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1.
Emerg Med J ; 41(9): 514-519, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39053972

RESUMEN

BACKGROUND: Older patients living with frailty have an increased risk for adverse events. The Clinical Frailty Scale (CFS) is a 9-point frailty assessment instrument that has shown promise to identify frail emergency department (ED) patients at increased risk of adverse outcomes. The aim of this study was to investigate the association between CFS scores and 30-day mortality in an ED setting when assessments are made by regular ED staff. METHOD: This was a prospective multicentre observational study carried out between May and November 2021 at three EDs in Sweden, where frailty via CFS is routinely assessed by ED staff. All patients ≥65 years of age were eligible for inclusion. Mortality at 7, 30 and 90 days, admission rate, ED and hospital length of stay (LOS) were compared between patients living with frailty (CFS≥5) and robust patients. Logistic regression was used to adjust for confounders. RESULTS: A total of 1840 ED visits of patients aged ≥65 years with CFS assessments done during the study period were analysed, of which 606 (32.9%) were patients living with frailty. Mortality after the index visit was higher in patients living with frailty at 7 days (2.6% vs 0.2%), 30 days (7.9% vs 0.9%) and 90 days (15.5% vs 2.4%). Adjusted ORs for mortality for those with frailty compared with more robust patients were 9.9 (95% CI 2.1 to 46.5) for 7-day, 6.0 (95% CI 3.0 to 12.2) for 30-day and 5.7 (95% CI 3.6 to 9.1) 90-day mortality. Patients living with frailty had higher admission rates, 58% versus 36%, a difference of 22% (95% CI 17% to 26%), longer ED LOS, 5 hours:08 min versus 4 hours:36 min, a difference of 31 min (95% CI 14 to 50), and longer in-hospital LOS, 4.8 days versus 2.7 days, a difference of 2.2 days (95% CI 1.2 to 3.0). CONCLUSION: Patients living with frailty, had significantly higher mortality and admission rates as well as longer ED and in-hospital LOS compared with robust patients. The results confirm the capability of the CFS to risk stratify short-term mortality in older ED patients. TRIAL REGISTRATION NUMBER: NCT04877028.


Asunto(s)
Servicio de Urgencia en Hospital , Fragilidad , Evaluación Geriátrica , Humanos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Servicio de Urgencia en Hospital/organización & administración , Anciano , Suecia/epidemiología , Masculino , Femenino , Estudios Prospectivos , Anciano de 80 o más Años , Evaluación Geriátrica/métodos , Evaluación Geriátrica/estadística & datos numéricos , Fragilidad/mortalidad , Anciano Frágil/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Mortalidad Hospitalaria , Medición de Riesgo/métodos
2.
Brain Behav Immun ; 119: 741-749, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38670241

RESUMEN

Social withdrawal is a well-established part of sickness behavior, but in some contexts sick animals might gain from keeping close instead of keeping away. For instance, sick individuals are more willing to be near known individuals who can provide care and safety (close others) compared to when healthy. Yet, interactions with some strangers might also be beneficial (i.e., healthcare professionals), but it is not known how sickness interplay with social behavior towards such individuals. Here, we assessed if sickness affects perception of caregivers, and developed a new task, the Caregiver Perception Task (CgPT). Twenty-six participants performed the CgPT, once after an injection of lipopolysaccharide (LPS, 0.8 ng/kg body weight, n = 24), and once after an injection of saline (n = 25), one hour and forty-five minutes post-injection. During the task, participants watched short video clips of three types of caregivers: a healthcare professional taking care of a sick individual, a healthcare professional not taking care of a sick individual, and a non-healthcare professional taking care of their sick adult child or partner. After each video clip, the likability, trustworthiness, professionalism, and willingness to interact with and receive care from the caregiver were rated on visual analogue scales. Results showed that participants injected with saline rated healthcare professionals who did not take care of a sick individual less positively on all aspects compared to healthcare professionals who took care of a sick individual. Moreover, compared to saline, LPS increased the participants' willingness to receive care from healthcare professionals and non-healthcare professionals providing care, but not from healthcare professionals not providing care. Thus, our results indicate that sick individuals may approach unknown individuals with potential to provide care and support.


