings are discussed in terms of an appropriate cognitive model.     

Occurrence,Spatial Distribution and Health Risk of Hexabromocyclododecane (HBCD) in Source Water in the Lower Yangtze River,China

The occurrence and health risk of hexabromocyclododecane (HBCD), a brominated flame retardant with its three diastereoisomers, in drinking water sources in the lower Yangtze River in China was investigated. Its concentration ranged from 0.58 to 3.71 ng/L and averaged at 1.18 ng/L. Among the three diastereoisomers of α-, β- and γ-HBCD, γ-HBCD was the dominant one accounting for 44% (ranging 27–82%) to the total concentration. Source of HBCD in the contaminated site was discussed according to its spatial distribution and diastereoisomer profile. The margin of exposure (MOE) approach was applied to evaluate the health risk of HBCD through drinking water by estimated exposure and derived reference dose. The MOE was 17 for adults and 12 for children in the worst-case scenario, suggesting a trivial health concern.

     

Spatial and temporal variation in PM(2.5) chemical composition in the United States for health effects studies

BACKGROUND: Although numerous studies have demonstrated links between particulate matter (PM) and adverse health effects, the chemical components of the PM mixture that cause injury are unknown. OBJECTIVES: This work characterizes spatial and temporal variability of PM(2.5) (PM with aerodynamic diameter < 2.5 microm) components in the United States; our objective is to identify components for assessment in epidemiologic studies. METHODS: We constructed a database of 52 PM(2.5) component concentrations for 187 U.S. counties for 2000-2005. First, we describe the challenges inherent to analysis of a national PM(2.5) chemical composition database. Second, we identify components that contribute substantially to and/or co-vary with PM(2.5) total mass. Third, we characterize the seasonal and regional variability of targeted components. RESULTS: Strong seasonal and geographic variations in PM(2.5) chemical composition are identified. Only seven of the 52 components contributed >/= 1% to total mass for yearly or seasonal averages [ammonium (NH(4) (+)), elemental carbon (EC), organic carbon matter (OCM), nitrate (NO(3) (-)), silicon, sodium (Na(+)), and sulfate (SO(4) (2-))]. Strongest correlations with PM(2.5) total mass were with NH(4) (+) (yearly), OCM (especially winter), NO(3) (-) (winter), and SO(4) (2-) (yearly, spring, autumn, and summer), with particularly strong correlations for NH(4) (+) and SO(4) (2-) in summer. Components that co-varied with PM(2.5) total mass, based on daily detrended data, were NH(4) (+), SO(4) (2-) (,) OCM, NO(3) (2-), bromine, and EC. CONCLUSIONS: The subset of identified PM(2.5) components should be investigated further to determine whether their daily variation is associated with daily variation of health indicators, and whether their seasonal and regional patterns can explain the seasonal and regional heterogeneity in PM(10) (PM with aerodynamic diameter < 10 microm) and PM(2.5) health risks.     

Prevalence of obesity and associated risk factors in a Turkish population (trabzon city, Turkey)

OBJECTIVE: To estimate the prevalence of overweight and obesity (general and central) in the Trabzon Region and its associations with demographic factors (age, sex, marital status, reproductive history in women, and level of education), socioeconomic factors (household income and occupation), family history of selected medical conditions (diabetes, hypertension, and obesity), lifestyle factors (smoking habits, physical activity, and alcohol consumption), and hypertension in the adult population. RESEARCH METHODS AND PROCEDURES: A sample of households was systematically selected from the central province of Trabzon and its five towns, namely, Sürmene, Vakfikebir, Ma?ka, Hayrat, and Tonya. A total of 5016 subjects (2728 women and 2288 men) were included in the study. Individuals more than 20 years old were selected from their family health cards. Demographic factors, socioeconomic factors, family history of selected medical conditions, and lifestyle factors were obtained for all participants. Systolic blood pressure and diastolic blood pressure levels were measured for all subjects. Study procedures were carried out in the local health centers in each town over an 8-month period. Obesity was defined as BMI > or = 30 kg/m2 and overweight as BMI = 25.0 to 29.9 kg/m2. RESULTS: The prevalence of obesity was 23.5%: 29.4% in women and 16.5% in men. The combined prevalence of both overweight and obesity was 60.3%. The prevalence of abdominal obesity was 29.4%: 38.9% among women and 18.1% among men. The prevalence of obesity increased with age, being highest in the 60- to 69-year-old age group (40.8%) but lower again in the 70+ age group. Obesity was associated positively with marital status, parity, cessation of cigarette smoking, alcohol consumption, and household income and inversely with level of education, cigarette use, and physical activity. Also, obesity was associated positively with hypertension. DISCUSSION: In the Trabzon Region, 60.3% of the adult population presents with some excess weight. Obesity is a major public health problem that requires generalized interventions to prevent it among the adult population.     

