Generic physiologically based kinetic modelling for farm animals: Part I. Data collection of physiological parameters in swine, cattle and sheep

Abstract Physiologically based kinetic (PBK) models for farm animals are of growing interest in food and feed safety with key applications for regulated compounds including quantification of tissue concentrations, kinetic parameters and the setting of safe exposure levels on an internal dose basis. The development and application of these models requires data for physiological, anatomical and chemical specific parameters. Here, we present the results of a structured data collection of anatomical and physiological parameters in three key farm animal species (swine, cattle and sheep). We performed an extensive literature search and meta-analyses to quantify intra-species variability and associated uncertainty of the parameters. Parameters were collected for organ weights and blood flows in all available breeds from 110 scientific publications, of which 29, 48 and 33 for cattle, sheep, and swine, respectively. Organ weights were available in literature for all three species. Blood flow parameter values were available for all organs in sheep but were scarcer in swine and cattle. Furthermore, the parameter values showed a large intra-species variation. Overall, the parameter values and associated variability provide reference values which can be used as input for generic PBK models in these species

Physiologically based kinetic models for farm animals: Critical review of published models and future perspectives for their use in chemical risk assessment

Abstract Physiologically based kinetic (PBK) models in the 10 most common species of farm animals were identified through an extensive literature search. This resulted in 39 PBK models, mostly for pharmaceuticals. The models were critically assessed using the WHO criteria for model evaluation, i.e. 1) purpose, 2) structure and mathematical representation, 3) computer implementation, 4) parameterisation, 5) performance, and 6) documentation. Overall, most models were calibrated and validated with published data (92% and 67% respectively) but only a fraction of model codes were published along with the manuscript (28%) and local sensitivity analysis was performed without considering global sensitivity analysis. Hence, the reliability of these PBK models is hard to assess and their potential for use in chemical risk assessment is limited. In a risk assessment context, future PBK models for farm animals should include a more generic and flexible model structure, use input parameters independent on calibration and include assessment tools to assess model performance. Development and application of PBK models for farm animal species would furthermore benefit from the setup of structured databases providing data on physiological and chemical-specific parameters as well as enzyme expression and activities to support the development of species-specific QIVIVE models

Wear and tear of tyres: a stealthy source of microplastics in the environment

Wear and tear from tyres significantly contributes to the flow of (micro-) plastics into the environment. This paper compiles the fragmented knowledge on tyre wear and tear characteristics, amounts of particles emitted, pathways in the environment, and the possible effects on humans. The estimated per capita emission ranges from 0.23 to 4.7 kg/year, with a global average of 0.81 kg/year. The emissions from car tyres (100%) are substantially higher than those of other sources of microplastics, e.g., airplane tyres (2%), artificial turf (12-50%), brake wear (8%) and road markings (5%). Emissions and pathways depend on local factors like road type or sewage systems. The relative contribution of tyre wear and tear to the total global amount of plastics ending up in our oceans is estimated to be 5-10%. In air, 3-7% of the particulate matter (PM2.5) is estimated to consist of tyre wear and tear, indicating that it may contribute to the global health burden of air pollution which has been projected by the World Health Organization (WHO) at 3 million deaths in 2012. The wear and tear also enters our food chain, but further research is needed to assess human health risks. It is concluded here that tyre wear and tear is a stealthy source of microplastics in our environment, which can only be addressed effectively if awareness increases, knowledge gaps on quantities and effects are being closed, and creative technical solutions are being sought. This requires a global effort from all stakeholders; consumers, regulators, industry and researchers alike

An open source physiologically based kinetic model for the chicken (Gallus gallus domesticus): Calibration and validation for the prediction residues in tissues and eggs.

Xenobiotics from anthropogenic and natural origin enter animal feed and human food as regulated compounds, environmental contaminants or as part of components of the diet. After dietary exposure, a chemical is absorbed and distributed systematically to a range of organs and tissues, metabolised, and excreted. Physiologically based kinetic (PBK) models have been developed to estimate internal concentrations from external doses. In this study, a generic multi-compartment PBK model was developed for chicken. The PBK model was implemented for seven compounds (with log Kow range −1.37–6.2) to quantitatively link external dose and internal dose for risk assessment of chemicals. Global sensitivity analysis was performed for a hydrophilic and a lipophilic compound to identify the most sensitive parameters in the PBK model. Model predictions were compared to measured data according to dataset-specific exposure scenarios. Globally, 71% of the model predictions were within a 3-fold change of the measured data for chicken and only 7% of the PBK predictions were outside a 10-fold change. While most model input parameters still rely on in vivo experiments, in vitro data were also used as model input to predict internal concentration of the coccidiostat monensin. Future developments of generic PBK models in chicken and other species of relevance to animal health risk assessment are discussed. Keywords: Risk assessment, Chicken, Physiologically based kinetic model, In vitro to in vivo extrapolation, Global sensitivity analysi

Disentanglement of the chemical, physical, and biological processes aids the development of quantitative structure-biodegradation relationships for aerobic wastewater treatment

Environmental Biolog

Contribución al estudio del comportamiento de las pinturas antiincrustantes

Formulaciones antiincrustantes fueron estudiadas mediante ensayos en balsa de 20 meses de duración,con el fin de establecer la influencia del tipo de inerte utilizado sobre las propiedades tóxicas de la película. Otras variables, tales como el plastificante empleado, la relación colofonia/plastificante, el tipo de tóxico y la relación tóxico/inerte son estudiadas simultáneamente. El empleo de tiza ha proporcionado pinturas cuya eficiencia supera a la de las formulaciones, con óxido férrico y talco; algunas muestras presentan, luego de 375 días de inmersión, un grado de fijación de fouling (0, 0-1 y l)i.gual o inferior al de testigos preparados exclusivamente con pigmentos tóxicos. Dos pinturas, pigmentadas con óxido cuproso —óxido de cinc-tiza cumplen 600 días de inmersión con fijación 1.Antifouling paints were tested in an experimental raft so that to establish the influence of different inert pigments on the toxicity of the film. Some other variables such as the type of plasticizer, the rosin/plasticizer ratio, the type of toxic and the percentage of inert pigment were simultaneously studied. The use of calcium carbonate (chalk) as inert pigment give better performance than other extenders as ferric oxyde or magnesium silicate (talc). Some of that samples show after one year of immersion, lower degree of fixation than paints pigmented with toxics only. Specially two of the paints pigmented with cuprous oxyde-zinc oxyde-chalk still had good performance after 600 days

Extension of the random walk model with an effects module for combined exposure to multiple substances

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Application of probabilistic modelling techniques in human and environmental risk assessment

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