Asunto(s)
Cuidadores , Endotoxemia , Conducta de Enfermedad , Lipopolisacáridos , Humanos , Masculino , Cuidadores/psicología , Femenino , Adulto , Endotoxemia/psicología , Adulto Joven , Percepción/fisiología , Conducta Social
3.
BMC Emerg Med ; 23(1): 124, 2023 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-37880591

RESUMEN

BACKGROUND: The Clinical Frailty Scale (CFS) is a frailty assessment tool used to identify frailty in older patients visiting the emergency department (ED). However, the current understanding of how it is used and accepted in ED clinical practice is limited. This study aimed to assess the feasibility of CFS in an ED setting. METHODS: This was a prospective, mixed methods study conducted in three Swedish EDs where CFS had recently been introduced. We examined the completion rate of CFS assessments in relation to patient- and organisational factors. A survey on staff experience of using CFS was also conducted. All quantitative data were analysed descriptively, while free text comments underwent a qualitative content analysis. RESULTS: A total of 4235 visits were analysed, and CFS assessments were performed in 47%. The completion rate exceeded 50% for patients over the age of 80. Patients with low triage priority were assessed to a low degree (24%). There was a diurnal variation with the highest completion rates seen for arrivals between 6 and 12 a.m. (58%). The survey response rate was 48%. The respondents rated the perceived relevance and the ease of use of the CFS with a median of 5 (IQR 2) on a scale with 7 being the highest. High workload, forgetfulness and critical illness were ranked as the top three barriers to assessment. The qualitative analysis showed that CFS assessments benefit from a clear routine and a sense of apparent relevance to emergency care. CONCLUSION: Most emergency staff perceived CFS as relevant and easy to use, yet far from all older ED patients were assessed. The most common barrier to assessment was high workload. Measures to facilitate use may include clarifying the purpose of the assessment with explicit follow-up actions, as well as formulating a clear routine for the assessment. REGISTRATION: The study was registered on ClinicalTrials.gov 2021-06-18 (identifier: NCT04931472).


Asunto(s)
Fragilidad , Anciano , Humanos , Servicio de Urgencia en Hospital , Fragilidad/diagnóstico , Evaluación Geriátrica/métodos , Estudios Prospectivos , Anciano de 80 o más Años
4.
Integr Environ Assess Manag ; 19(5): 1307-1319, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36562297

RESUMEN

This study presents the development of polychlorinated biphenyl (PCB) background threshold values (BTVs) that statistically characterize ambient background conditions for surface waters in undeveloped and developed landscapes of the Pajarito Plateau in the Rio Grande Basin of New Mexico. Between 2009 and 2018, surface water data were collected at 45 locations under a variety of flow conditions and regimes. A total of 163 samples were collected, with roughly 1/3 of samples and locations being in undeveloped areas (n = 53 from 17 locations), and the remainder being in developed areas (n = 110 from 28 locations). While there are areas on the Pajarito Plateau where PCB point sources are known or likely to have contributed to PCBs in soils, PCB BTVs calculated for undeveloped portions of watersheds (upstream of areas where PCB point sources are known or likely to have contributed to PCBs in soils, and therefore not affected by PCB sources within the watershed) are well above New Mexico's human health organism-only (HH-OO) water quality criterion (0.64 ng/L). Background threshold values are even higher in developed areas upstream of managed soil sites, suggesting that in developed areas, both diffuse ambient PCB sources (e.g., atmospheric deposition) and localized urban sources (e.g., building materials, paints, and electrical equipment) contribute to PCBs in those watersheds. These findings indicate that New Mexico's current HH-OO water quality criterion for PCBs cannot practicably be met due to ambient conditions. It is also impracticable to meet the US Environmental Protection Agency (EPA) criterion continuous concentration (CCC) of 14 ng/L in developed background areas, where the BTV is approximately 1.5 times the CCC. Integr Environ Assess Manag 2023;19:1307-1319. © 2022 SETAC.


