Lower Confidence Limit Research Articles

A whole system approach to improving mortality associated with acute kidney injury.

Acute kidney injury (AKI) is in the main managed by non-nephrologists, many who feel challenged by or lack awareness of the complexity that the renal element adds to their patients' care. National reports have raised major concerns about the quality of care and have predicted that mortality reductions of 30% are achievable with good medical practice. This quality improvement project evaluated whether a whole system approach could improve outcomes for patients with AKI. Quality improvement methodology was used to understand hospital patterns, processes and professional knowledge. Change concepts were developed which included management of patients at risk, staff education and awareness program, development of a patient specific electronic alert to prompt diagnosis, easy to remember care bundle (ABCDE-IT), dedicated outreach team and patient and family empowerment leaflet. Statistical process control analysis was used to verify outcomes over time. A shift in the in-hospital mortality rate corresponded to a relative 23.2% reduction in mortality and was sustained over the next 33 months (P < 0.0001). The favourable shift in mortality was temporally distinct from the improved AKI detection rate. This timeframe corresponded to lying below the 99.8% lower confidence limit in comparison with all English acute trusts for comparative AKI specific SHMI/HSMR mortality rates. Length of stay also reduced shortly after onset of the project by 14.1% or 2.6 day reduction (P < 0.0001). This project demonstrated that an integrated, whole-system approach is necessary to ensure sustained improvements in AKI mortality and length of stay.

A national survey of tetrabromobisphenol-A, hexabromocyclododecane and decabrominated diphenyl ether in human milk from China: Occurrence and exposure assessment

A national survey of three currently used brominated flame retardants (BFRs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) and decabrominated diphenyl ether (BDE-209) in human milk was conducted in 2011. Human milk from 16 provinces of China were collected, pooled and measured. The estimated daily intake (EDI) via human milk ingestion for nursing infant and the related health risks were evaluated. The median levels of TBBPA, HBCD and BDE-209 were 1.21, 6.83 and 0.556ng/g lipid weight (lw), respectively. Levels of BDE-209 were lower than those of TBBPA, indicating that the production and application of deca-BDE in China has been below that of TBBPA after the restriction of PBDEs. Moreover, contamination levels of TBBPA and HBCD in this survey were higher than those observed in last national survey conducted in 2007, indicating an increase of TBBPA and HBCD in the environment from 2007 to 2011. The mean estimated daily intakes (EDIs) of TBBPA, HBCD and BDE-209 via human milk for 1–6months old infant were 39.2, 51.7 and 3.65ng/kgbw/day, respectively. For risk assessment, margin of exposure (MOE) was calculated by comparing the BMDL10 (benchmark dose lower confidence limit for a benchmark response of 10%) to the EDI of each BFR. Large MOEs indicates that the estimated dietary exposure to these three BFRs for nursing infant is unlikely to raise significant health concerns. Compared with some currently used novel BFRs which also measured in this survey, higher contamination levels were found in some non-PBDE BFRs, indicating that the consumption pattern of BFRs has shifted from PBDEs to non-PBDE BFRs in China.

Exact inference for exponential distribution with multiply Type-I censored data

ABSTRACTIn this paper, we focus on exact inference for exponential distribution under multiple Type-I censoring, which is a general form of Type-I censoring and represents that the units are terminated at different times. The maximum likelihood estimate of mean parameter is calculated. Further, the distribution of maximum likelihood estimate is derived and it yields an exact lower confidence limit for the mean parameter. Based on a simulation study, we conclude that the exact limit outperforms the bootstrap limit in terms of the coverage probability and average limit. Finally, a real dataset is analyzed for illustration.