Influence of ecological factors and of land use on mercury levels in fish in the Tapajós River basin, Amazon

Mercury (Hg) contamination of riparian communities and of environmental compartments of the Amazon can be directly related to the occupation of the territory. The objective of this study was to identify the characteristics of aquatic environments that are associated with high levels of Hg in ichthyofauna. Our research aimed at determining the influence of variables related to fish ecology, types of aquatic environment, fishing activities by local riparian populations, and watershed use on the levels of contamination of ichthyofauna. Six sites were sampled during two distinct periods of the hydrological cycle: at the beginning of descending waters and during low waters. We focused on ten dominant fish species representing four trophic levels: Curimata inornata, Geophagus proximus, Schizodon vittatum, Leporinus fasciatus, Anostomoides laticeps, Hemiodus unimaculatus, Caenotropus labyrinthicus, Hoplias malabaricus, Plagioscion squamosissimus, Acestrorhynchus falcirostris. The study sites, which included lotic and lentic habitats, are exploited year-round by local riparian communities. Spatial variations in Hg contamination in ichthyofauna were determined by factorial analysis of variance taking into account fish diets, seasons, and sampling sites. Multiple regressions were used to check the influence of ecological and anthropogenic variables and variables related to watershed uses, on Hg levels in key species representing the four trophic groups. Each variable was checked independently. Next, multiple regressions were used to verify the concomitant influence of selected variables. Independently of the study site and the phase of the hydrologic cycle, fish Hg contamination followed the trend piscivores>omnivores>herbivores>detritivores. In all the aquatic study sites, Hg levels measured in predatory species were often higher than the 500 ng/g fresh weight threshold. Mean Hg levels in key species were significantly higher during descending waters in lotic environments, and during low waters in lentic environments. Data from this study demonstrated that simple models based on watershed use and on easily obtained variables such as the suspended particulate matter (SPM) load and SPM Hg concentrations, number of inhabitants, habitat types, and the stage in the hydrological cycle enable very good prediction of Hg levels in fish. Our cartographical data clearly showed that the watershed site with the highest aquatic vegetation cover (6% of the open water body) and with the lowest forest cover (62% of the land) corresponded to the highest Hg concentrations in fish. Conversely, the watershed site with 94% forest cover and 1% aquatic vegetation corresponded to the lowest levels Hg concentrations in fish. These results suggest that land uses of watersheds play a key role in the level of Hg contamination of local ichthyofauna.     

我国2014-2019年季节性A(H3N2)流感的时空分布特征分析

目的分析我国季节性A(H3N2)[A(H3N2)]亚型流感的时空分布特征, 为流感的科学防控提供参考。方法 2014-2019年A(H3N2)流感监测数据来源于中国流感监测信息系统, 分析和绘制折线图描述流行趋势, 采用ArcGIS 10.7软件进行空间自相关分析, 采用SaTScan 10.1软件进行时空扫描分析。结果 2014年3月31日至2019年3月31日共检测2 603 209例流感样病例标本, A(H3N2)流感检测阳性率为5.96%(155 259/2 603 209)。每个监测年度A(H3N2)流感阳性率在南、北方省份差异均有统计学意义(均P<0.05)。A(H3N2)流感在北方省份冬季高发, 在南方省份夏季或冬季高发。2014-2015年和2016-2017年A(H3N2)流感在31个省份存在空间聚集性。2014-2015年高-高聚集区分布在8个省份(北京市、天津市、河北省、山东省、山西省、河南省、陕西省和宁夏回族自治区);2016-2017年高-高聚集区分布在5个省份(山西省、山东省、河南省、安徽省和上海市)。2014-2019年时空扫描分析结果显示, 201...     