Asunto(s)
Bifenilos Policlorados , Humanos , Bifenilos Policlorados/análisis , Monitoreo del Ambiente , New Mexico , Calidad del Agua , Suelo
5.
Integr Environ Assess Manag ; 18(5): 1321-1334, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34664778

RESUMEN

The US Environmental Protection Agency Procedures for the Derivation of Equilibrium Partitioning Sediment Benchmarks (ESBs) for the Protection of Benthic Organisms: Metal Mixtures (Cadmium, Copper, Lead, Nickel, Silver and Zinc) equilibrium partitioning approach causally link metal concentrations and toxicological effects; they apply to sediment and porewater (i.e., interstitial water). The evaluation of bioavailable metal concentrations in porewater, using tools such as the biotic ligand model, provides an advancement that complements sediment-based evaluations. However, porewater characterization is less commonly performed in sediment bioassays than sediment chemistry characterization due to the difficulty and expense of porewater collection as well as concerns about interpretation of porewater data. This study discusses the advantages and disadvantages of different porewater extraction methods for analysis of metals and bioavailability parameters during laboratory sediment bioassays, with a focus on peepers and centrifugation. The purpose is to provide recommendations to generate bioassay porewater data of sufficient quality for use in risk-based decision-making, such as for regulated cleanup actions. Comparisons of paired data from previous bioassay studies indicate that metal porewater concentrations collected via centrifugation tend to be higher than those collected via peepers. However, centrifugation disrupts the redox status of the sediment; also, metal concentrations can vary markedly based on centrifugation conditions. Data to compare the concentrations of peeper- and centrifugation-collected bioavailability parameters (e.g., major ions, pH) are much more limited, but indicate smaller differences than those observed for metal concentrations. While peepers can be sampled without altering the redox status of the porewater, the small volume of porewater peepers collected is enough for metal concentration analysis, but insufficient for analysis of all metal bioavailability parameters. Given the benefits of metal collection via peepers, it is optimal to use centrifugation and peepers in tandem for bioassay porewater collection to improve bioavailability predictions. Environ Assess Manag 2022;18:1321-1334. © 2021 SETAC.


Asunto(s)
Sedimentos Geológicos , Contaminantes Químicos del Agua , Bioensayo , Cobre/análisis , Monitoreo del Ambiente/métodos , Sedimentos Geológicos/química , Metales/análisis , Metales/toxicidad , Contaminantes Químicos del Agua/análisis
6.
Integr Environ Assess Manag ; 18(1): 174-186, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34003570

RESUMEN

US Environmental Protection Agency (USEPA) Procedures for the Derivation of Equilibrium Partitioning Sediment Benchmarks (ESBs) for the Protection of Benthic Organisms: Metal Mixtures are based on the principle that metals toxicity to benthic organisms is determined by bioavailable metals concentrations in porewater. One ESB is based on the difference between simultaneously extracted metal (SEM) and acid volatile sulfide (AVS) concentrations in sediment (excess SEM). The excess SEM ESBs include a lower uncertainty bound, below which most samples (95%) are expected to be "nontoxic" (defined as a bioassay mortality rate ≤24%), and an upper uncertainty bound, above which most samples (95%) are expected to be "toxic" (defined as a mortality rate >24%). Samples that fall between the upper and lower bounds are classified as "uncertain." Excess SEM ESBs can, in principle, be improved by normalizing for organic carbon (OC). OC is a binding phase that reduces metals bioavailability. OC normalization should improve the accuracy of bioavailable metal concentration estimates, thus tightening uncertainty bounds. We evaluated field-collected sediments from 13 studies with excess SEM, OC, and bioassay data (n = 740). Use of the OC-normalized excess SEM benchmarks did not improve prediction accuracy. The ESB model predicts OC-normalized excess SEM exceeding the upper benchmark even when toxicity is not observed, because error in the OC normalization model increases at low OC concentrations. To minimize the likelihood of incorrectly identifying nontoxic samples as toxic, we recommend that OC normalization of excess SEM should not be considered for sediments with an OC concentration <1% and is questionable for sediments with an OC concentration of 1%-4%. Additional focused studies are needed to confirm or refine the minimum sediment OC concentrations that are applicable for reducing uncertainty in toxicity predictions due to excess SEM. Integr Environ Assess Manag 2022;18:174-186. © 2021 SETAC.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Benchmarking , Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/análisis , Estados Unidos , United States Environmental Protection Agency , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
7.
Integr Environ Assess Manag ; 18(5): 1335-1347, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34953029

