1,2,4-trichlorobenzene also exceeds the acceptable level (1). None of these pollutants exceeds the standards for off-site receptors. Therefore, it is necessary to calculate the health risk control values of these five pollutants for in situ receptors.
(e) Health risk control values
Since risk characterization finds the cancer risk and hazard quotient of groundwater
pollutants in the given landfill beyond the acceptable levels, the control values
(target levels) are calculated using the HERA model in accordance with the
Technical Guidelines for Risk Assessment of Contaminated Sites (HJ25.3–2014), as
shown in Table 5.13.
As
shown
in
Table 5.13,
the
control
values
of
1,3-dichlorobenzene,1,2,4-trichlorobenzene, chloroform, bromodichloromethane,
dibromochloromethane, calculated based on cancer risk and hazard quotient, are
0.109 mg/L, 0.105 mg/L, 0.0116 mg/L, 0.014 mg/L, and 0.064 mg/L respectively.
Case 2 Groundwater pollution investigation, source intensity evaluation and risk
assessment of a given landfill in Jiangxi Province
(1) Overview of the study area
(a) Geographical conditions
The study area is located in the north frontier of Jiangxi Province, near the Yangtze
River. It neighbors Dongzhi County of Anhui Province in the east, Poyang County
and Duchang Country in the south, and Hukou County in the west, and faces
Susong County and Wangjiang County across the Yangtze River in the north. It is
59 km away from the downtown of Jiujiang City and 194 km from the provincial
capital Nanchang.
• Topography
The overall terrain in the study area is high in the southeast and low in the
northwest. From southeast to northwest, there are low mountains, hills, alluvial
terraces, and rivers and beaches. Due to the compression of rock layers, hills are
formed in the terraces of the south bank of the Yangtze River and (sea-shaped) low
mountains in the northeastern part of the study area.
Table 5.12 Total cancer risk and hazard quotient of pollutants in the given landfill in Hubei
Province
Pollutants
In situ
Off-site
CR
T−on
HI
on
CR
T−off
HI
off
1,3-dichlorobenzene
–
1.78E+00
–
1.19E−14
1,2,4-trichlorobenzene
–
1.84E+00
–
2.31E−49
Chloroform
2.19E−05
1.40E−01
7.89E−08
6.64E−04
Monobromodichloromethane
1.82E−05
–
–
–
Dibromochloromethane
3.98E−06
–
8.04E−16
–
114
5 Application Cases
(e) Health risk control values
Since risk characterization finds the cancer risk and hazard quotient of groundwater
pollutants in the given landfill beyond the acceptable levels, the control values
(target levels) are calculated using the HERA model in accordance with the
Technical Guidelines for Risk Assessment of Contaminated Sites (HJ25.3–2014), as
shown in Table 5.13.
As
shown
in
Table 5.13,
the
control
values
of
1,3-dichlorobenzene,1,2,4-trichlorobenzene, chloroform, bromodichloromethane,
dibromochloromethane, calculated based on cancer risk and hazard quotient, are
0.109 mg/L, 0.105 mg/L, 0.0116 mg/L, 0.014 mg/L, and 0.064 mg/L respectively.
Case 2 Groundwater pollution investigation, source intensity evaluation and risk
assessment of a given landfill in Jiangxi Province
(1) Overview of the study area
(a) Geographical conditions
The study area is located in the north frontier of Jiangxi Province, near the Yangtze
River. It neighbors Dongzhi County of Anhui Province in the east, Poyang County
and Duchang Country in the south, and Hukou County in the west, and faces
Susong County and Wangjiang County across the Yangtze River in the north. It is
59 km away from the downtown of Jiujiang City and 194 km from the provincial
capital Nanchang.
• Topography
The overall terrain in the study area is high in the southeast and low in the
northwest. From southeast to northwest, there are low mountains, hills, alluvial
terraces, and rivers and beaches. Due to the compression of rock layers, hills are
formed in the terraces of the south bank of the Yangtze River and (sea-shaped) low
mountains in the northeastern part of the study area.
Table 5.12 Total cancer risk and hazard quotient of pollutants in the given landfill in Hubei
Province
Pollutants
In situ
Off-site
CR
T−on
HI
on
CR
T−off
HI
off
1,3-dichlorobenzene
–
1.78E+00
–
1.19E−14
1,2,4-trichlorobenzene
–
1.84E+00
–
2.31E−49
Chloroform
2.19E−05
1.40E−01
7.89E−08
6.64E−04
Monobromodichloromethane
1.82E−05
–
–
–
Dibromochloromethane
3.98E−06
–
8.04E−16
–
114
5 Application Cases