212 
concentrations up to 100 mg/L. In contrast, Dicofol was found to have a significant 
influence on embryonic development at concentrations of 2-10 mg/L (Table 81). 
Table 81: Influence of dicofol on the embryonic development of Danio rerio\ number of eggs 60, limit of 
significance 10 % (Kammann, BFA, 2004) 
Effect 
EC50 [mg/L] 
Léthal 
11 
Non-lethal 
2.1 
Variances on vertébral column 
7.3 
Formation of oedema 
5.3 
Coagulation 
11 
Endpoints of the investigation were coagulation and lethal variances in the embryo 
(somits, caudal ablation, spontaneous motion, cardioplegia) as well as non-lethal 
variances (vertebral column, oedema, pigments, pigments of eyes, disposition of eyes). 
A literature survey yielded no indication of any other toxicity risk of DCB; it is not 
considered toxic. 
6.4.6.3 Discussion 
Dicofol was not detectable in sea water from the North Sea and Baltic Sea (LOD: 0.3 
ng/L). Degradation experiments in sea water showed a half-life of less than a day. 
Therefore, no further investigations in sediments or biota were carried out. Also LOD 
lowering to the lower pg/L range was not considered to be of priority interest in the 
project. 
Walsh and Hites (1979) showed that the degradation of dicofol in water depends on the 
pH and increases under neutral and basic pH conditions. As sea water has a basic pH 
value between 8 and 8.5, this is supported by the quick degradation observed in sea 
water and the fact that up to now no occurrence of dicofol in marine waters has been 
reported in literature. 
In the river Elbe - generally the most important source of pollutant input to the German 
Bight - no dicofol was detected but its degradation product DCB was present at 3.8