Calculation of toxic pressure from the contamination levels

13 Calculation of toxic pressure from the contamination levels 

Species sensitivity distributions (SSD) on the basis of NOEC values in the literature were used to calculate the toxic pressure (TP an effect value) from the presence of contaminants in the soil or in the pore water (Rutgers et al., 2001 Posthuma et al., 2002). The effect of the contaminants was corrected for the contaminant levels in the local reference samples (field A)  

Tilburg sewage fields Sample A Sample B Sample C Local IVa (field A) 

Pore water content (j.ig/l) Arsenic 40 167 384 SRCeco (surface water) 890 

Furthermore, the toxic pressure (TPmixture) of all contaminants together was estimated from a simple formula  

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