RESUMEN

The equilibrium partitioning sediment benchmarks (ESBs) derived by the US Environmental Protection Agency (USEPA) in 2005 provide a mechanistic framework for understanding metal bioavailability in sediments by considering equilibrium partitioning (EqP) theory, which predicts that metal bioavailability in sediments is determined largely by partitioning to sediment particles. Factors that favor the partitioning of metals to sediment particles, such as the presence of acid volatile sulfide (AVS) and sediment organic matter, reduce metal bioavailability to benthic organisms. Because ESBs link metal bioavailability to partitioning to particles, they also predict that measuring metals in porewater can lead to a more accurate assessment of bioavailability and toxicity to benthic organisms. At the time of their development, sediment ESBs based on the analysis of porewater metal concentrations were limited to comparison with hardness-dependent metals criteria for the calculation of interstitial water benchmark units (IWBUs). However, the multimetal biotic ligand model (mBLM) provides a more comprehensive assessment of porewater metal concentrations, because it considers factors in addition to hardness, such as pH and dissolved organic carbon, and allows for interactions between metals. To evaluate the utility of the various sediment and porewater ESBs, four Hyalella azteca bioassay studies were identified that included sediment and porewater measurements of metals and porewater bioavailability parameters. Evaluations of excess simultaneously extracted metals, IWBUs, and mBLM toxic units (TUs) were compared among the bioassay studies. For porewater, IWBUs and mBLM TUs were calculated using porewater metal concentrations from samples collected using centrifugation and peepers. The percentage of correct predictions of toxicity was calculated for each benchmark comparison. The mBLM-based assessment using peeper data provided the most accurate predictions for the greatest number of samples among the evaluation methods considered. This evaluation demonstrates the value of porewater-based evaluations in conjunction with sediment chemistry in understanding toxicity observed in bioassay studies. Integr Environ Assess Manag 2022;18:1335-1347. © 2021 SETAC.


Asunto(s)
Sedimentos Geológicos , Contaminantes Químicos del Agua , Benchmarking , Disponibilidad Biológica , Sedimentos Geológicos/química , Ligandos , Metales/análisis , Metales/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
10.
Emerg Med J ; 36(8): 465-471, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31308133

