4.1.1 Process of Health Risk Assessment
4.1.1.1 Hazard Identification
Hazard identification is a process of qualitatively determining whether exposure to a
chemical substance causes or increases the incidence of specific diseases (e.g.
cancers and birth defects), which is essential to human health risk assessment. In the
case of chemical substances, the process examines whether such substances are
harmful to human health by collecting and evaluating the toxicological and epidemiological data. Internationally, there are two methods for classifying chemical
substances: the International Agency for Research on Cancer (IARC) system and
the Integrated Risk Information System (IRIS) prepared by the US EPA. In China,
the Technical Guidelines for Environmental Impact Assessment: Human Health
(Draft for Comment), jointly released by the Chinese Research Academy of
Environmental Sciences (CRAES) and the School of Public Health of Peking
University (PKU-SPH) in 2008, incorporated the IRIS database as the main reference. The Technical Guidelines for Risk Assessment of Contaminated Sites (Draft
for Approval), issued by the Ministry of Environmental Protection of China (MEP),
published the toxicity parameters for exposure to some pollutants through different
pathways. Apart from these, China has not yet established a relatively complete
database of pollutant toxicity.
Based on preliminary and detailed investigations, sampling and analysis, hazard
identification encompasses the following tasks: collecting EIA data and project
acceptance data of enterprises through communication with technical personnel;
based on planned land use, identifying the main pollutants in contaminated sites and
their potential scope; determining site use, focus pollutants and their spatial distribution; identifying the types of sensitive receptors and the parameters for site
characteristics; establishing the system for data quality management and control
target; and further refining the conceptual model of contaminated sites to guide risk
assessment.
The sources of data for hazard identification include environmental monitoring
data, epidemiological studies and biotoxicological studies. As to specific content,
hazard identification involves identifying the types of pollutants that may threaten
human health; measuring the concentrations of pollutants in the environment;
assessing the toxicity of pollutants under different conditions; and determining the
structure of pollutants.
The hazard identification of groundwater contamination sites examines carcinogenic and non-carcinogenic virulence factors of focus pollutants based on the
following sequence of materials:
• Technical Specifications of Risk Assessment of Contaminated Sites issued by
MEP (HJ 25.3–2014);
• Guidelines for Health Risk Assessment of Groundwater Pollution (Trial)
(October 2014);
• IRIS;
4.1 Health Risk Assessment of Typical Groundwater Contamination Sites
69
4.1.1.1 Hazard Identification
Hazard identification is a process of qualitatively determining whether exposure to a
chemical substance causes or increases the incidence of specific diseases (e.g.
cancers and birth defects), which is essential to human health risk assessment. In the
case of chemical substances, the process examines whether such substances are
harmful to human health by collecting and evaluating the toxicological and epidemiological data. Internationally, there are two methods for classifying chemical
substances: the International Agency for Research on Cancer (IARC) system and
the Integrated Risk Information System (IRIS) prepared by the US EPA. In China,
the Technical Guidelines for Environmental Impact Assessment: Human Health
(Draft for Comment), jointly released by the Chinese Research Academy of
Environmental Sciences (CRAES) and the School of Public Health of Peking
University (PKU-SPH) in 2008, incorporated the IRIS database as the main reference. The Technical Guidelines for Risk Assessment of Contaminated Sites (Draft
for Approval), issued by the Ministry of Environmental Protection of China (MEP),
published the toxicity parameters for exposure to some pollutants through different
pathways. Apart from these, China has not yet established a relatively complete
database of pollutant toxicity.
Based on preliminary and detailed investigations, sampling and analysis, hazard
identification encompasses the following tasks: collecting EIA data and project
acceptance data of enterprises through communication with technical personnel;
based on planned land use, identifying the main pollutants in contaminated sites and
their potential scope; determining site use, focus pollutants and their spatial distribution; identifying the types of sensitive receptors and the parameters for site
characteristics; establishing the system for data quality management and control
target; and further refining the conceptual model of contaminated sites to guide risk
assessment.
The sources of data for hazard identification include environmental monitoring
data, epidemiological studies and biotoxicological studies. As to specific content,
hazard identification involves identifying the types of pollutants that may threaten
human health; measuring the concentrations of pollutants in the environment;
assessing the toxicity of pollutants under different conditions; and determining the
structure of pollutants.
The hazard identification of groundwater contamination sites examines carcinogenic and non-carcinogenic virulence factors of focus pollutants based on the
following sequence of materials:
• Technical Specifications of Risk Assessment of Contaminated Sites issued by
MEP (HJ 25.3–2014);
• Guidelines for Health Risk Assessment of Groundwater Pollution (Trial)
(October 2014);
• IRIS;
4.1 Health Risk Assessment of Typical Groundwater Contamination Sites
69