Biokinetics and biokinetic models in risk assessment

1996 ◽  
Vol 15 (10) ◽  
pp. 799-809 ◽  
Author(s):  
PW van Vliet ◽  
J. de Jongh
Keyword(s):  
Risk Assessment ◽  
Animal Species ◽  
Animal Data ◽  
The Subject ◽  
Risk Of Exposure ◽  
Route Of Exposure ◽  
High Doses ◽  
General Aspects

Risk assessment ofxenobiotics using animal data involves extrapolation from high doses to low ones, and from animal species to humans. In some cases it also involves extrapolation from one route of exposure to another. To assess the risk of exposure to xenobiotics, information on both biokinetics and biodynamics are needed. The contribution of biokinetics to risk assessment is the subject of this review. The review includes the general aspects of biokinetics of chemicals, the models available to describe the biokinetic behaviour of a chemical and a discussion of the class of biokinetic models that is considered most suited for application to risk assessment: the physiologi cally-based biokinetic (PBBK) models. The power of PBBK models is illustrated with a few examples.

scholarly journals High risk of respiratory diseases in children in the fire period in Western Amazon

2016 ◽  
Vol 50 (0) ◽  
Author(s):  
Pãmela Rodrigues de Souza Silva ◽  
Eliane Ignotti ◽  
Beatriz Fátima Alves de Oliveira ◽  
Washington Leite Junger ◽  
Fernando Morais ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Monte Carlo Simulation ◽  
Respiratory Diseases ◽  
Fine Particulate Matter ◽  
Fine Particulate ◽  
Risk Of Exposure ◽  
Toxicological Risk ◽  
High Doses ◽  
Toxicological Risk Assessment ◽  
Medium Potential

ABSTRACT OBJECTIVE To analyze the toxicological risk of exposure to ozone (O3) and fine particulate matter (PM2.5) among schoolchildren.. METHODS Toxicological risk assessment was used to evaluate the risk of exposure to O3 and PM2.5 from biomass burning among schoolchildren aged six to 14 years, residents of Rio Branco, Acre, Southern Amazon, Brazil. We used Monte Carlo simulation to estimate the potential intake dose of both pollutants. RESULTS During the slash-and-burn periods, O3 and PM2.5 concentrations reached 119.4 µg/m3 and 51.1 µg/m3, respectively. The schoolchildren incorporated medium potential doses regarding exposure to O3 (2.83 μg/kg.day, 95%CI 2.72–2.94). For exposure to PM2.5, we did not find toxicological risk (0.93 μg/kg.day, 95%CI 0.86–0.99). The toxicological risk for exposure to O3 was greater than 1 for all children (QR = 2.75; 95%CI 2.64–2.86). CONCLUSIONS Schoolchildren were exposed to high doses of O3 during the dry season of the region. This posed a toxicological risk, especially to those who had previous diseases.

Appropriate Exposure Routes and Doses in Studies Designed to Assess Developmental Toxicity: A Case Study of Inorganic Arsenic

1999 ◽  
Vol 18 (5) ◽  
pp. 361-368 ◽  
Author(s):  
Catherine F. Jacobson ◽  
Donald G. Stump ◽  
Mark D. Nemec ◽  
Joseph F. Holson ◽  
John M. DeSesso
Keyword(s):  
Risk Assessment ◽  
Developmental Toxicity ◽  
Inorganic Arsenic ◽  
Careful Analysis ◽  
Complex Process ◽  
Animal Data ◽  
Environmental Agents ◽  
Route Of Exposure ◽  
Exposure Routes

Assessment of risks to human health from chemical agents is a complex process that requires the assembly, careful analysis, and integration of human and animal data collected from studies performed at different times, for disparate purposes, and under varying conditions. The application of risk assessment methods to data without consideration of the relevance of critical experimental parameters such as route of exposure or magnitude of dose can lead to specious determinations of the risk posed by exposure to environmental agents. A case study of the purported risk of developmental toxicity from inorganic arsenic is presented to illustrate (1) the nature of the problem, (2) how extant data from all studies are useful, (3) how appropriately designed modern studies can clarify the situation, and (4) how conflicted data should be evaluated in terms of appropriateness for use in risk assessment.

Use of Toxicokinetics in Risk Assessment Based on In Vitro Data

1993 ◽  
Vol 21 (2) ◽  
pp. 173-180
Author(s):  
Gunnar Johanson
Keyword(s):  
Risk Assessment ◽  
Whole Body ◽  
External Exposure ◽  
Target Dose ◽  
Toxic Response ◽  
Route Of Exposure ◽  
Vitro Data ◽  
In Vitro Data

This presentation addresses some aspects of the methodology, advantages and problems associated with toxicokinetic modelling based on in vitro data. By using toxicokinetic models, particularly physiologically-based ones, it is possible, in principle, to describe whole body toxicokinetics, target doses and toxic effects from in vitro data. Modelling can be divided into three major steps: 1) to relate external exposure (applied dose) of xenobiotic to target dose; 2) to establish the relationship between target dose and effect (in vitro data, e.g. metabolism in microsomes, partitioning in tissue homogenates, and toxicity in cell cultures, are useful in both steps); and 3) to relate external exposure to toxic effect by combining the first two steps. Extrapolations from in vitro to in vivo, between animal and man, and between high and low doses, can easily be carried out by toxicokinetic simulations. In addition, several factors that may affect the toxic response by changing the target dose, such as route of exposure and physical activity, can be studied. New insights concerning the processes involved in toxicity often emerge during the design, refinement and validation of the model. The modelling approach is illustrated by two examples: 1) the carcinogenicity of 1,3-butadiene; and 2) the haematotoxicity of 2-butoxyethanol. Toxicokinetic modelling is an important tool in toxicological risk assessment based on in vitro data. Many factors, some of which can, and should be, studied in vitro, are involved in the expression of toxicity. Successful modelling depends on the identification and quantification of these factors.

