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Health Risk Assessment
Published in Mary K. Theodore, Louis Theodore, Introduction to Environmental Management, 2021
Generally, the main pathways of exposure considered in this step are atmospheric transport, surface and groundwater transport, ingestion of toxic materials that have passed through the aquatic and terrestrial food chain, and dermal absorption. Once an exposure assessment determines the quantity of a chemical with which human populations may come in contact, the information can be combined with toxicity data (from the health problem identification and dose–response process) to estimate potential health risks [3]. The primary purpose of an exposure assessment is to determine the concentration levels over time and space in each environmental media where human and other environmental receptors may come into contact with chemicals of concern. There are four components of an exposure assessment: potential sources, significant exposure pathways, populations potentially at risk, and exposure estimates [2].
Toxics of the law
Published in Nertila Kuraj, REACH and the Environmental Regulation of Nanotechnology, 2019
If a dose-response relationship can be established during exposure assessment, then risks can be quantified (PEC/PNEC or NO(A)EL/DNEL ratios). The role of exposure assessment is to provide information about the distribution of expected magnitude of exposure, its source and routes, and the individuals of a population that are exposed.208 However, the likelihood or frequency of exposure is a difficult concept to explain objectively, although an attempt is made to quantify it using empirical statistics.209 This leads to the need to understand the fine distinction between uncertainty and variability in the data generation process, since its consequences on the regulatory plan are all but negligible, especially precaution-wise speaking.
Chemical health risks
Published in Blanca Jiménez, Joan Rose, Urban Water Security: Managing Risks, 2009
Inés Navarro, Francisco J. Zagmutt
In the case of chemical risk related to water, the hazard identification consists of finding the components in the water that are hazardous and are present in sufficiently high concentrations to adversely affect health. Dose–response assessment for chemical contaminants includes data on the detrimental effect of chemicals and toxicological data, mainly obtained through research on test organisms, which are used to determine the acceptable dose for humans (Aertgeerts and Angelakis, 2003). Exposure assessment is the process of estimating or measuring the magnitude, frequency and duration of exposure to a chemical agent, along with the number and characteristics of the population exposed. Ideally, the sources, pathways, routes and uncertainties are described during the assessment (IPCS, 2004). Exposure assessment is based on exposure scenarios, which are defined as a combination of facts, assumptions and inferences that define a discrete situation where potential exposures may occur. Exposure factors summarize data on human behaviour and characteristics that affect exposure to environmental contaminants (US EPA, 1997a). In addition, risk characterization is the phase of a risk assessment that combines the results of the characterizations of exposure and effects to estimate the risks to each endpoint, and estimates the uncertainties associated with the risks.
Occupational exposure to respirable dust from the coal-fired power generation process: sources, concentration, and health risk assessment
Published in Archives of Environmental & Occupational Health, 2020
Ruipeng Tong, Jiefeng Liu, Xiaofei Ma, Yunyun Yang, Guohua Shao, Jianfeng Li, Meng Shi
As an essential part of health risk assessment, exposure assessment is defined as the process of determining the exposure level, exposure route, and occurrence frequency of human being exposed to hazardous substances. There is no doubt that identification of exposure pathways is a prerequisite for exposure assessment. The population is exposed to various respirable dust mainly from inhalation through the nose or mouth, apart from oral intake from ingestion and dermal absorption via skin contact. Especially in industrial environments with a high concentration of ambient dust like coal-fired power plants, dust inhalation is inevitable when employees are processing the coal.19 According to a detailed investigation on routine activities during coal-fired power generation, operators in the production sectors all wear staff uniforms that leave a tiny area of the skin bare. Moreover, behaviors like eating and smoking are absolutely forbidden during working hours, which prevents the oral intake of dust to a large extent. Also, the previous study considered dust inhalation as the only source of risk.32 Hence, in this paper, we analyzed the workers’ exposure to respirable dust just from the inhalation pathway with ignoring other exposure routes.
Association of air quality with respiratory and cardiovascular morbidity rate in Delhi, India
Published in International Journal of Environmental Health Research, 2018
Sanjoy Maji, Santu Ghosh, Sirajuddin Ahmed
Characterization of exposure is a central issue in epidemiological studies in order to understand the health effects of air pollutants. Exposure assessment of air pollutants is useful to provide a general understanding of the intensity and diversity of exposure within a population. Information on human-exposure bridges the link between sources of contaminants in the environment and potential human-health-effects. Proper exposure assessment helps in quantifying the health burden of air pollutants concentration and is thereby an integral part of air pollution management. One of the biggest highlight of the present analysis is that morbidity data and air pollution data were available on two different scales. Health data were available as monthly counts whereas exposure data were available as daily 24 h average pollution levels. Exposure metrics that explain the health outcome variation better was selected as a measure of exposure. However to derive the representative exposure for the whole month to scope comparability across the studies globally, we explored alternative monthly metrics of exposure, as minimum, 25th percentile, median, mean, 75th percentile and maximum of the pollutant concentration over the month. Figures 11–14 represent change in effect estimate of hospital admission rate at different exposure metrics of PM10, NO2, CO, and O3, respectively.
Human health risk assessment of Tire and Road Wear Particles (TRWP) in air
Published in Human and Ecological Risk Assessment: An International Journal, 2020
Marisa L. Kreider, Ken M. Unice, Julie M. Panko
Exposure assessment is the process through which the exposure of biological receptors (humans in the case of health risk assessment) to substances present in the environment is estimated and/or measured. Components of an exposure assessment include estimates of exposures based magnitude and duration of exposure and identification of exposure scenarios based on exposed population and exposure patterns. Collectively, these two components are used to determine scenario-specific exposure estimates that can be used for comparison to screening values to determine the risk for that scenario.