The transportation pathways of triazines were investigated from their origi
ns onwards, in the Marne and the Seine rivers (France). According to the 19
91 survey, the highest total triazine concentration levels (956 ng L-1) wer
e found in the river Marne: 580 ng L-1 for atrazine and 200 ng L-1 for sima
zine, in relation with agricultural practices. The total triazine levels re
ached 829 ng L-1 in the river Seine. The other triazines remained low, from
5 to 75 ng L(-)1. The triazine fluxes were 226 and 404 kg for a 118 d peri
od in the Marne and the Seine rivers, respectively. Out of the treatment pe
riod, triazine peaks were related to river flows with a 48 hr delay between
the peak and the top of the flood. After herbicide treatment, peak concent
rations were closely related with the precipitations. Concerning the river
Marne tributaries, highest atrazine concentrations were found in June, in t
hose which drained the vineyard area. In January, the concentrations were h
igher in periurban areas underlining their contribution to the herbicide in
puts in the rivers. On the whole, the ratio of triazines transported in the
two rivers represented 0.2% of the total amount applicated annually on the
ir catchment basins.