Environment exposure assessment

Most human or environmental healtli hazards can be evaluated by dissecting tlie analysis into four parts liazard identification, dose-response assessment or hazard assessment, exposure assessment, and risk characterization. For some perceived healtli liazards, tlie risk assessment might stop with tlie first step, liazard identification, if no adverse effect is identified or if an agency elects to take regulatory action witliout furtlier analysis. Regarding liazard identification, a hazard is defined as a toxic agent or a set of conditions that luis the potential to cause adverse effects to hmnan health or tlie environment. Healtli hazard identification involves an evaluation of various forms of information in order to identify the different liaz.ards. Dose-response or toxicity assessment is required in an overall assessment responses/cffects can vary widely since all chemicals and contaminants vary in their capacity to cause adverse effects. This step frequently requires that assumptions be made to relate... 

Exposure assessment is the process of measuring or estimating llic intensity, frequency, and duration of human or animtil exposure to an agent present in llie environment... 

The exceeded value for children via the environment from exposure to dioctyltin (356% of the TDI) relates to the consumption of local produce close to a PVC processing plant and largely derives from default values on release to the environment. Further refinement of this exposure assessment is currently under way. Until this is clarified, dioctyltin remains a compound of concern via this exposure route for children. 

Wallace LA, Pellizzari ED, Hartwell TD, et al. 1986a. Total exposure assessment methodology (TEAM) study Personal exposures, indoor-outdoor relationships, and breath levels of volatile organic compounds in New Jersey. Environ Int 12 369-387. 

Wallace LA, Pellizzari ED, Sheldon L, et al. 1986d. The total exposure assessment methodology (TEAM) study Direct measurement of personal exposures through air and water for 600 residents of several U.S. cities. In Cohen Y, ed. Pollutants in a multimedia environment. New York, NY Plenum Publishing Corp., 289-315. 

The Office of Pollution Prevention and Toxics (OPPT) has developed a series of methods, databases, and predictive models to help in evaluating what happens to chemicals when they are used and released into the environment. These tools are intended to be used by scientists and engineers famihar with exposure assessment principles. 

Richard C. Honeycutt, Ph.D., was born in Newport News, VA, in 1945. He attended Anderson University in Anderson, IN, from 1963 to 1967 and earned an A.B. in Chemistry. He received his Ph.D. in Biochemistry from Purdue University in 1971 and served as a Postdoctoral Fellow from 1971 to 1973 at the Smithsonian Institution s Radiation Biology Laboratory. Dr. Honeycutt worked as a Senior Chemist at Rohm and Haas Company from 1973 to 1976 and as a Senior Metabolism Chemist at Ciba Geigy from 1976 to 1989. Currently, he is President of the Hazard Evaluation and Regulatory Affairs Company, Inc., which he founded in 1990, and is an analytical biochemist and field research specialist/consultant engaged in exposure assessment of pesticides to humans and the environment. 

Gobas FAPC, Pasternak JP, Lien K, Duncan RK (1998) Development and field validation of a multimedia exposure assessment model for waste load allocation in aquatic ecosystems application to 2,3,7,8-tetrachlo-rodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in the Fraser river watershed. Environ Sci Technol 32(16) 2442-2449... 

In this chapter the risk assessment is briefly introduced. Risk assessment is divided into four steps hazard identification, hazard characterization, exposure assessment, and risk characterization. This chapter also highlights five risk and life cycle impact assessment models (EUSES, USEtox, GLOBOX, SADA, and MAFRAM) that allows for assessment of risks to human health and the environment. In addition other 12 models were appointed. Finally, in the last section of this chapter, there is a compilation of useful data sources for risk assessment. The data source selection is essential to obtain high quality data. This source selection is divided into two parts. First, six frequently used databases for physicochemical... 

Due to this, it is necessary to assess the risk to human health and the environment due to the exposure to these chemical additives. In this chapter the impacts that a substance can cause to a certain receptor (humans and the environment) and the harms to the receptor at different exposure levels are identified in hazard identification and hazard characterization steps, respectively. Exposure assessment takes into account the amount, frequency, and duration of the exposure to the substance. Finally, risk characterization evaluates the increased risk caused by such exposure to the exposed population. 

For human health risk assessment, it is necessary to elaborate realistic scenarios. Knowledge of real scenarios where the contaminant is emitted to the environment will help to obtain information about the fate and transport of the contaminant once emitted to the environment and the route of exposure for the human beings living in this scenario of concern. There are different types of exposure, i.e., direct, indirect (as is the case of food contaminated by the air, water, or soil contaminated by the emission), occupational exposure, and consumer goods coming from outside the scenario of concern. Depending on the objective of the study, it will be necessary to consider in the exposure assessment one or more types of exposure. 

