Human exposure overview

Coughlin, J.R. 1998. Sources of human exposure. Overview of water supplies as sources of boron. Biol. Trace Elem. Res. 66 87-100. 

To evaluate human exposure to phthalates and their substitutes, the main approaches investigate either the levels of chemicals in matrices relevant for human exposure (indoor air, dust, food and packages, etc.) or the levels of parent and metabolite compounds in human samples (serum, urine, or breast milk). An overview of phthalate and nonphthalate plasticizers together with their metabolites commonly reported in literature is presented in Table 5. The half-lives for the most of these compounds are already established and therefore, by evaluating the levels of their metabolites in human urine, the levels of their parent compounds may be... 

Abstract Phthalates are chemicals that have been used for over 80 years in large quantities due to their wide range of applications, mainly in the plastic industry. For many years, these compounds were not considered dangerous for humans due to their low toxicity shown in the preliminary studies and their low persistence. However, research conducted in recent years has evidenced their activity as endocrine disrupters, and they are now considered as emerging contaminants and included in the priority list of dangerous substances in the legislation of many countries. This chapter provides an overview on the properties, major uses, emission sources, environmental and human levels, current legislation, behavior and fate of phthalates, and their metabolites, with special emphasis on their toxicity and human exposure. 

In Chapter 1 Bruce N. Ames, the plenary speaker at the symposium, describes the development of the Salmonella/microsome assay, which is better known as the Ames Test. This test was the first proven rehable and rapid in-vitro method for the mutagenic and carcinogenic screening of chemicals. Included is an excellent overview of the potential problem of human exposure to toxic substances as well as a description of how this important method is being used to test chemical substances. 

CDC has been a major player in funding both state and national biomonitoring programs. NHANES and the National Reports on Human Exposure to Environmental Chemicals have provided regulators with a comprehensive overview of exposures in the general population to selected chemicals. 

The exposure assessment characterizes the pathways, magnitude, frequency, and duration of human exposures from various sources. Chapter 5 provides an overview of these components and addresses the principles of exposure assessment in children. General principles of exposure assessment have been reviewed in a number of publications (USEPA, 1992a, 2005a IPCS, 1999a, 2000 Needham et al., 2005). This chapter will focus on the considerations that are important when applying the exposure data to a children s health risk assessment (see Box 2). 

McKone, T.E. (1991). Human exposure to chemicals from multiple media and through multiple pathways Research overview and comments. Risk Anal, 11, 5-10. 

A brief statement or overview of the toxicology, including the extent of the data and information retrieved and reviewed, highlights of the most important research and strengths and weaknesses of the database. Discuss data on human exposures and data on laboratory animals. 

Overview of Health Effects. Studies in humans and animals indicate that inhalation of asbestos fibers may lead to fibrotic lung disease (asbestosis), pleural plaques and thickening, and cancer of the lung, the pleura, and the peritoneum. It may also increase the risk of cancer at other sites, but the evidence is not strong. Significant effects on other tissues have not been detected. A number of researchers have found that the occurrence of asbestosis and lung cancer correlates with cumulative exposure (that is, the product of concentration [PCM fibers/mL] multiplied by years of exposure). Therefore, human exposures are expressed below as PCM f-yr/mL. Animal data are provided in terms of exposure level (PCM f/mL) and duration, and the cumulative exposure can be found simply by calculating the product. However, due to differences in clearance rates and lifespan as well as other differences, cumulative doses in animals are not expected to be directly comparable to cumulative doses in humans. Studies that provide reliable dose-... 

Belaud FA, Poirier MC. 1991. Biomarkers of human exposure to carcinogens An overview. Biomed Environ Sci 4(l-2) 69-72. 

Overview of the Use, Safety Issues, and Human Exposure to Food Contact Materials... 

Overview. Humans living in areas surrounding hazardous waste sites may be exposed to endosulfan primarily via dermal contact with or ingestion of contaminated soils since this compound is found bound to soil particles. Although endosulfan can be found in water as colloidal suspensions adsorbed to particles, ingestion of contaminated finished drinking water is not expected to be a major route of exposure since endosulfan is not very water soluble. Likewise, inhalation exposure to endosulfan via volatilization from contaminated media is not a major route of exposure since endosulfan is not very... 

The impairment of heme synthesis by lead has a far-ranging impact not limited to the hematopoietic system. EPA (1986a) provided an overview of the known and potential consequences of the reduction of heme synthesis as shown in Figure 2-11. Well documented effects are indicated by solid arrows, and effects considered to be plausible further consequences of the impairment of heme synthesis are indicated by dashed arrows. Additional discussion is provided in the following sections on renal and neurological effects. More detailed information on the exposure levels or blood lead levels at which these impacts may be experienced was provided in Section 2.2 and the relevance to human health is discussed in Section 2.5. 

Archer, V.J., Oncology Overview, Selected Abstracts on Risk of Cancer from Exposure to Low Level Ionizing Radiation, PB84-922906, International Cancer Research Data Bank Program, National Cancer Institute, U.S. Department of Health and Human Services, Salt Lake City, Utah, (August 1984) ... 

Numerous cases of arsine poisoning have been reported (Elkins and Fahy 1967 DePalma 1969). However, these reports lack definitive exposure concentration data and usually lack exposure duration data as well. Some of the more recent and complete reports involving nonlethal consequences are described in the following section. These reports do not provide quantitative data suitable for AEGL derivations, but they do provide valuable insight into the nature and progression of arsine poisoning in humans. In most cases, the severity of the effects was usually sufficient to necessitate medical intervention to prevent lethality. Some of the more prominent reports and those with the best descriptive data have been summarized, but the overview is by no means exhaustive. 

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