[Organic pollutant residues of different origins in Navarra]

An analysis was made of residues of polychlorobyphenyls and trihalomethanes through GC-ECD and of herbicides through HPLC-PAD in samples proceeding from Navarra. Polychlorobyphenyls were detected (0.30 +/- 0.05 and 0.11 +/- 0.05 microg/l) in two of the 106 water samples analysed. Sixty-six food samples were analysed, and polychlorobyphenyls were only found in 8 samples of trout (dissimilar to dioxins: 21-194 microg/kg of fat; similar to dioxins: 41-139 microg/kg of fat). Of 107 fat samples analysed, polychlorobyphenyls dissimilar to dioxins were detected in two (27 +/- 5 and 30 +/- 5 microg/kg). Out of a total of 94 feed samples analysed, polychlorobyphenyls were detected in all the samples (12) of feed for aquaculture and their raw materials; the concentration of polychlorobyphenyls dissimilar to dioxins varied by an interval of 8-247 microg/kg of fat; polychlorobyphenyls similar to dioxins, between 18 and 107 microg/kg of fat. Contamination by polychlorobyphenyls of the fish from aquaculture could be due to the feed used in these exploitations. The average of trihalomethanes in the waters of the southern zone of Navarra (44 +/- 4 microg/l) was higher than those of the middle zone (16 +/- 1 microg/l) and the mountain zone (12 +/- 1 microg/l). The concentration of 99% of the samples fulfilled the norms on halomethanes. A relation was observed between muddiness and the concentration of trihalomethanes. Herbicide (cianazine) was only detected in one of the 135 samples of water analysed, with a concentration of (0.4 +/- 0.2 microg/l) which exceeded the established limit. The use of confirmation techniques (GC-MS, HPLC-MS/MS) would make it possible to validate these results and to expand the number of compounds analysed.