Exposure calculation to the emission calculations involving impact of emissions on humans and ecosystem of the emissions means the impact calculation of the dose from the increased concentration. The impact calculation is followed by calculation of impacts (damage in physical units) from this dose, using a dose-response function. The impact of WEEE substances on health and the environment is location specific and is based on conditional, that is to say the way the WEEE is taken care of. Hence, the exposure assessment relates to the population and the ecosystem being exposed to the externalities. 

Fromme H, Tittlemier SA, Volkel W, Wilhelm M, Twardella D (2009) Perfluorinated compounds-exposure assessment for the general population in Western countries. Int J Hyg Environ Health 212(3) 239-270... 

Li Y, Huo X, Liu J, Peng L, Li W, Xu X (2010) Assessment of cadmium exposure for neonates in Guiyu, an electronic waste pollution site of China. Environ Monit Assess 177 343-351... 

Al-Yakoob, S.N., T. Saeed, and H. Al-Hashash. 1994. Polycyclic aromatic hydrocarbons in fish exposure assessment for Kuwaiti consumers after the Gulf oil spill of 1991. Environ. Int. 20 221-227. 

Custer, T.W. and C.A. Mitchell. 1991. Contaminant exposure of willets feeding in agricultural drainages of the lower Rio Grande valley of south Texas. Environ. Monitor. Assess. 16 189-200. 

Dietert, R.R. and Piepenbrink, M.S., Perinatal immunotoxicity why adult exposure assessment fails to predict risk, Environ. Health Perspect., 114, 477, 2006. 

These quantitative values of exposure to heavy metals in the relevant pathway are of importance for environment risk assessment procedures in the forest ecosystems areas. 

Exposure assessment a) For the human population, workers, consumers and indirect exposure via the environment b) For the different environment compartments likely to be exposed to the substances water, sediment, soil, and air ... 

The aim of the exposure assessment is to predict the concentration of the substance that is likely to be found in the environment, i.e., the predicted environmental concentration (PEC). Again it may not be possible to establish a PEC, and a qualitative estimation of exposure has to suffice. 

Exposure Assessment. What is the dose or the level of exposure of humans to the chemical agent This question must be asked in the context of a given policy for controlling the uses and dissemination into the environment of a chemical agent. This control policy might be the present situation, a possible new regulatory policy, or a policy that a chemical manufacturer or distributor could choose to impose on his product. It Is usually appropriate to assess the exposure of specific groups of people, Which may depend on occupation, life style, purchases and uses of certain products, etc. 

Recent regulatory thinking has focused on site-specific criteria derived from assessments of the risks to human health and the environment. Risk assessments are based on concentration of contaminants and exposure pathways. 

Daniels, S.L., Hoerger, F.D., and Moolenar, R.J. Environmental exposure assessment experience under the Toxic Substance Conttol Act, Environ. Toxicol. Chem., 4(1) 107-117, 1985. 

Haddad S, Tardif GC, Tardif R (2006) Development of physiologically based toxicokinetic models for improving the human indoor exposure assessment to water contaminants trichloroethylene and trihalomethanes. J Toxicol Environ Health A 69(23) 2095-2136... 

Golet EM, Xifra I, Siegrist H et al (2003) Environmental exposure assessment of fluoroquinolone antibacterial agents from sewage to soil. Environ Sci Technol 37 3243-3249... 

Shi ZX, Wu YN, Li JG, Zhao YE, Eeng JE (2009) Dietary exposure assessment of Chinese adults and nursing infants to tetrabromobisphenol-A and hexabromocyclododecanes occurrence measurements in foods and human milk. Environ Sci Technol 43 4314 319... 

Silva MJ, Reidy JA, Preau JL Jr, Needham LL, Calafat AM (2006) Oxidative metabolites of diisononyl phthalate as biomarkers for human exposure assessment. Environ Health Perspect 114 1158-1161... 

Table 8.1 Component groups for gasoline based on C- number and main chemical composition. Reprinted with permission from Foster KL, Mackay D, Parkerton TF, Webster E, Milford L (2005) Five-stage environmental exposure assessment strategy for mixture gasoline as a case study. Environ Sci Technol 39 2711-2718. Copyright 2005 American Chemical Society...

For both human health and the environment, the risk assessment process includes (i) an exposure assessment, (ii) an effect assessment (hazard assessment and hazard characterization -addressed in detail in Chapter 4), and (iii) a risk characterization (addressed in detail in Chapter 8). As a part of the effect assessment, classification and labeling of the substance according to the criteria laid down in Directive 67/548/EEC (EEC 1967) is also addressed (Section 2.4.1.8). 

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