Analysis on the estimation errors of the lowest and highest astronomical tides for the southwestern 2.5 GW offshore wind farm, Korea

For the design of wind-power facilities, the highest and lowest astronomical tides (HAT and LAT, respectively) are needed for the tidal-water levels regarding international designs; however, the approximate highest high water and approximate lowest low water AHHW and ALLW, respectively, have been used in Korea. The HAT and LAT in the wind-farm test-bed sea should be estimated to satisfy the international standard. In this study, the HAT and LAT are therefore estimated using the hourly tidal-elevation data of the Eocheongdo, Anmado, Younggwang, Gunsan, Janghang, and Seocheon tidal-gauging stations that are located in the adjacent coastal sea. The nodal variation patterns of the major lunar components, such as M2, O1, and K1 are analyzed to check the expected long-term lunar cycle, i.e., 18.61 year's nodal-variation patterns. The temporal amplitude variations of the M2, O1, and K1 clearly show the 18.61-years periodic patterns in the case of the no-nodal correction condition. In addition, the suggested HAT and LAT elevations, estimated as the upper and lower confidence limits of the yearly HAT and LAT elevations, are 50 cm greater than the AHHW and 40 cm lower than the ALLW, respectively.

Dietary exposure to acrylamide from cafeteria foods in Jeddah schools and associated risk assessment.

Acrylamide (AA) is a carcinogenic and genotoxic food contaminant produced at high temperatures in foods that are rich in carbohydrates. Foods sold in schools in Jeddah, Saudi Arabia, are among such carbohydrate-rich foods produced at high cooking temperatures. It is crucial to determine the importance of AA exposure with respect to cafeteria foods and assess the associated risks. The highest mean AA level was measured in chocolate pies (439 µg kg-1 ), followed by custard pies (435 µg kg-1 ) and cheese pies (432 µg kg-1 ). The average and 95th percentile values of AA exposure were 0.51 and 1.17 [µg kg-1 body weight (BW) school day-1 ]. The average exposure significantly decreased with an increase in age, from 0.65 (µg kg-1 BW school day-1 ) in primary school students to 0.37 in secondary school students. Cheese and chocolate pies are the main contributors in AA intake. The contributions of cheese and chocolate pies to the average exposure among primary, middle and secondary school students were 23.1%, 24.7% and 29.4% and 16.9%, 12.1% and 11.9%, respectively. Other products with significant contributions included cheese sandwiches (10.8%, 8.9% and 12.7%), plain cookies (7.7%, 5.6% and 6.7%) and custard pies (7.7%, 4.8% and 8.9%). Other cafeteria products contributed to AA exposure at much lower percentages. The calculated margins of exposure (MOEs) for the average [356 and 614 for both benchmark dose lower confidence limit (BMDL) 0.18 and 0.31 mg kg-1 BW day-1 ] and 95th percentile AA exposure values (154 and 265 for both BMDL 0.18 and 0.31 mg kg-1 BW day-1 ) suggest that there is a health concern with respect to school-aged students. © 2017 Society of Chemical Industry.

Red blood cells derived from whole blood treated with riboflavin and ultraviolet light maintain adequate survival in vivo after 21 days of storage.

Pathogen reduction (PR) of whole blood (WB) may increase blood safety when applied before component separation. This study evaluates the in vivo performance of red blood cells (RBCs) derived from WB treated with the riboflavin and ultraviolet (UV) light PR (Mirasol) system. This was a prospective, two-center, single-blind, randomized, two-period, crossover clinical trial designed to evaluate autologous 51 Cr/99m Tc-radiolabeled recovery and survival of RBCs derived from Mirasol-treated WB compared to untreated WB. RBCs were stored in AS-3 for 21 days at 1 to 6°C. In vitro RBC variables were characterized. Frequency and severity of treatment-emergent adverse event (TEAE) and neoantigenicity were determined. Twenty-four healthy adult volunteers (n=12 per site) were evaluated. The Mirasol 24-hr RBC recoveries were 82.5±3.9% with one-sided 95% lower confidence limit of 80.9%, meeting US Food and Drug Administration acceptance criteria, albeit at lower level than controls (91.7±6.8%, p<0.001). Mean RBC survival and T50 were reduced in the Mirasol group (61 and 23 days, respectively) versus controls (82 and 36 days, respectively; p<0.001) with a mean area under the curve survival of treated RBCs of 83% of untreated controls. End-of-storage hemolysis in the Mirasol group was 0.22±0.1% (control, 0.15±0.1%; p<0.001). No neoantigenicity or differences in TEAEs were found. RBCs derived from Mirasol WB and stored for up to 21 days in AS-3 maintained acceptable cell quality and recovery, albeit modestly reduced compared with untreated RBCs. Mirasol WB may represent a valid single WB PR platform that allows manufacture of RBC for storage for up to 21 days.

