Introducing of modeling techniques in the research of POPs in breast milk - A pilot study.

This study used advanced statistical and machine learning methods to investigate organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in breast milk, assuming that in a complex biological mixture, the pollutants emitted from the same source or with similar properties are statistically interrelated and possibly exhibit non-linear dynamics. The elaborated analyses such as Unmix source apportionment characterized individual source groups, while guided regularized random forest indicated the pollutant dependence on the ortho-chlorine atom attached to the congener's phenyl ring and mother's age. Mutual associations among PCBs were further discussed, but the results implied they were mostly not related to child delivery. PCB congeners -153, -180, -170, -118, -156, -105, and -138 appeared to be compounds of the outmost importance for mutual prediction with reference to their interrelations regarding chemical structure and metabolic processes in the mother's body. Finally, machine learning methods, which provided prediction relative errors lower than 30% and correlation coefficients higher than 0.90, suggested a possible strong non-linear relationship among the pollutants and consequently, the complexity of their pathways in the breast milk.

Persistent Organochlorine Pollutants in Placentas Sampled from Women in Croatia and an Evaluation of Their DNA Damaging Potential In Vitro.

This study investigated the levels and distribution of 17 polychlorinated biphenyls (PCBs) and organochlorine pesticides (HCB, α-HCH, ß-HCH, γ-HCH, p,p'-DDE, p,p'-DDD, and p,p'-DDT) in placenta samples from women living in the coastal area of Croatia. During November 2012 to February 2013, 51 placenta samples were collected from healthy mothers. This study presents the first report about Croatian placenta samples. Each of the analysed compounds were found in all of the samples; all of the maximum values were < 1 ng g-1 w.w., and the highest median value found for PCB-28 was 11.2 pg g-1 w.w. PCBs and organochlorine pesticide (OCPs) present in placenta samples were tested for their genotoxic potential using the alkaline comet assay. The alkaline comet assay is one of the most reliable methods in assessing the DNA lesions that occurs in direct interaction of a chemical and the genome. The detected levels of PCBs and OCPs in the placenta did not pose a significant risk to the children's DNA during embryonic and foetal growth following short-term exposure. PCB and OCP concentrations in the placenta samples did not induce any significant primary damage to DNA in terms of DNA strand breaks and changes in the primary chemical structure, which could be detected by the alkaline comet assay.