2013—2018年安徽省淮河流域胃癌高危人群内镜筛查参与率及其影响因素分析

目的 研究2013—2018年安徽省淮河流域胃癌高危人群的内镜筛查参与率,探讨可能的影响因素。方法 2013—2018年,在安徽省淮河流域癌症早诊早治项目覆盖的6个地区,采用整群抽样方法,面向40~69岁常住居民,进行健康因素问卷调查和胃癌风险评估,对评估出胃癌高危人群进行内镜筛查,采用χ²检验比较不同特征对象内镜筛查参与率的差异,采用多因素logistic回归模型分析内镜筛查参与率的影响因素。结果 共纳入胃癌高危人群70 927人,其中32 170人接受内镜筛查,总体参与率为45.36%。内镜筛查的参与率存在着显著的时间（χ² = 651.193,P＜0.001）和地区（χ² = 4 799.975,P＜0.001）差异。多因素logistic回归分析显示,女性（OR = 1.27,95%CI:1.22～1.32）、年龄偏大（50～59岁:OR = 1.29,95%CI:1.24～1.34;60～69岁:OR = 1.37,95%CI:1.32～1.43）、大专及以上学历（OR = 1.66,95%CI:1.46～1.90）、离异（OR = 1.43,95%CI:1.27～1.62）、丧偶（OR = 1.12,95%CI:1.03～1.23）、家庭年均收入高（＞10 000～30 000元:OR = 1.46,95%CI:1.41～1.52;＞30 000～50 000元:OR = 1.43,95%CI:1.36～1.50;＞50 000元:OR = 1.24,95%CI:1.16～1.31）、饮用未处理水源（浅表水:OR = 1.33,95%CI:1.27～1.38;深井水/泉水:OR = 1.31,95%CI:1.24～1.37）、不吸烟（OR = 1.27,95%CI:1.21～1.33）、不饮酒（OR = 1.17,95%CI:1.11～1.22）、有消化系统疾病史（1种:OR = 1.32,95%CI:1.27～1.37;2种:OR = 1.93,95%CI:1.81～2.06;3种及以上:OR = 2.47,95%CI:2.17～2.81）和有胃癌家族史（OR = 1.27,95%CI:1.17～1.37）的人群接受内镜筛查参与率较高。结论 胃癌高危人群内镜筛查参与率仍有待提高,研究结果将为今后制定有效的基于人群的胃癌筛查策略提供重要参考。     

Spatial and temporal risk factors for the early detection of Trypanosoma brucei rhodesiense sleeping sickness patients in Tororo and Busia districts, Uganda

We have carried out a study of risk factors for early detection of Trypanosoma brucei rhodesiense sleeping sickness. Records of sleeping sickness patients from 1987 to 2001 from Tororo and Busia districts in Uganda were reviewed for their village of origin and clinical stage (early or late). All villages that reported sleeping sickness and fixed post-diagnostic sleeping sickness health units in Tororo and Busia districts were geo-referenced. The spatial distribution of early and late stage patient detection by health units was analysed using Geographical Information Systems (GIS). Of 1316 sleeping sickness patients admitted at the Livestock Health Research Institute and Busolwe hospitals and Lumino health centre from Tororo and Busia districts, 471 (35.8%) were early stage, 825 (62.7%) were late stage, while 20 (1.5%) were not staged. Five hundred and eighty-five (44.5%) came from within a 10 km radius of the reporting health units. After multivariate analysis, the proportion of early stage patients detected was found to be significantly associated with patients originating from within a 10 km radius of the health unit (P < 0.01), with adults (>19 years) (P < 0.01), and with annual parish incidence (P < 0.01). Application of GIS and the early to late stages ratio are an informative and powerful means of determining efficiency of surveillance of sleeping sickness.     

Genetic diversity and population structure in the Leishmania guyanensis vector Lutzomyia anduzei (Diptera,Psychodidae) from the Brazilian Amazon