Pharmacogenetics

1962 ◽  
Vol 11 (3) ◽  
pp. 338-350 ◽  
Author(s):  
David A. Price-Evans
Keyword(s):  
Animal Species ◽  
The Subject ◽  
Genetically Determined

The term Pharmacogenetics is defined as the study of genetically determined variations in animal species which are revealed by the effects of drugs.I am going to deal with examples of these variations which have been found in Man. I must apologise for a certain amount of repetition of some facts which have already been aired in this conference, but it is my intention to give you a bird's eye view of the subject.

Next generation risk assessment for skin sensitization combining non-animal data and read-across:

2021 ◽  
Vol 350 ◽  
pp. S65
Author(s):  
F. Gautier ◽  
F. Tourneix ◽  
H. Assaf Vandecasteele ◽  
D Bury ◽  
N. Alépée
Keyword(s):  
Risk Assessment ◽  
Skin Sensitization ◽  
Next Generation ◽  
Animal Data

Risk assessment and forest pest management

1991 ◽  
Vol 67 (5) ◽  
pp. 486-492
Author(s):  
Frank N. Dost
Keyword(s):  
Risk Assessment ◽  
High Dose ◽  
Forest Pest ◽  
Potential Harm ◽  
Dose Rates ◽  
Human Risk ◽  
Forest Pest Management ◽  
The Subject ◽  
Management Method ◽  
Normal Background

Prediction of potential harm, or risk assessment, is essential to planning for any vegetation management method, but the concepts and process are often not understood. This discussion is a highly simplistic description of the basic elements of toxicology and estimation of risk in excess of the high normal background. All chemical risk is directly related to the dose acquired by the subject or population. In the case of cancer, added human risk that may be associated with very low doses is expressed as a probability that is estimated by extrapolation from observations at high dose rates. Reasons for such an indirect approach and weaknesses of the present process are described.

Introductory remarks

1981 ◽  
Vol 302 (1468) ◽  
pp. 219-219
Keyword(s):  
State Of The Art ◽  
Biological Processes ◽  
Industrial Workers ◽  
Practical Application ◽  
Electroanalytical Methods ◽  
Secondary Battery ◽  
On Line ◽  
The Subject ◽  
General Aspects ◽  
Cross Fertilization

As its title suggests, the purpose of this Discussion Meeting is to review the present state of the art in industrial electrochemistry. We have sought to bring together academic and industrial workers in this field as well as other interested participants. I hope that as the meeting proceeds, a cross-fertilization of ideas will occur both in the formal sessions and during the breaks. The organizers of this Meeting have given considerable thought to the order in which the different aspects of electrochemistry should be presented. Evidently we had to begin with the fundamentals, after which we decided to deal with the general aspects of electrosynthesis including the developing possibilities of supplying energy to biological processes by electrochem ical means. This led naturally to consideration of electrochemical engineering and electroanalytical methods for on-line control. In one session we shall move to a very practical application of electrochemistry, namely batteries. Beginning with Volta’s simple cell, this application is one of the oldest in electrochemistry. In spite of all the advances in the subject, the possibilities of new primary and secondary battery systems remain as wide as ever. I, for one, shall be most interested to hear the progress reports of our three speakers.

scholarly journals Heat-Not-Burn Tobacco Products: The Devil in Disguise or a Considerable Risk Reduction?

2018 ◽  
Vol 7 (2) ◽  
pp. 8-11 ◽  
Author(s):  
Dirk W Lachenmeier ◽  
Peter Anderson ◽  
Jürgen Rehm
Keyword(s):  
Risk Assessment ◽  
Risk Reduction ◽  
Tobacco Smoke ◽  
Heating System ◽  
Quantitative Risk Assessment ◽  
Toxic Effects ◽  
Tobacco Products ◽  
Toxic Compounds ◽  
Risk Of Exposure ◽  
The Devil

Background: Heat-not-burn (HNB) tobacco products are not burnt but instead are inserted into a tobacco-heating system, which heats the tobacco at temperatures below that required to initiate combustion. This mechanism potentially results in significantly reduced concentrations of heat-generated toxicants in the inhalable aerosol.Method: The margin of exposure (MOE) approach was applied for quantitative risk assessment. The MOE is defined as the ratio between the toxicological threshold and the estimated human intake of the same compound. The higher the MOE, the lower the risk of a compound.Findings: The MOEs were increased by factors of 3 to 415 for the most toxic compounds in tobacco smoke, comparing use of HNB with smoking conventional tobacco products. The combined MOE for all compounds was increased 23-fold, excluding nicotine, or 10-fold including nicotine. Thus, the overall risk for cumulative toxic effects was markedly lower for HNB products.Conclusions: HNB tobacco reduced the risk of exposure to 9 out of the 20 most toxic compounds in tobacco beyond an MOE threshold of 10,000. While our results show that use of HNB products leads to a considerable risk reduction compared to conventional tobacco, the products cannot be considered completely “risk-free” due to risk of exposure to the remaining toxicants with MOE below the threshold.

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