Activity of cyclosporine&lt;sup&gt;®&lt;/sup&gt; against &lt;i&gt;Schistosoma mansoni&lt;/i&gt; cercariae

Schistosomiasis is a helminth disease that affect many people all over the world causing illnesses there by preventing people from farming and performing other activities, and at times gives rise to malignancies which could be fatal. Despite the successes of treatment of schistosomiasis by paraziquantel and some aspects of molluscicides, the disease remains one of the most important public health problems in many developing countries including Nigeria. This study attempted to interrupt the life cycle at the cercarial stage through administration of cyclosporine to halt the reoccurrence of infection. Snail intermediate host (Biomphalaria pfeifferi)were obtained from the stream (Farin Gada, Jos, Plateau State), examined for cercariae by exposure to sunshine for 30 minutes andcercariae obtained were estimated using Neubauer’s counting chamber before toxicity test was conducted. The schistosomicidal properties of cyclosporine were tested invitro against Schistosoma mansoni cercariae. A stock solution of 6.13 mg/L was obtained after a range finding test from which serial dilutions were made to obtain concentrations of 3.06, 2.06, 1.06 and 0.06 mg/L respectively while the control had no test drug (0.00 mg/L). Each of these concentrations was applied in duplicate replication to 10 ml of water containing 15 freshly shed cercariae. Viability of the cercariae were monitored at different time intervals. Data obtained was subjected to regression analysis to find line of best fit. The cercariae percentage mortalities were calculated and transformed into probit mortality and the 12 hour LC50 and 95% confidence limits were determined. The 12hr LC50 was calculated to be 1.08 mg/L with 95% upper and lower confidence limits as 2.08 and 0.53mg/L respectively while the LT50 was calculated to be 2.75 hours. The result revealed a strong and positive correlation (r2 = 0.59) between the concentration of cyclosporine and probit mortality value which indicates strong larvicidal effects against the cercariae. The result also revealed potential anticercarial activities of cyclosporine based on the acute toxicity concentration (LC50) and the lethal time (LT50) on S.mansoni cercariae which would rekindle public health interest for the need to curb the risk of reinfection being a major problem of schistosomiasis management globally.Keywords: B. pffeiferi; S. mansoni; cercariae; cyclosporine; anticercarial.

Development of biomonitoring equivalents for barium in urine and plasma for interpreting human biomonitoring data

The objectives of the present work were: (1) to assemble population-level biomonitoring data to identify the concentrations of urinary and plasma barium across the general population; and (2) to derive biomonitoring equivalents (BEs) for barium in urine and plasma in order to facilitate the interpretation of barium concentrations in the biological matrices. In population level biomonitoring studies, barium has been measured in urine in the U.S. (NHANES study), but no such data on plasma barium levels were identified. The BE values for plasma and urine were derived from U.S. EPA's reference dose (RfD) of 0.2 mg/kg bw/d, based on a lower confidence limit on the benchmark dose (BMDL05) of 63 mg/kg bw/d. The plasma BE (9 μg Ba/L) was derived by regression analysis of the near-steady-state plasma concentrations associated with the administered doses in animals exposed to barium chloride dihydrate in drinking water for 2-years in a NTP study. Using a human urinary excretion fraction of 0.023, a BE for urinary barium (0.19 mg/L or 0.25 mg/g creatinine) was derived for US EPA's RfD. The median and the 95th percentile barium urine concentrations of the general population in U.S. are below the BE determined in this study, indicating that the population exposure to inorganic barium is expected to be below the exposure guidance value of 0.2 mg/kg bw/d.

