Polychlorinated biphenyl congeners, hexachlorobenzene and DDTs in human milk in central Italy.

The concentration of organochlorine pesticides (hexachlorobenzene, p,p'-DDT and p,p'-DDE) and polychlorinated biphenyl (PCB) congeners in human milk from 56 donors in the hospitals of two Italian towns (Certaldo and Grosseto) are reported. The highest levels found were those of p,p'-DDE, which reached a mean of 2276 ng g-1 at Certaldo and 2270 ng g-1 at Grosseto, p,p'-DDT levels were about an order of magnitude less, with means of 350 and 298 ng g-1, respectively. The DDE/DDT ratio was approximately 8, which is much higher than that found in previous studies. Mean total PCBs were 451 and 295 ng g-1, respectively. About 70% of the PCB residues in the sample analysed consisted of only three congeners: 2,2',4,4',5,5' (IUPAC No. 153), 2,2',3,4,4',5' (138) and 2,2',3,4,4',5,5' (180).