RESUMEN

BACKGROUND: Capillary refill (CR) time is traditionally assessed by 'naked-eye' inspection of the return to original colour of a tissue after blanching pressure. Few studies have addressed intra-observer reliability or used objective quantification techniques to assess time to original colour. This study compares naked-eye assessment with quantified CR (qCR) time using polarisation spectroscopy and examines intra-observer and interobserver agreements in using the naked eye. METHOD: A film of 18 CR tests (shown in a random fixed order) performed in healthy adults was assessed by a convenience sample of 14 doctors, 15 nurses and 19 secretaries (Department of Emergency Medicine, Linköping University, September to November 2017), who were asked to estimate the time to return to colour and characterise it as 'fast', 'normal' or 'slow'. The qCR times and corresponding naked-eye time assessments were compared using the Kruskal-Wallis test. Three videos were shown twice without observers' knowledge to measure intra-observer repeatability. Intra-observer categorical assessments were compared using Cohen's Kappa analysis. Interobserver repeatability was measured and depicted with multiple-observer Bland-Altman plotting. Differences in naked-eye estimation between professions were analysed using ANOVA. RESULTS: Naked-eye assessed CR time and qCR time differ substantially, and agreement for the categorical assessments (naked-eye assessment vs qCR classification) was poor (Cohen's kappa 0.27). Bland-Altman intra-observer repeatability ranged from 6% to 60%. Interobserver agreement was low as shown by the Bland-Altman plotting with a 95% limit of agreement with the mean of ±1.98 s for doctors, ±1.6 s for nurses and ±1.75 s for secretaries. The difference in CR time estimation (in seconds) between professions was not significant. CONCLUSIONS: Our study suggests that naked-eye-assessed CR time shows poor reproducibility, even by the same observers, and differs from an objective measure of CR time.


Asunto(s)
Acción Capilar , Variaciones Dependientes del Observador , Estadística como Asunto/normas , Análisis de Varianza , Competencia Clínica/normas , Competencia Clínica/estadística & datos numéricos , Voluntarios Sanos/estadística & datos numéricos , Hemodinámica/fisiología , Humanos , Reproducibilidad de los Resultados , Estadística como Asunto/métodos , Suecia
12.
J Vis Exp ; (130)2017 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-29286408

RESUMEN

The capillary refill test was introduced in 1947 to help estimate circulatory status in critically ill patients. Guidelines commonly state that refill should occur within 2 s after releasing 5 s of firm pressure (e.g., by the physician's finger) in the normal healthy supine patient. A slower refill time indicates poor skin perfusion, which can be caused by conditions including sepsis, blood loss, hypoperfusion, and hypothermia. Since its introduction, the clinical usefulness of the test has been debated. Advocates point out its feasibility and simplicity and claim that it can indicate changes in vascular status earlier than changes in vital signs such as heart rate. Critics, on the other hand, stress that the lack of standardization in how the test is performed and the highly subjective nature of the naked eye assessment, as well as the test's susceptibility to ambient factors, markedly lowers the clinical value. The aim of the present work is to describe in detail the course of the refill event and to suggest potentially more objective and exact endpoint values for the capillary refill test using diffuse polarization spectroscopy.


Asunto(s)
Capilares/fisiología , Hemodinámica/fisiología , Flujo Sanguíneo Regional/fisiología , Espectrometría Raman/métodos , Humanos
14.
Integr Environ Assess Manag ; 13(6): 1060-1071, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28585730

RESUMEN

Carcinogenic polycyclic aromatic hydrocarbons (cPAHs) are important sediment contaminants that can pose health risks to people who eat shellfish from contaminated sites. Biota-sediment accumulation factors (BSAFs) are quotients of colocated lipid-normalized tissue concentrations and organic carbon (OC)-normalized sediment concentrations, whereas biota-sediment accumulation regressions (BSARs) are models describing the relationships between these tissue and sediment concentrations. BSAR/Fs (BSARs and/or BSAFs) are commonly used to back-calculate sediment preliminary remediation goals (PRGs) from target tissue concentrations; the PRGs are then used to set target action levels (i.e., sediment concentrations above which remedial actions will be prescribed). The cPAH BSAR/Fs reported across sites and species are highly variable due to both site- and species-specific differences and inconsistent BSAR/F calculation methods and assumptions. We reviewed past studies, identified best practices for developing BSAR/Fs, and compiled publicly available colocated tissue and sediment data for 7 cPAHs from 13 sites across the United States. Of the 249 unique cPAH data sets compiled for various species, only 17 yielded acceptable BSAR/Fs, 16 of which were for clams. The influence of BSAR/Fs on sediment remedial action decisions and costs can be disproportionate to the quality of the statistical models from which they are derived. Therefore, it is important to establish and follow best practices for deriving BSAR/Fs and for deciding whether and how BSAR/Fs should be used. Based on our review and analysis, we highlight the advantages of relying on BSARs and propose a consistent method for deriving and judging the reliability of these relationships. We also offer guidance for evaluating the ramifications of BSAR uncertainty on remedial decision making at contaminated sediment sites, and we discuss alternative ways to make risk management decisions in the absence of a reliable site-specific BSAR. Integr Environ Assess Manag 2017;13:1060-1071. © 2017 SETAC.