Confidence limits for system reliability indices with increasing function of failure intensity

The problem of calculating the lower confidence limit for the reliability function and the other main indices, such as the mean time to failure (mean lifetime) and the guaranteed (gamma-percentile) lifetime of a system based on the reliability test results has been considered. The problem is solved under the general nonparametric assumption of the monotonically increasing failure intensity function (aging) of a system. A series of expressions for the lower confidence limits of the aforementioned main reliability indices has been derived.

Estimating reliability of redundant system from the results of testing its elements

Consideration was given to the problem of constructing the lower confidence limit for the probability of failsafe system operation (reliability function) from the results of testing its elements. Solution of this problem was obtained for a rather general case of system elements ageing with monotone increasing function of failure rate. In case where the system can be redundantized both by identical and different-type elements, approximate asymptotic expressions were established for the case of high reliability.

Arsenic speciation in rice consumed in south-western Nigeria, and estimation of dietary intake of arsenic species through rice consumption

ABSTRACTThis study determined concentrations and speciation of arsenic (As) in rice samples obtained from the cities of Akure, Ore, Ondo and Ikare in Ondo State, south-western Nigeria. The estimated dietary intake of As from rice consumption for total As and the identified As species were compared with the As benchmark dose lower confidence limit. Analyses of rice from the four cities identified three As species: inorganic As, monomethylarsonic, acid and dimethylarsinic acid. Concentrations of total As and the As species differed significantly across the sampling locations (by a factor of 2.5 for total As). Mean levels (±S.D.) were 58.8 ± 0.7 µg/kg total As, 47.0 ± 0.6 µg/kg inorganic As, 0.33 ± 0.03 µg/kg monomethylarsonic acid, and 11.5 ± 0.1 µg/kg dimethylarsinic acid. The estimated mean dietary intakes were 4.1 µg/d total As, 3.3 µg/d inorganic As, 0.02 µg/d monomethylarsonic acid, and 0.8 µg/d dimethylarsinic acid. These values are below the benchmark dose lower confidence limit and comparable to, or lower than, those reported for other countries. Thus, consumption of rice cultivated in south-western Nigeria does not appear to have inherent As-associated health risks.

A novel approach to deriving the lower confidence limit of indices Cpu, Cpl, and Cpk in assessing process capability

Process capability indices (PCIs) are widely used as a measure of process potential and process performance. Unfortunately, the use of sample data to estimate PCIs means that any error in the sampling can introduce considerable uncertainty into the assessment of process capability. This necessitates the use of the lower confidence limit (LCL) in the estimation of minimum process capability. Furthermore, the complexity of sampling distributions of the PCIs greatly hinders interval estimation, such that only an approximate or asymptotic LCL can be achieved. This paper proposes a novel approach to deriving the LCL of indices Cpu, Cpl and Cpk using Boole’s inequality and DeMorgan’s theorem. This approach is based on subsample data collected from a stable process. Hypothesis testing is also used to determine whether the process is capable of satisfying the quality requirements of customers. We calculated the critical values of the PCIs for various significance levels, capability requirements and sample sizes. Finally, we present analysis of two cases to demonstrate the applicability of the proposed approach.

Immunogenicity assay cut point determination using nonparametric tolerance limit

The newly released FDA guidance on immunogenicity assay development and validation recommends use of a lower confidence limit of the percentile of the negative subject population as the cut point in order to guarantee a pre-specified false positive rate with high confidence. The limit is, in essence, a lower tolerance limit. Although in literature several methods are available for determining the tolerance limit, they either fail to take into account the repeated measurement of the data from a typical immunogenicity assay quantification/validation experiment or rely heavily on normality assumption of the data, which is rarely correct. As a result, the methods may result in biased estimates of the cut point, causing the false positive rate to be either lower or higher than expected. To overcome this drawback, we propose two non-parametric methods under repeated measure data structure and without normal distribution assumption. Simulation studies were carried to compare the performance of the two non-parametric approaches with the current methods. The results of the simulation studies show that one of the two nonparametric methods outperforms all the other methods and provides a satisfactory coverage probability even with moderate sample sizes. In addition, it is simple and straightforward to implement. Therefore, it is a preferred method for immunogenicity assay cut point determination.

