181 
LOD 
LOQ 
Sample amount 
Sediment 
Chlorpyrifos-ethyl 
3 ng/kg 
7 ng/kg 
40 g 
Chlorpyrifos-methyl 
8 ng/kg 
25 ng/kg 
40 g 
Biota 
Chlorpyrifos-ethyl 
0.2 pg/kg 
0.6 pg/kg 
3 g 
Chlorpyrifos-methyl 
1.2 pg/kg 
3.6 pg/kg 
3 g 
6.4.1.1 Water 
Chlorpyrifos was determined in sea water samples of the North Sea and Baltic Sea 
which had been collected during 7 cruises in 2003 to 2005 (Table 85 and Table 86, 
Appendix 6.6.8) 
Chlorpyrifos-methyl was below the LOD in nearly all samples. 
Chlorpyrifos-ethyl was found in most samples at concentrations of < 10 to 110 pg/L 
with a median of 26 pg/L. More than 95 % of the values were above the LOD. The 
geographical distribution of concentrations is shown in Figure 35 and Figure 36. 
In the German Bight, clear and steady gradients were not found in all surveys. For 
example, a gradient extending from the coasts to the open sea was observed in May 
2003, whereas the distribution in May and July 2004 was found to be quite uniform. 
Although slightly higher concentrations occurred in the river Elbe at Stade (85 to 180 
pg/L), indicating an input of chlorpyrifos-ethyl to the German Bight, this had no major 
effect on the distribution pattern in the marine waters. Other sources will have to be 
considered as an explanation for the “background level” of 10 to 30 pg/L in the southern 
North Sea and the higher levels found sporadically at the western border of the German 
Bight. The cause may be either atmospheric deposition or inputs from the river 
Rhine/Schelde or the UK.