Occurrence Of PCBs Research Articles

Occurrence of PCBs, PCDD/Fs, PBDEs and DDTs in Spanish breast milk: Enantiomeric fraction of chiral PCBs

Concentrations and congener specific profile of DDTs, PCBs and PCDD/Fs have been determined in a number of Spanish breast milk samples. The concentrations found indicate a decreasing tendency compared to previous data from the 1990s. Mean concentrations of 238 ng/g fat weight, 111 ng/g fat weight and 82.1 pg/g fat weight were found for DDTs, PCBs and 2,3,7,8-PCDD/Fs, respectively. When the WHO-TEQs were calculated, PCDD/Fs was the family contributing with the highest percentage to the total (62–84%), followed by the non- ortho PCBs (10–25%) and the mono- ortho PCBs (5–24%). The congener specific accumulation patterns found were comparable to those reported in other studies in industrialised countries. In addition, the levels of 9 PBDEs congeners have been also determined in the breast milk samples. The concentrations ranged from 0.04 to 1.38 ng/g fat weight. The enantiomeric enrichment of a number of chiral PCBs in the breast milk samples, including congeners 84, 91, 95, 132, 135, 149, 171, 174, 176 and 183, has also been studied, for some of them for the first time in this matrix.

Occurrence of Polychlorinated Biphenyls in Fish and Sediment of the Arkansas River Basin, Kansas

sediment samples at 9 of 20 sites and ranged in concentration from 14 to 120 [ig/kg. Sediment samples containing PCBs were primarily from areas with urban land uses. PCBs occur in fish tissues at 12 of 15 sites and ranged in concentration from 7 to 47 [pg/kg. The rate of PCB occurrence in fish was similar for areas with agricultural and urban usage. PCBs were in either sediment or fish in all but three sites. Little correlation was noted, however, between occurrence of PCBs in fish and sediment from the same sampling site. Presence of PCBs can threaten environmental and human health; however, in this study, no samples exceeded levels that are likely to pose an environmental or human health risk.

Residues of organochlorine compounds in starlings (Sturnus vulgaris), 1979

Starlings were collected for the National Pesticides Monitoring Program from 112 sites throughout the contiguous United States and analyzed for organochlorine compounds. Starling samples from 14 sites had greater than 1.0 ppm DDE residues with the highest DDE level being 15.8 ppm in a sample taken near Roswell, New Mexico. The occurrence of PCBs and chlordane isomers increased since the 1976 collection, but DDT, DDE, and dieldrin occurrence decreased. DDE and dieldrin levels decreased since the 1976 collection, but the level of PCBs has increased.