Estimation of Benchmark Dose of Lifetime Cadmium Intake for Adverse Renal Effects Using Hybrid Approach in Inhabitants of an Environmentally Exposed River Basin in Japan.

The aim of this study is to estimate the reference level of lifetime cadmium intake (LCd) as the benchmark doses (BMDs) and their 95% lower confidence limits (BMDLs) for various renal effects by applying a hybrid approach. The participants comprised 3,013 (1,362 men and 1,651 women) and 278 (129 men and 149 women) inhabitants of the Cd-polluted and nonpolluted areas, respectively, in the environmentally exposed Kakehashi River basin. Glucose, protein, aminonitrogen, metallothionein, and β2 -microglobulin in urine were measured as indicators of renal dysfunction. The BMD and BMDL that corresponded to an additional risk of 5% were calculated with background risk at zero exposure set at 5%. The obtained BMDLs of LCd were 3.7 g (glucose), 3.2 g (protein), 3.7 g (aminonitrogen), 1.7 g (metallothionein), and 1.8 g (β2 -microglobulin) in men and 2.9 g (glucose), 2.5 g (protein), 2.0 g (aminonitrogen), 1.6 g (metallothionein), and 1.3 g (β2 -microglobulin) in women. The lowest BMDL was 1.7 g (metallothionein) and 1.3 g (β2 -microglobulin) in men and women, respectively. The lowest BMDL of LCd (1.3 g) was somewhat lower than the representative threshold LCd (2.0 g) calculated in the previous studies. The obtained BMDLs may contribute to further discussion on the health risk assessment of cadmium exposure.

Bioequivalence of generic and branded amoxicillin capsules in healthy human volunteers.

CONTEXT:The Medical Council of India urges doctors to prescribe generic drugs as far as possible. The Indian Medical Association had responded earlier saying that it requires guarantees on the quality of generic forms of drugs. Although no published scientific reports are available on the issue of therapeutic inequivalence, unconfirmed clinician accounts and newspaper reports of therapeutic inequivalence exist.AIM:This study was planned to ascertain whether bioequivalence of branded and generic amoxicillin capsule is comparable.SETTINGS AND DESIGN:An open-label, randomized, single-dose, two-treatment, two-sequence, two-period crossover oral bioequivalence study was conducted in 12 healthy, adult human subjects under fasting condition.MATERIALS AND METHODS:Serum samples, collected at 8 time points, were analyzed by a validated ultraviolet spectrophotometer method. Pharmacokinetic (PK) parameters such as area under the curve (AUC)0–t, AUC0–∞, Cmax, and Tmax were determined along with time above minimum inhibitory concentration (MIC).STATISTICAL ANALYSIS USED:The log-transformed PK parameters (Cmax, AUC0–t, AUC0–∞) were analyzed using a Two One-Sided Test ANOVA in SAS for each parameter. Tmax and MIC were analyzed by Wilcoxon rank-sum test in GraphPad Prism.RESULTS:Geometric mean ratio of Cmax fell within bioequivalence criteria. The upper and lower confidence limits of both AUC0–t and AUC0–∞ geometric mean ratio fell below bioequivalence criteria. Time above MIC of generic preparation was significantly lower than that of branded version.CONCLUSIONS:The generic capsule was not bioequivalent to the branded amoxicillin capsule.

Safe time duration for temporary middle cerebral artery occlusion in aneurysm surgery based on motor-evoked potential monitoring.