Lutzomyia (Nyssomyia) anduzei has been recognized as a secondary vector of Leishmania guyanensis in the Brazilian Amazon region. Since L. anduzei is anthropophilic, co-exists in areas of high leishmaniasis transmission and has been found infected with L. guyanensis, the understanding of the vector population structure and of the process responsible for it is paramount to the vector management and control efforts. In this study we analyzed 74 and 67 sequences of the COI and Cytb loci, respectively, from mitochondrial DNA, aiming to estimate the intra-population genetic variability and population structure in six L. anduzei samples from the Brazilian Amazon region. For COI, we found 58 haplotypes, low to high (F_ST = 0.0310–0.4128) and significant (P = 0.0033) genetic structure, and reduced gene flow among populations. The haplotype network yielded many reticulations that likely resulted from hypervariability in the locus. For Cytb, we observed 27 haplotypes, low to moderate (F_ST = 0.0077–0.1954) and nonsignificant (P > 0.05) genetic structure for the majority of comparisons and extensive gene flow among populations, in line with the haplotypes network data. AMOVA analysis indicated that most of the variation occurred within populations (83.41%, 90.94%); nevertheless, there were significant differences (Φ_ST = 0.0906–0.1659; P = 0.00098; P = 0.00000) among them for both loci. The Mantel test showed that the genetic structure is not associated to an isolation-by-distance (IBD) model in either of both loci. These data suggest that L. anduzei is genetically very diverse. The genetic structure lacking IBD may be due to adaptation to local habitats and the low dispersal capacity of the sandflies, and both could lead to population fragmentation and geographic isolation. These findings have important implications for epidemiology, surveillance and vector control and may be a first step in understanding the evolutionary history of this species.     

渭河流域2005－2015年肾综合征出血热流行特征及环境危险因素分析

目的 了解渭河流域2005－2015年肾综合征出血热（HFRS）流行情况,评估影响HFRS空间分布差异的环境因素。方法 通过“中国疾病预防控制信息系统”收集2005－2015年渭河流域HFRS个案资料,统计描述HFRS流行特征;应用增强回归树模型在5 km×5 km栅格尺度上分析引起疾病地理分布差异的主要因素。结果 2005－2015年,渭河流域共报告HFRS病例18 629例,年均发病率为7.24/10万,2012年HFRS发病率最高,达15.18/10万;HFRS高发区域主要集中在西安市、渭南市等渭河中下游地区;患者年龄集中在16～60岁,但2010年后,>60岁年龄组的发病率超过其他年龄组。增强回归树模型显示区域内建筑用地和农田面积覆盖百分比、海拔高度等因素对HFRS地域分布有较高贡献度。结论 渭河流域HFRS流行特征发生显著变化,>60岁老年人成为发病率最高的人群;建筑用地、农田、海拔高度等环境因素对渭河流域HFRS空间分布发挥着重要影响作用。     

Increasing incidence of malaria in the Negro River basin, Brazilian Amazon

Malaria in Brazil is virtually restricted to the Amazon Region, where it has a heterogeneous geographic distribution. We reviewed secondary data in order to describe the regional and temporal distribution of 8018 malaria cases seen between 2003 and 2007 in Santa Isabel do Rio Negro, a municipality in the northwest Brazilian Amazon. A significant rise in malaria incidence, mainly in the Yanomami Indian reservation, was observed during this time. Anopheline breeding sites were also mapped and entomological data were obtained through the capture of larval and adult mosquitoes. Thirty-three potential breeding sites were identified in the urban and periurban areas, 28 of which were positive for anopheline larvae. Anopheles darlingi specimens were captured in both intra- and peridomicile locations in the urban areas. Demographic data were also assessed via a sectional survey, revealing that the majority of dwellings were vulnerable to mosquitoes. This study suggests that urban and periurban areas of this municipality are highly susceptible to epidemic malaria, which is endemic in the Yanomami Indian reservation near the city. In addition, transmission can be perpetuated autochthonously in the urban area, drawing attention to the continuous need for preventative measures such as controlling adult and aquatic stages of mosquitoes and improving housing.     