Asunto(s)
Monitoreo del Ambiente/métodos , Sedimentos Geológicos/análisis , Modelos Teóricos , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Biota , Bivalvos/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Reproducibilidad de los Resultados , Contaminantes Químicos del Agua/metabolismo
16.
Integr Environ Assess Manag ; 10(1): 60-8, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24376109

RESUMEN

This article presents an integrated analysis using a Monte Carlo exposure model, dose­response effects model and habitat,and population dynamics models, all of which allow us to quantitatively estimate the effects of polychlorinated biphenyl (PCB)exposure on American mink (Mustela vison) abundance at the Portland Harbor Superfund Site (Site), and the associated uncertainties. The Site extends from river mile 1.9 of the Lower Willamette River, near its confluence with the Columbia River, to river mile 11.8, just downstream of downtown Portland, Oregon. The potential effects of PCBs on the American mink population were evaluated in the Baseline Ecological Risk Assessment (BERA) due to the historical presence of mink in the are a and because mink are known to be highly sensitive to the effects of PCBs. Hazard quotients (HQs) calculated in the BERA indicated that PCB concentrations measured in Portland Harbor fish were above levels known to cause reproductive effects in mink. Further analysis was needed to evaluate the potential magnitude of effects on the Site mink population. The integrated analysis presented herein demonstrates that if an effect of PCB exposure is a less than 30% reduction in kit production, then PCB remediation is not expected to have any effect on mink abundance. This is a Site­specific conclusion that depends on the quality, abundance, and distribution of mink habitat in Portland Harbor. The PCB dose associated with a 30% reduction in kit production was calculated as 101 mg/kg bw/d (90% CI » 69­146 mg/kg bw/d). The mink PCB dose estimates from the Portland Harbor BERA indicate that if mink are present, their baseline exposure levels probably exceed 101 mg/kg bw/d. Therefore, some level of reduction in PCB exposure could be beneficial to the species if the study area provides sufficient habitat to support a mink population. This analysis demonstrates that risk analysis for population­level assessment endpoints benefits from analyses beyond those that calculate exposure and predict organism­level effects. Evaluation of population­level impacts provides risk managers with a richer perspective within which to evaluate the environmental protectiveness and cost effectiveness of feasibility study alternatives across a range of potential remediation goals.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/toxicidad , Visón/fisiología , Bifenilos Policlorados/toxicidad , Medición de Riesgo/métodos , Animales , Relación Dosis-Respuesta a Droga , Ecosistema , Femenino , Tamaño de la Camada , Masculino , Modelos Estadísticos , Oregon , Dinámica Poblacional
17.
Integr Environ Assess Manag ; 10(1): 102-13, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24105951

