persistent organochlorine residues in livers of six species of ciconiiformes (aves) from spain. | liver samples of 42 birds belonging to 6 species of ciconiiformes (grey heron (n = 17), little egret (n = 12), cattle egret (n = 1), glossy ibis (n = 1), little bittern (n = 1), and white stork (n = 10)), collected from two different zones of spain (ebro delta and madrid) in 1992-1997, were analyzed for organochlorine pesticides and pcbs. sigmapcbs (sum of concentrations of individual congeners), p,p'-dde, hcb, gamma-hch, and heptachlor epoxide were the most prevalent residues detected in all sa ... | 2006 | 16785174 |