Organochlorine chemical residues in fish from the Mississippi River basin, 1995

Fish were collected in late 1995 from 34 National Contaminant Biomonitoring Program (NCBP) stations and 13 National Water Quality Assessment Program (NAWQA) stations in the Mississippi River basin (MRB) and in late 1996 from a reference site in West Virginia. Four composite samples, each comprising (nominally) 10 adult common carp (Cyprinus carpio) or black bass (Micropterus spp.) of the same sex, were collected from each site and analyzed for organochlorine chemical residues by gas chromatography with electron capture detection. At the NCBP stations, which are located on relatively large rivers, concentrations of organochlorine chemical residues were generally lower than when last sampled in the mid-1980s. Residues derived from DDT (primarily p,p′-DDE) were detected at all sites (including the reference site); however, only traces (≤ 0.02 μg/g) of the parent insecticide (p,p′-DDT) were present, which indicates continued weathering of residual DDT from past use. Nevertheless, concentrations of DDT (as p,p′-DDE) in fish from the cotton-farming regions of the lower MRB were great enough to constitute a hazard to fish-eating wildlife and were especially high at the NAWQA sites on the lower-order rivers and streams of the Mississippi embayment. Mirex was detected at only two sites, both in Louisiana, and toxaphene was found exclusively in the lower MRB. Most cyclodiene pesticides (dieldrin, chlordane, and heptachlor epoxide) were more widespread in their distributions, but concentrations were lower than in the 1980s except at a site on the Mississippi River near Memphis, TN. Concentrations were also somewhat elevated at sites in the Corn Belt. Endrin was detected exclusively at the Memphis site. PCB concentrations generally declined, and residues were detected (≥ 0.05 μg/g) at only 35% of the stations, mostly in the more industrialized parts of the MRB. Received: 19 June 2001/Accepted: 19 January 2002     

2015年我国城市空气质量时空特征分析

目的 分析我国城市空气质量的时空分布特征.方法 基于国家环境保护部公布的2015年全国337个城市的逐日空气质量指数(AQI)数据,运用GIS地图、热图及聚类分析等统计手段,分析我国城市空气质量的时空分布特征.结果 我国城市空气质量水平空间差异明显,具有季节特征.AQI大致呈现北高南低的特征,尤其是华北、西北地区AQI最高,华南、华中、西藏及北方部分边境地区AQI较低.AQI冬、春季高于夏、秋季,月峰值普遍出现在1月和12月,新疆塔克拉玛干沙漠地区月峰值出现在3、4月.西北地区首要污染物以PM10为主,华北、华中首要污染物以PM2.5为主.结论 目前我国部分城市空气污染较严重,建议根据城市情况制定不同的空气污染治理策略.     

Spatial and temporal evolution of bluetongue virus in wild ruminants, Spain

We confirmed the emergence of bluetongue virus (BTV) in 5 wild ruminant species in Spain. BTV seroprevalence was high and dispersed with time, with a south-to-north gradient. Our results suggest a complex epidemiology of BTV and underline the need for additional research on wildlife in Europe.     

深圳市一期和二期梅毒时空分布分析

目的 了解深圳市近年来一期和二期梅毒的时空分布特征,为政府财政投入方向和防控措施提供参考.方法 利用深圳市2005-2009年一期和二期梅毒监测数据(n=11 303),以病例中现住址和诊断日期作为地理和时间变量,采用SaTScan软件实现各年的时空扫描分析.结果 单纯时空扫描发现:(1)2005-2009年深圳市梅毒病例集群主要在宝安区和南山交界的南山、南头、新安、西乡,靠近香港的东门、蛇口、福田以及娱乐业比较发达的龙华、华富、黄贝、翠竹等街道,这些聚集区域在2005-2008年变化不大,但是2009年出现了9个新的集群.其中各年最可能的集群分别位于龙华(2005年,P≤0.001,RR=3.34)、翠竹(2006年,P≤0.001,RR=9.59)、华富(2007、2008年,P≤0.001,RR值分别为4.18和4.75)和翠竹(2009年,P≤0.001,RR=8.02).(2)2005-2009年时空重排扫描分析发现16个集群,与单纯空间扫描发现的聚集区域相似但有差异,最可能的集群是2006年的桂园街道.结论 时空分析方法可有效描述疾病聚集,对深圳市近年来一期和二期梅毒监测数据进行时空分析,明确各街道各时段的梅毒变化情况,发现梅毒主要聚集区域,为防治工作提供信息.     

