2 Background, Tasks, Modeling Methods …
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Solid theoretical grounds such as quantum mechanics (QM) and density functional
theory (DFT) [29] also make it reliable to predict behavior or properties of arbitrary
chemical molecules created as in silico objects.
Computational toxicology as an interdisciplinary field has profoundly changed
the way people view and interpret the basic concepts of toxicology, and meanwhile
it is continuously borrowing ideas from exterior fields, which greatly promotes the
innovative development of toxicology.
2.3 Modeling Methods for Computational Toxicology
In practice, computational toxicology creates in silico objects that could properly
characterize their real-world counterparts at diverse spatial levels. First of all, each
chemical substance (maybe a compound that is queried by regulators or toxicologists)
would be digitized as an in silico object. This queried chemical object may interact
with or be changed by different in silico situational objects for various research
purposes. Useful information could be generated by running simulations with these
in silico objects, which results in models with controllable parameters that bear
sound or at least reasonable physical meanings. Or otherwise, merely the attributes
of a series queried chemicals could be studied for an underlying pattern that has
some statistical significance, which would typically result in fast predictive but less
mechanistic QSAR models.
2.3.1 Environmental Multimedia Fate Models
The concentrations of chemicals in environmental compartments are the basis for
exposure assessment of chemicals [24]. Regulatory laws or policies about chemicals
require a standardized documentation of the information on the release of chemicals. For example, OECD declares that the emission scenario documents (ESDs,
http://www.oecd.org/env/exposure/esd) which describe source, production, and use
of chemicals should be compiled. ESDs can be used to determine emissions of
chemicals into the environmental compartments, e.g., air, water, and soil etc., which
provide interfaces between human activity and the environmental system.
If the situational objects make a macroscale environmental system and the influence of the queried chemical object on the situational objects is assumed to be
negligible, then the simulated model shall resemble a fugacity model proposed by
Mackay [30]. The fugacity model in brief can describe behavior/fates of a queried
chemical in an idealized environmental system. Typically, a fugacity model consists
of:
(1) several mathematical equations describing the mass balance of the chemical
among several predefined environmental compartments;
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Solid theoretical grounds such as quantum mechanics (QM) and density functional
theory (DFT) [29] also make it reliable to predict behavior or properties of arbitrary
chemical molecules created as in silico objects.
Computational toxicology as an interdisciplinary field has profoundly changed
the way people view and interpret the basic concepts of toxicology, and meanwhile
it is continuously borrowing ideas from exterior fields, which greatly promotes the
innovative development of toxicology.
2.3 Modeling Methods for Computational Toxicology
In practice, computational toxicology creates in silico objects that could properly
characterize their real-world counterparts at diverse spatial levels. First of all, each
chemical substance (maybe a compound that is queried by regulators or toxicologists)
would be digitized as an in silico object. This queried chemical object may interact
with or be changed by different in silico situational objects for various research
purposes. Useful information could be generated by running simulations with these
in silico objects, which results in models with controllable parameters that bear
sound or at least reasonable physical meanings. Or otherwise, merely the attributes
of a series queried chemicals could be studied for an underlying pattern that has
some statistical significance, which would typically result in fast predictive but less
mechanistic QSAR models.
2.3.1 Environmental Multimedia Fate Models
The concentrations of chemicals in environmental compartments are the basis for
exposure assessment of chemicals [24]. Regulatory laws or policies about chemicals
require a standardized documentation of the information on the release of chemicals. For example, OECD declares that the emission scenario documents (ESDs,
http://www.oecd.org/env/exposure/esd) which describe source, production, and use
of chemicals should be compiled. ESDs can be used to determine emissions of
chemicals into the environmental compartments, e.g., air, water, and soil etc., which
provide interfaces between human activity and the environmental system.
If the situational objects make a macroscale environmental system and the influence of the queried chemical object on the situational objects is assumed to be
negligible, then the simulated model shall resemble a fugacity model proposed by
Mackay [30]. The fugacity model in brief can describe behavior/fates of a queried
chemical in an idealized environmental system. Typically, a fugacity model consists
of:
(1) several mathematical equations describing the mass balance of the chemical
among several predefined environmental compartments;