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2.2.12 Trifluralin in the marine environment of the North and Baltic Seas 
Since trifluralin had a very low LOQ, it was measurable in most water, sediment and 
fish liver samples from the North Sea and Baltic Sea. Concentrations are very low in 
summer, with a median of 15 pg/L for water samples, 10 ng/kg dw for sediments and 
0.42 pg/kg ww for fish liver. In winter, concentrations in water are about 10 times 
higher. This can be explained by the preferred use of this herbicide as a pre-seed agent 
in winter. The detected trifluralin concentrations in sea water are considerably lower 
than the proposed WFD EQS value of 30 ng/L. 
The concentrations found demonstrate that trifluralin is stable enough in the marine 
environment of the North Sea and Baltic Sea. Concentrations are highest during and 
after the main application season in winter. The tenfold lower concentrations in summer 
demonstrate that trifluralin degrades moderately fast in the (marine) environment. The 
distribution patterns are best explained by a general diffuse burden (e.g. by atmospheric 
deposition) with only minor local sources. 
Trifluralin concentrations in the river Elbe are relatively low and, consequently its 
influence on the German Bight. Summer concentrations of trifluralin in sea water are 
above those of the classical lipophilic pollutants such as HCB, DDT, PCBs or PAHs but 
below those for HCHs. In winter, levels exceed HCH concentrations. Therefore, it will 
be worthwhile continuing to study the behaviour of trifluralin in marine waters. 
Compared to classical pollutants, trifluralin concentrations in sediment are 10 to 100 
times lower. For example, HCH isomer concentrations ranged from 10 to 200 ng/kg at 
the most polluted station in the German Bight (KS 11). The more lipophilic DDD and 
CB153 were in the range of 1000 to 5000 ng/kg. PAHs such as benzo(a)pyrene had 
sediment levels between 40-240 pg/kg. 
The enrichment factor of trifluralin based on the median concentrations in water and 
fish liver is 28’000 (ww) and 113’000 (lw), respectively. The trifluralin levels in biota 
are comparable to those of HCH and HCB, but lower than the concentrations of DDT- 
metabolites and PCB. Typical HCH concentrations in the German Bight varied between