Assessment of current exposure of the population living in the Techa River basin from radioactive releases of the Mayak facility

Current doses arising from external and internal pathways have been estimated for the residents of two villages, Muslumovo and Brodokalmak, alongside the Techa River, which was contaminated by radioactive releases from the Mayak production facility. The dose estimates are based on numerous environmental measurements supplemented by further human whole body measurements and studies on occupational and dietary habits of Slavic and Turkish ethnic groups. Estimated doses arise mainly from use of the contaminated floodplains alongside the Techa River. The current average annual effective dose attributable to Cs and Sr in the environment, under conditions where restrictions on some river-related activities are in place, may exceed the Russian national action level of 1 mSv only in the hypothetical critical group of herdsmen in Muslumovo. The dose to this critical group in Brodokalmak is assessed to be 3 times less than that in Muslumovo and 2 fold below the action level. The external and internal exposures give comparable contributions to the total dose in both settlements and population groups: 47% and 53% in Muslumovo and 40% and 60% in Brodokalmak, respectively. About one quarter to one half of the internal dose in adults arises from the intake of Sr. In order to avoid substantial increases in the dose received by Muslumovo residents, it is expedient to prolong the current policy of restriction of some river-related population activities in this village.     

Spatial and temporal variability of the <Emphasis Type="Italic">Glossina palpalis palpalis</Emphasis>population in the Mbini focus (Equatorial Guinea)

Background  

Human African Trypanosomiasis is a vector-borne parasitic disease. The geographical distribution of the disease is linked to the spatial distribution of the tsetse fly. As part of a control campaign using traps, the spatial and temporal variability is analysed of the glossina populations present in the Mbini sleeping sickness foci (Equatorial Guinea).     

The Swedish Demand-Control-Support Questionnaire (DCSQ): factor structure, item analyses, and internal consistency in a large population

AIM: This paper examined the psychometric properties of the Swedish Demand-Control-Support Questionnaire (DCSQ), which is a shorter and modified version of Karasek's Job Content Questionnaire (JCQ). METHODS: The study encompassed 5,227 workers born in 1953-57 from the population-based Hordaland Health Study. DCSQ, a 17-item questionnaire, covers psychological demands, decision latitude, and social support in the workplace. The workers were manually classified according to the Standard Classification of Occupations. The main statistical methods were principal component analyses, and estimation of internal consistency and the subscales' shared variance by Cronbach's coefficient a and Pearson's correlation coefficients, respectively. RESULTS: The study gave support to the tri-dimensional factor structure of DCSQ. Decision latitude tended to split into skill discretion and decision authority in skill-level homogeneous samples. The specificity of the item loadings was satisfactory except for "conflicting demands". The inter-correlation of the three main subscales was weak. The internal consistency of the subscales was generally satisfactory. CONCLUSIONS: The psychometric properties of DCSQ are satisfactory. Being shorter and easier to use than the more comprehensive JCQ, DCSQ represents an important alternative, particularly if respondent burden and data-collection costs need to be minimized.     

Exposure and effects assessment of resident mink (Mustela vison) exposed to polychlorinated dibenzofurans and other dioxin-like compounds in the Tittabawassee River basin, Midland, Michigan, USA

Historically, sediments and floodplain soils of the Tittabawassee River (TR; MI, USA) have been contaminated with polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated biphenyls (PCBs). Median concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) based on 2006 World Health Organization tetrachlorodibenzo-p-dioxin toxic equivalency factors (TEFs) in the diet of mink (Mustela vison) ranged from 6.8 x 10(-1) ng TEQ/kg wet weight upstream of the primary source of PCDF to 3.1 x 10(1) ng TEQ/kg wet weight downstream. Estimates of toxicity reference values (TRVs) derived from laboratory studies with individual PCDDs/PCDFs and PCB congeners or mixtures of those congeners, as well as application of TEFs, were compared to site-specific measures of mink exposure. Hazard quotients based on exposures expressed as concentrations of TEQs in the 95th percentile of the mink diet or liver and the no-observable-adverse-effect TRVs were determined to be 1.7 and 8.6, respectively. The resident mink survey, however, including number of mink present, morphological measures, sex ratios, population age structure, and gross and histological tissue examination, indicated no observable adverse effects. This resulted for multiple reasons: First, the exposure estimate was conservative, and second, the predominantly PCDF congener mixture present in the TR appeared to be less potent than predicted from TEQs based on dose-response comparisons. Given this, there appears to be great uncertainty in comparing the measured concentrations of TEQs at this site to TRVs derived from different congeners or congener mixtures. Based on the lack of negative outcomes for any measurement endpoints examined, including jaw lesions, a sentinel indicator of possible adverse effects, and direct measures of effects on individual mink and their population, it was concluded that current concentrations of PCDDs/PCDFs were not causing adverse effects on resident mink of the TR.