Measurement of Non-Persistent and Persistent Pesticides in Human Milk at Two Time Points And Relationships With Maternal and Child Biomarkers Measured in Blood and Urine

摘要

The presence of persistent pesticides in human milk, their relationships with biomarkers of exposure measured in other biological matrices, and the changes over time have been widely reported. Yet, no studies have determined these relationships for non-persistent pesticides. Understanding these relationships may help determine potential lactational exposures to children. We used gas chromatography-tandem mass spectrometry to measure 25 pesticides including organophosphates, pyrethroids, organochlorines, carbamates and a triazine in human milk samples from women residing in an agricultural region of CA who were participants of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS). Milk samples (n=52) were collected near delivery (DL) and repeat samples were collected six months postpartum (6M) in 27 women. Chlorpyrifos, DDE, DDT, and hexachlorobenzene were measured in maternal and cord blood collected from mothers at DL; OP metabolites were measured in urine collected from mothers at DL and children at 6M. Two non-persistent pesticides, chlorpyrifos and atrazine, and six persistent pesticides, o,p'-DDE, p,p'-DDE, o,p'-DDT, p,p'-dicofol, heptachlor epoxide, and hexachlorobenzene, had detection frequencies ＞50% in milk at both time points. Preliminary analyses showed that except for chlorpyrifos and o,p'-DDT these compounds were statistically significantly correlated at both time points; concentrations were generally lower at 6M than DL. Chlorpyrifos in milk was not correlated with markers in maternal or child blood or urine. In contrast, p,p'-DDE was highly correlated (r＞0.98) between milk, and maternal and cord blood. Pesticides were detected in human milk, indicating the potential for direct exposures to neonates and young children. Although concentrations of persistent pesticides may be predictable over time and in various biological matrices, there were no consistent patterns seen with the non-persistent pesticide chlorpyrifos.