Site-specific risk assessment and management of point and diffuse sources - Environmental Deterioration and Contamination: Problems and their Management - page 356

- SF = slope factor [1/(mg/kg*day)]

- LT = lifetime (year)

tolerable cancer risk (10 − 6 ) - TR =

- ED = exposure duration (year)

- AF = absorption factor

The results of the calculation—without showing the details—are given below.
Risk based screening concentration (RBSC) in the groundwater used for direct water
consumption:

RBSC tox adult = 0.36 mg/L;

=

RBSC tox child 0.16 mg/L;

=

RBSC carc adult 0.003 mg/L;

RBSC carc child = 0.006 mg/L.

Risk-based screening levels in the groundwater used for irrigation: direct exposure
through inhalation, ingestion and dermal contact:

RBSC tox adult = 8.32 mg/L;

RBSC tox child = 2.31 mg/L;

RBSC carc adult = 0.06 mg/L;

RBSC carc child = 0.14 mg/L.

Risk-based screening levels in the groundwater used for irrigation of the vegetables
consumed by the adult and child residents:

RBSC tox adult = 3.31 mg/L;

RBSC tox child = 1.86 mg/L;

RBSC carc adult = 0.025 mg/L;

RBSC carc child = 0.070 mg/L.

Risk-based screening levels in the groundwater used for watering the animals whose
products are consumed by adult and child residents:

=

RBSC tox adult 6833 mg/L;

RBSC tox child 3442 mg/L;

RBSC carc adult =

=

51.4 mg/L;

RBSC carc child = 130 mg/L.

Risk-based screening levels in the groundwater calculated from the acceptable concen-
tration in indoor air:

RBSC tox adult = 0.2 mg/L;

RBSC tox child = 0.05 mg/L.

From the results it is obvious that the use of the chloroform-contaminated ground-
water as drinking water poses the highest risk to humans, the risk-based screening