Survey and Risk Assessment of Contaminants in Soil from a Nitrogenous Fertilizer Plant Located in North China

Table 4

Major parameters in the calculation models of hazard quotient.

Parameter	Explanation	Value	Unit
SAF	Reference dose distribution ratio for exposure to soil	0.5	/
Csur	Concentration of contaminants in soil	434	mg/kg
Csub	Concentration of contaminants in underlying soil	434	mg/kg
RfDi	Reference dose for inhalation	7E − 02	/
IOVERnc1	Exposure dose by inhaling gaseous pollutants from the surface soil in outdoor air	9.88E − 06	/
IOVERnc2	Exposure dose by inhaling gaseous pollutants from the underlying soil in outdoor air	1.14E − 06	/
IIVERnc1	Exposure dose by inhaling gaseous pollutants from the underlying soil in indoor air	1.60E − 04	/