Toxicity data, gathering

None of the lanthanide toxicity data gathered to date indicates that the lanthanides cause long-term health effects such as reproductive or carcinogenic toxicity. 

In general, most submissions made to EPA under TSCA 8(e) contain toxicity data gathered during testing of commercial or research and development chemicals. However, certain types of information on exposure and environmental effects and release must also be reported. 

BioPrint also includes a small animal toxicity data set. Blood chemistry and organ toxicity data have been gathered for more than 200 compounds. 

Many laboratory animal models have been used to describe the toxicity and pharmacology of chloroform. By far, the most commonly used laboratory animal species are the rat and mouse models. Generally, the pharmacokinetic and toxicokinetic data gathered from rats and mice compare favorably with the limited information available from human studies. PBPK models have been developed using pharmacokinetic and toxicokinetic data for use in risk assessment work for the human. The models are discussed in depth in Section 2.3.5. As mentioned previously, male mice have a sex-related tendency to develop severe renal disease when exposed to chloroform, particularly by the inhalation and oral exposure routes. This effect appears to be species-related as well, since experiments in rabbits and guinea pigs found no sex-related differences in renal toxicity. 

Studies aimed at gathering feasibility and toxicity data on new treatments are usually referred to as phase I trials. Phase II trials are relatively small studies (typically with sample size less than or about 100 subjects) with the purpose of detecting preliminary evidence of efficacy and safety. Phase III trials are larger studies with enough statistical power to test in a conclusive way specific hypotheses about treatment effects. The term clinical trials is often broadly used to designate phase III trials. 

The same types of toxicity data were gathered on DMHP acetate as on DMHP.18... 

Since the advent of OSHA (Occupational Safety and Health Administration), tremendous advances have been made in the degree of sophistication and data gathering ability of toxic substance monitoring instrumentation. Traditionally, exposure standards are often limited by the measurement techniques used to determine exposure. The introduction of new, small computers on a chip, particularly those that have an extensive memory and can be programmed, represents a technology that revolutionizes the measurement of occupational exposures, providing more complete and accurate data. A microprocessor-based dosimeter has been developed with this purpose in mind. 

Adequate extrapolation of results from standard laboratory toxicity tests to other time scales of exposure and response requires observations on the time course of toxic effects. These observations can then be used to construct time-to-event models, such as the DEBtox model mentioned above. These models explicitly address both intensity and duration of exposure to hazardous chemicals, and better use is made of the data gathered from toxicity experiments. Diverse endpoints in time can be addressed, and individual organism characteristics and/or environmental circumstances (e.g., temperature) can be incorporated as covariables. An overview of time-to-event models and approaches and their use in the risk assessment of chemicals is provided by Crane et al. (2002). 

First, although there is substantial evidence that many cancers are primarily associated with so-called lifestyle factors , the natural environment including viruses, and even genetics, we certainly cannot rule out some role for industrial chemicals. Moreover, chemicals can cause many other types of adverse health effects about which we do not have significant explanations of any type. Until we have evidence to rule out a significant role for industrial pollutants in human reproductive disorders, diseases of the nervous system, and so on, it would seem imprudent to cease or reduce gathering toxicity data on them and establishing limits on human exposures. 

Although the goals of the statute are quite commendable, EPA has often been criticized for its inability to gather existing toxicity data or to mandate testing of new or existing chemicals. ... 

Chapter 10 closes Part 2 with a discussion of the most reliable and useful environmental epidemiological data gathered for Pb exposure studies in subsets of human populations. Chapter 10 is confined to Pb exposure epidemiology and differs from the various epidemiological studies addressing dose—adverse response relationships appearing in Part 3 as part of the chapters dealing with human lead toxicity. 

Experimental studies of lead s effects on blood-forming and related systems comprise a large hterature, much of it now of some vintage. Such studies clarified the nature and extent of the quantitative scope of Pb s hematotoxi-city. This extended to the impacts of Pb exposures on heme biosynthesis across organs and tissues and the interactions of heme effects with toxic effects in other systems. Illustrative examples of such studies are presented in Table 16.7, summarizing data gathered in avians, rodents, rabbits, and nonhuman primates. 

Shortly after the first list of 80 chemicals targeted for voluntary PBT data gathering was complete, the EPA issued the Waste Minimization Prioritization Tool (WMPT). This was originally a software tool given away in unfinished editions by the EPA for public interest groups to assess various substances in commercial waste streams. The WMPT was designed to assess the persistence, bioaccumulation and toxicity characteristics of chemicals. The scoring system used a maximum of nine points, with three points for persistence, three points for bioaccumulation and three points for toxicity. 

In 2004, Stolte S. et flZ.[155] build a different toxicity model using cytotoxicity data gather from studies including several anions and l-alkyl-3-methylimidazolium cations (with ethyl, butyl and hexyl chains) and perfomed in the IPC-81 rat leukemia cell line. Firstly, intrinsic toxicity of the anions and cations were assessed assuming that sodium chloride and lithium chloride and, the chloride as anion, respectively, had no imp>act on toxicity behaviour. These studies revealed that only 10 anions from a total of 27 demonstrated considerable toxicity... 

Hazard identification involves gathering and evaluating data on the types of health injury or disease that may be produced by a chemical and on the conditions of exposure under which injury or disease is produced. It may also involve characterization of the behavior of a chemical within the body and the interactions it undergoes with organs, cells, or even parts of cells. Hazard identification is not risk assessment. It is a scientific determination of whether observed toxic effects in one setting will occur in other settings. 

Analysts should discuss sample-collection methods with those responsible. Frequently, the methods result in biased data due to venting, failure to blow down the sample lines, and contamination. These are limitations that must either be corrected or accepted and understood. Sampling must be conducted within the safety procedures established for the unit. Since samples may be hot, toxic, or reactive in the presence of oxygen, the sample gatherers must be aware of and implement the safety procedures of the unit. 

At the laboratory stage, data on substances involved and their mixtures must be gathered material properties, physicochemical data, ecological and toxicological data, costs of raw materials and intermediates, an estimate of product price, energy and equipment costs, etc. These data are needed in simulation programs and to determine toxicity, safety, and impact on the environment. The data on toxicity, degradability, and safety are required by the authorities to execute an approval procedure for the plant. 

Under the Toxics Substances Control Act, the Environmental Protection Agency (EPA) is mandated to gather data on the exposure of the general population to toxic substances. Toward this end, the Office of Toxic Substances within the EPA has undertaken several long term monitoring programs. These programs involve the collection of human tissue specimens from a statistically representative... 

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