RESUMEN

Biota-sediment accumulation factors (BSAFs) and biota-sediment accumulation regressions (BSARs) are statistical models that may be used to estimate tissue chemical concentrations from sediment chemical concentrations or vice versa. Biota-sediment accumulation factors and BSARs are used to fill tissue concentration data gaps, set sediment preliminary remediation goals (PRGs), and make projections about the effectiveness of potential sediment cleanup projects in reducing tissue chemical concentrations. We explored field-based, benthic invertebrate biota-sediment chemical concentration relationships using data from the US Environmental Protection Agency (USEPA) Mid-Continent Ecology Division (MED) BSAF database. Approximately two thirds of the 262 relationships investigated were very poor (r(2) < 0.3 or p-value ≥ 0.05); for some of the biota-sediment relationships that did have a significant nonzero slope (p-value < 0.05), lipid-normalized tissue concentrations tended to decrease as the colocated organic carbon (OC)-normalized sediment concentration increased. Biota-sediment relationships were further evaluated for 3 of the 262 datasets. Biota-sediment accumulation factors, linear regressions, model II regressions, illustrative sediment PRGs, and confidence intervals (CIs) were calculated for each of the three examples. These examples illustrate some basic but important statistical practices that should be followed before selecting a BSAR or BSAF or relying on these simple models of biota-sediment relationships to support consequential management decisions. These practices include the following: one should not assume that the relationship between chemical concentrations in tissue and sediment is necessarily linear, one should not assume the model intercept to be zero, and one should not place too much stock on models that are heavily influenced by one or a few high chemical concentration data points. People will continue to use statistical models of field-based biota-sediment chemical concentration relationships to support sediment investigations and remedial action decisions. However, it should not be assumed that the models will be reliable. In developing and applying BSAFs and BSARs, it is essential that best practices are followed and model limitations and uncertainties are understood, acknowledged, and quantified as much as possible.


Asunto(s)
Bases de Datos Factuales , Sedimentos Geológicos/análisis , Modelos Estadísticos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/farmacocinética , Animales , Biota , Intervalos de Confianza , Invertebrados , Bifenilos Policlorados/análisis , Bifenilos Policlorados/farmacocinética , Análisis de Regresión , Estados Unidos
19.
Integr Environ Assess Manag ; 9(1): 50-62, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22553108

RESUMEN

We assessed population-level risk to upper Arkansas River brown trout (Salmo trutta L.) due to juvenile exposure to Zn. During spring, individuals in the sensitive young-of-the-year life stage are exposed to elevated Zn concentrations from acid mine drainage. We built and used a simple life-history population model for the risk assessment, with survival and fecundity parameter values drawn from published data on brown trout populations located in the United States and Europe. From experimental data, we derived a toxicity model to predict mortality in brown trout fry after chronic exposure to Zn. We tested sensitivity of risk estimates to uncertainties in the life-history parameters. We reached 5 conclusions. First, population projections are highly uncertain. A wide range of estimates for brown trout population growth is consistent with the scientific literature. The low end of this range corresponds to an unsustainable population, a physically unrealistic condition due to combining minimum parameter values from several studies. The upper end of the range corresponds to an annual population growth rate of 281%. Second, excess mortality from Zn exposure is relatively more predictable. Using our exposure-response model for excess mortality to brown trout fry due to Zn exposure in the upper Arkansas River at the mouth of California Gulch in the years 2000 to 2005, we derived a mean estimate of 6.1% excess mortality (90% confidence interval = 1.6%-14.1%). Third, population projections are sensitive to all the parameters that contribute to the onset of reproduction. The weight of evidence suggests that young-of-the-year survival is most important; it is inconclusive about the ranking of other parameters. Fourth, population-level risk from Zn exposure is sensitive to young-of-the-year survival. If young-of-the-year survival exceeds 20% to 25%, then the marginal effect of excess juvenile mortality on population growth is low. The potential effect increases if young-of-the-year survival is less than 20%. Fifth, the effect of Zn on population growth is predictable despite high uncertainty in population projections. The estimate was insensitive to model uncertainties. This work could be useful to ecological risk assessors and managers interested in using population-level endpoints in other risk assessments.


Asunto(s)
Ecotoxicología/métodos , Monitoreo del Ambiente/métodos , Modelos Estadísticos , Ríos/química , Salmonidae , Contaminantes Químicos del Agua/toxicidad , Zinc/toxicidad , Animales , Colorado , Femenino , Medición de Riesgo , Salmonidae/fisiología
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