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Threshold of toxicological concern (TTC) is a concept that has been around for decades in human health sciences. Ecotoxicology recently adopted a variant of this concept as eco-TTC. Adoption of the concept of TTC considerably reduces the amount of animal testing required for regulatory purposes. We provide an application of a universal TTC for the entirety of acute fish toxicity data (i.e., establishment of an exposure level below which there would be minimal probability of acute fish toxicity for any chemical, without consideration of mechanism of action). We calculated TTC values for a number of subgroups using various approaches. These approaches were evaluated using data from a cohort of 69 999 acute fish toxicological assays. This database was normalized/curated for units, exposure duration, quality assurance/control, and duplicates, which reduced it to 47 694 assays. Data were not normally but log-normally distributed, making geometric means the most appropriate statistical parameter. Thus, we developed descriptive statistics using geometric means with 95, 99, and 99.9% confidence intervals. Various assessment factors (akin to predicted-no-effect concentration derivation) were applied to the geometric means to derive TTCs. Other approaches employed were the calculation of y = 0 intercepts as well as development of 95 and 99.75% cutoffs of cumulative data as well as modular uncertainty scoring tool (MUST) analysis. All of the methodologies derived highly congruent TTCs ranging from to 2 to 8 μg/L except for the 99.75th percentile cutoff of 0.3 μg/L. The data would be most useful in making a binary testing/no testing required decision. For acute fish toxicity, a TTC value of 2 μg/L was most appropriate, based on the 95th percentile of data distribution without any assessment factor. Environ Toxicol Chem 2021;40:1740-1749. © 2021 SETAC., (© 2021 SETAC.)

Whether conducting a risk, hazard, or alternatives assessment, one invariably struggles with the task of reconciling multiple available values of toxicological thresholds into a single outcome. When combining multiple pieces of evidence from many different sources, it is important to consider the role of data uncertainty. Uncertainty is inherent to all scientific data. However, in toxicological assessments, controversies and uncertainties are typically understated; they lack methodological transparency; or they poorly integrate qualitative and quantitative sources of information. Similarly, in model development, data curation is rarely performed with sufficient rigor, particularly when applying big data statistics. To overcome the hurdles of a decision process that must reconcile divergent data, we developed an uncertainty scoring tool that can be trained to reproduce specific decision-making paradigms and ensure consistency in the practitioner's judgment across complex scenarios. While designed to aid with ecotoxicological assessments and predictive model development, the tool's applicability extends to any decision-making process that calls for synthesis of incongruent data. Here, we highlight the development process, as well as demonstrate the method's utility in several prototypical ecotoxicological case studies.

Background: Current German legislation ( (section sign) 115 b SGB V) allows groin hernia inpatient treatment only under particular circumstances. That allows the operative technique of first choice for outpatient groin hernia repair to be determined by basic market principles. The aim of this paper was to study the feasibility of outpatient minimally invasive hernia surgery with regard to complication rates, patient satisfaction, and economic considerations., Methods: For 1 year, a total of 571 patients with inguinal hernias (131 male, eight female, mean age 46 years, all ASA I) were treated at two surgical centers. Twenty-four percent (139/571) underwent outpatient total extraperitoneal repair (TEP). Complication rates were recorded. Patient satisfaction with the procedure was evaluated by a standard questionnaire. Cost calculations were compared with revenues according to the EBM2000plus., Results: Of the patients, 96.4% were discharged on the day of operation without subsequent rehospitalization, 84% had no fears of complications at home, 54% went back to work in less than 14 days, and 88.7% were willing to undergo TEP a second time if necessary. Calculated average total cost of euro 709 exceeded the revenue of euro 565 by 20%., Conclusion: For a carefully selected group, outpatient TEP is patient-friendly and safe. Despite these advantages, it still remains economically unattractive to hospital management because of the 20% cover shortage. Improvements in the current legislation are urgently desired.

The toxicity of the mixture NIAX-ESN which contains 95% dimethylaminopropionitrile was evaluated in male rats. Large doses (2.0 ml/kg ip) rapidly produced CNS excitation followed by depression and death. The mixture (given orally as two doses of 0.31 or 0.62 ml/kg respectively) induced acute urinary bladder lesions in 3 days. The changes consisted of massive transmural edema, acute ulcers and inflammation and, occassionally hemorrhagic necrosis of the bladder wall.