Background:Temporary vessel occlusion of the parent artery is an essential technique for aneurysm surgery. Our aim was to clarify the safe time for temporary occlusion for aneurysm surgery, that is the “safe time duration” (STD), in which brain tissue exposed to ischemia will almost never fall into even the ischemic penumbra during temporary occlusion of the middle cerebral artery (MCA), and even transient postoperative motor impairment will be rare using intraoperative motor-evoked potentials (MEP).Methods:Twenty-four patients underwent MCA aneurysm clipping surgery with MEP monitoring for 13 ruptured aneurysms and 11 unruptured aneurysms. The duration of vessel occlusion in patients without MEP changes was measured as the STD. Average STD was calculated as 95% confidence interval for the population mean using sample data from patients with MEP changes and patients without changes.Results:All 24 patients received proximal flow control only. Five patients (20.8%) developed significant intraoperative MEP changes. Time to MEP change (i.e., STD) in these patients was 4.6 ± 2.1 min. In patients without MEP changes, STD was 2.7 ± 1.4 min. Average STD was thus 3.1 ± 0.7 min.Conclusions:The 95% lower confidence limit for average STD was 2.4 min when applying temporary occlusion on the proximal side of the MCA. This STD resembled that previously reported for temporary proximal occlusion of the internal carotid artery.

Identifying the third dimension in 2D fluoroscopy to create 3D cardiac maps.

Three-dimensional cardiac mapping is important for optimal visualization of the heart during cardiac ablation for the treatment of certain arrhythmias. However, many hospitals and clinics worldwide cannot afford the high cost of the current mapping systems. We set out to determine if, using predefined algorithms, comparable 3D cardiac maps could be created by a new device that relies on data generated from single-plane fluoroscopy and patient recording and monitoring systems, without the need for costly equipment, infrastructure changes, or specialized catheters. The study included phantom and animal experiments to compare the prototype test device, Navik 3D, with the existing CARTO 3 System. The primary endpoint directly compared: (a) the 3D distance between the Navik 3D-simulated ablation location and the back-projected ground truth location of the pacing and mapping catheter electrode, and (b) the same distance for CARTO. The study's primary objective was considered met if the 95% confidence lower limit was greater than 0.75% for the Navik 3D-CARTO difference between the 2 distances, or less than or equal to 2 mm. Study results showed that the Navik 3D performance was equivalent to the CARTO system, and that accurate 3D cardiac maps can be created using data from equipment that already exists in all electrophysiology labs.

Anthelmintic resistance status of gastrointestinal nematodes of sheep to the single or combined administration of benzimidazoles and closantel in three localities in Mexico

