Estimated inputs of organochlorines from the River Ebro into the northwestern Mediterranean

Abstract

Measurements of organochlorines in the particulate and dissolved phases of water of the River Ebro in northeastern Spain, sampled at the mouth at four periods over 1982–1983, are combined with data on daily flows to produce estimates of the inputs of these compounds into the northwestern Mediterranean from this source. Hexachlorobenzene (HCB) was the most abundant of the compounds detected, with an estimated yearly input of 30 kg, followed by PCBs, with a yearly input on the order of 12 kg. The HCB and PCBs are attributed principally to a manufacturing facility on the river. Other estimated yearly inputs are 8 kg of total DDTs, 1 kg each of dieldrin, endrin, and endosulfan, and 2 kg of the total of the several chlordane compounds. Relatively high levels of p,p′-DDT among the DDT compounds indicated recent use or mobilization of DDT. These estimates of river inputs of these contaminants are substantially lower than those used or derived in several recent reviews of contamination problems in the Mediterranean; they support the conclusions of other studies that the principal dispersal pathway of the organochlorines is the atmosphere.