Human milk as a vector and an indicator of exposure to PCBs and PBDEs: temporal trend of samples collected in Rome.

Thirty-seven polychlorobiphenyl (PCB) congeners and seven polybromodiphenylether (PBDE) congeners were measured in human milk samples collected in Rome between 2005 and 2007. The comparison of results with two previous studies performed in Rome in 1984 and in 2000-2001 indicates a 64% decrease of PCB levels, still in progress; profile differences with time were also evident as lighter congeners are less relevant now; data are in good agreement with recent European studies. PBDE contamination profiles were different in individual samples and a similar variability was observed in data from different countries, suggesting different exposure pathways and profiles.

Environmental and biological monitoring of endocrine disrupting chemicals.

Trends toward an increase of adverse health effects on reproductive organs have been reviewed. An urgent need has been recognised to establish validated in vivo and in vitro screening assays to test for hormonal activities of chemicals. Relevant existing OECD guidelines have been reviewed and enhancements of some of these have been identified, mainly to test for estrogenic and androgenic activity of chemicals. The problems connected to monitoring activities are outlined, particularly for ambient and biological monitoring. Indeed, the problem of assessing human exposure to endocrine disrupting chemicals through environmental chemical analysis tends to a very high level of complexity. This has been illustrated through the example of one single subclass of endocrine disrupting compounds (EDCs), the organohalogen compounds. Valid biological markers are also needed to be effectively used in epidemiological studies and risk assessment. A multidisciplinary approach and the collaboration among experts in the field of clinical biochemistry, toxicology, and epidemiology is required.

PAH content and mutagenicity of marine sediments from the Venice lagoon.

Sediments from the Venice lagoon, a polluted coastal environment in northeastern Italy, were assayed for mutagenicity and content of several toxic microcontaminants, which included selected polycyclic aromatic hydrocarbons (PAHs); the latter are specifically dealt with in this paper. Samples were collected at three lagoon sites with reasonably distinct environmental features--urban, industrial, or agricultural--and at two others considered to be under mixed pollution influences; a sixth sample was obtained from an open sea area to act as background control. The organic matter (EOM) associated with the mineral substrata was extracted; after cleanup, analyte determination was carried out by HRGC-LRMS(SIM) using isotopically labeled compounds as internal standards. Cumulative levels of the selected PAHs were found to be in the range of 0.065 to 0.46 micrograms/g of dry matrix at five sites; a much higher concentration (48 micrograms/g) was detected in the sample from the urban environment. The remarkable PAH level increase at this site was mostly accounted for by the concurrent, apparent increase of EOM contamination as PAH concentration was seen to reach 32 micrograms/mg of EOM from < 1 microgram/mg at the five remaining sites. Mutagenicity assays with Salmonella typhimurium strains TA98 and TA100 of marine sediment organic extracts also highlighted a distinct activity in the sample from the urban site. Further fractionation and analysis of this extract pointed to PAHs as the main mutagenic component present in the sediment matrix, possibly accounting for up to approximately 70-80% of the entire mutagenic potential detected.

Toxic PCB congeners and organochlorine pesticides in Italian human milk.

Human milk from four major Italian cities was analyzed for individual congeners of polychlorinated biphenyls (PCB), DDT, DDE, hexachlorobenzene, and beta-hexachlorocyclohexane. Minimum and maximum concentrations in milk from individual mothers for most compounds ranged between one order of magnitude below and above the mean value of all mothers. Good agreements were found between results from pooled samples and mean values of individual samples. No statistically significant difference between cities was found and the levels in milk from Italian mothers did not differ significantly from published levels from other parts of the world. Principal component analyses revealed that the PCB congener distribution pattern was very similar in all mothers, independent of location. Average concentrations in milk from the four cities were 19(+/- 5) micrograms liter-1 total PCB or 3.2(+/- 0.8) ng liter-1 toxicity equivalents according to the most conservative TCDD toxicity equivalent factors of PCBs proposed in the literature, 70(+/- 18) micrograms liter-1 DDE, 4.5(+/- 1.2) micrograms liter-1 DDT, 5.6(+/- 1.9) micrograms liter-1 HCB, and 4.4(+/- 1.7) micrograms liter-1 beta-hexachlorocyclohexane.

Levels of polychlorobiphenyls (PCBs), polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs) in human milk.

The design and results of a WHO-coordinated study on the assessment of PCDDs and PCDFs in human milk are presented. Factors affecting levels of these contaminants are discussed and the protocol of the study is illustrated together with a summary of milk collection requirements and of the analytical method. Results of both quality control and field studies are summarized and discussed. Conversion of analytical findings into 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) "toxicity equivalence" (TE) units is also illustrated together with risk assessment issues based on the results of field studies.