Veterinaria Mexico OA ISSN: 2448-6760 Cite this as: Alcala Canto Y, Sumano Lopez HS, Ocampo Camberos L, Gutierrez L. Anthelmintic resistance status of gastrointestinal nematodes of sheep to the single or combined administration of benzimidazoles and closantel in three localities in Mexico. Veterinaria Mexico OA. 2016;3(4). doi: 10.21753/vmoa.3.4.374 Sheep production requires the constant assessment of parasitic burden and the efficacy of existing treatments for proper management. In this study, the administration of five different treatments was evaluated for the reduction of the percentage of eggs per gram of feces (EPG) shed by gastrointestinal nematodes (GIN) from sheep on three different sheep-breeding farms in Mexico (Texcoco, Estado de Mexico; Hueytamalco, Puebla; and Tlaltizapan de Zapata, Morelos). In these farms, ivermectin and benzimidazole derivatives had been routinely administered for two consecutive years. To determine whether drugs with different pharmacological properties decreased GIN fecal egg excretion, the treatments closantel (CLOS), albendazole (ABZ) and fenbendazole (FBZ) were administered alone and in combinations of CLOS + ABZ and CLOS + FBZ, to five groups of sheep, with an additional untreated control group on each farm (n = 28 per flock). Anthelmintic resistance was determined using Fecal Egg Count Reduction Tests (FECRT) as recommended in the guidelines of the World Association for the Advancement of Veterinary Parasitology. Fecal samples were collected 14 and 21 days after treatment. The anthelmintic resistance status was determined based on the reduction in the fecal egg count arithmetic mean and 95 % confidence limits. According to the FECRT, resistance developed to CLOS, ABZ, FBZ and CLOS + FBZ because the mean percentage of EPG reduction was ≤ 95 % with a lower confidence limit of ≤ 90 %. By contrast, nematode susceptibility was confirmed for the CLOS + ABZ combination, as it reduced the percentage of GIN fecal egg output by 96.46 ± 3.04 % (day 14) and 96.88 ± 3.04 % (day 21). Based on the morphometric identification of larvae, Haemonchus spp., Cooperia spp. and Teladorsagia spp. were the most abundant genera on all farms before the administration of these five treatments. In conclusion, the use of the anthelmintic combination of closantel plus albendazole may reduce the development of anthelmintic resistance in gastrointestinal nematodes. Figure 1. Marginal means ± SD of the percentage reduction in egg count on days 14 and 21 after treatment of sheep on three farms (n = 28 per flock) with fenbendazole (FBZ), closantel (CLOS), albendazole (ABZ), closantel + fenbendazole (CLOS + FBZ) and closantel + albendazole (CLOS + ABZ).

Dietary exposure to trace elements and health risk assessment in the region of Valencia, Spain: a total diet study

ABSTRACTDietary exposure of the Valencian region population to lead, cadmium, inorganic arsenic (iAs), chromium, copper, tin and methylmercury (meHg) was assessed in a total diet study carried out in the region of Valencia in 2010–11. A total of 8100 food samples were collected and analysed. Occurrence data were combined with consumption data to estimate dietary exposure in adults (> 15 years of age) and young children (6–15 years of age). The estimated intake was calculated by a probabilistic approach. Average intake levels (optimistic scenario) for lead, iAs, chromium and tin were 0.21, 0.08, 1.79 and 1.87 µg kg−1 bw day−1 respectively; for Cd and meHg average intake levels were 0.77 and 0.54 µg kg–1 bw week−1, respectively, and for Cu, 1.60 mg day−1. In terms of risk characterisation, the results showed that 2.84% of the adult population may exceed the BMDL10 (benchmark dose lower confidence limit) established for Pb, which is linked to renal effects; whereas 28.01% of the young children population may exceed the BMDL01 related to neurodevelopment effects. In addition, 8.47% of the adult population and 12.32% of young children exceeded the meHg tolerable weekly intake (TWI).

Human health impacts of exposure to metals through extreme consumption of fish from the Colombian Caribbean Sea.

The health risks of metal exposure due to the high consumption of fish were assessed for a riverine population living on the Caribbean coast of Colombia. The concentrations of metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the edible tissues of fish were determined and used for risk assessment. The daily fish consumption of residents (n=95) was as high as 283, 366 and 469g/day in children (CH), women of childbearing age (WCHA) and the remaining population groups (RP), respectively. The estimation of the potential risk (HQ) indicated that there was no health risk from most of the metals, because they did not exceed their related reference doses, with values of HQ<1. Although the concentrations of Pb and Hg were not particularly high in fish (<0.2µg/g), their possible health effects for vulnerable groups are of great concern due to the extremely high fish intake. The Pb intake for all groups was higher than the lower confidence limit of the benchmark dose for nephrotoxicity and neurodevelopmental effects in children. The weekly intake of methylmercury was also elevated, with values approximately 3, 2 and 1.5 times the provisional tolerable weekly intake for CH, WCHA and RP, respectively. Moreover, higher Hg levels were found in top predators, whereas maximum levels for other metals were found in bottom-feeding fish. This study highlights that an accurate data of daily intake, a continuous monitoring of metals in fish and their related fish consumption advisories to protect subsistence fishing communities are recommended in a local and worldwide context.