Toxicological considerations risks

The necessary containment or transport capability of a local ventilation sy stem depends on the type of contaminant present and its health risks. There could be different demands for gases and particles, for contaminants that have immediate health risks and those that have long-term effects, for contaminants that affect the breathing system and those that affect the skin and eyes, for infectious contaminants, fot contaminants that follow the air streamlines closely and those that fall out on floor and work surfaces, etc. (See Chapter 5 for physiological and toxicological considerations.)... 

The ADI Is the dally exposure level of a pesticide residue which, during the entire lifetime of man, appears to be without appreciable risk based on all facts known at the time. The ADI Is based on toxicological considerations only and Is Independent of level of exposure. 

O Halloran K. 2006. Toxicological considerations of contaminants in the terrestrial environment for ecological risk assessment. Human Ecol Risk Assess 12 74-83. 

GENETIC TOXICOLOGY AND RISK ASSESSMENT (GENERAL CONSIDERATIONS) 589... 

Oettel M (2003) Testosterone metabolism, dose-response relationships and receptor polymorphisms Selected pharmacological/toxicological considerations on benefits versus risks of testosterone therapy in men. Aging Male 6 230-256. 

Brooke, 1. M. (1998). A UK scheme to help small firms control health risks from chemicals toxicological considerations, Annals of Occupational Hygiene, Vol. 42, No 6 pp 377-390. 

Physiologically based toxicokinetic models are nowadays used increasingly for toxicological risk assessment. These models are based on human physiology, and thus take into consideration the actual toxicokinetic processes more accurately than the one- or two-compartment models. In these models, all of the relevant information regarding absorption, distribution, biotransformarion, and elimination of a compound is utilized. The principles of physiologically based pharmaco/ toxicokinetic models are depicted in Fig. 5.41a and h. The... 

In order to understand the use and intent of the various immunotoxicology regulatory guidelines and guidance documents, the difference between two concepts familiar to toxicologists should be emphasized. Hazard, identification refers to a method which is essentially qualitative that is, it is designed to detect the ability of a test article to produce a certain (in the context of toxicology) adverse effect, without reference to exposure issues. Risk assessment, on the other hand, takes into consideration method, dose, and duration of exposure, condition(s) of the exposed population, and concurrent... 

Basketter, D.A. et al., Pathology considerations for, and subsequent risk assessment of, chemicals identified as immunosuppressive in routine toxicology, Food Chem, Toxicol., 33, 239,1995. 

Intakes that exceed the ADI will not necessarily result in any adverse effect because the uncertainty factors are designed to be conservative. In practice it is probable that most people could exceed the ADI by a considerable margin before suffering any harm. Nevertheless, the probability that an individual will suffer harm (risk) increases once the ADI is exceeded and so this must be balanced against the costs of control. Conversely, the level of risk below the ADI is never quite zero because there is always a residual risk that relates to the lack of absolute certainty in the methods used for toxicological testing. In some cases no adverse end-point can be identified, such as for many naturally-occurring compounds that are widespread in foods. In such cases an ADI Not Specified (ADI NS) is allocated. 

Risk management combines the risk assessment with economic, political, public opinion, and other considerations to determine a course of action. These judgments seldom satisfy everyone. The principles of toxicology form the foundation for the risk assessment and ultimately for the risk management decisions. Individual and community involvement in the decision-making process is a critical part of developing sound policies to minimize risks to people and the environment. 

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