Residues of Polycyclic Aromatic Hydrocarbons in Breast Milk Collected from Jinhua (China) and the Influence of Exercise Habit: Levels and the Potential Health Effects

Breast milk is one of the best biological media to identify the pollutant exposure and the associated health risk. This study investigated the residues of 16 polycyclic aromatic hydrocarbons (PAHs) in breast milk of the general population from Jinhua, China. The potential influencing factors as well as the potential health effects on infants and mothers were analyzed. Results shows that only four of the 16 PAH species were detectable, and their mean concentrations were ranked as naphthalene (52.4 ng/g lipid) > phenanthrene (38.6 ng/g lipid) > fluoranthene (4.5 ng/g lipid) > pyrene (1.4 ng/g lipid). The average level of total PAHs was 97.0 ng/g lipid, which was lower when compared to other areas and countries. The statistical analysis showed that parity, especially the exercise habit was the key factor influencing PAH residue in breast milk. Women with first birth tended to have higher PAH levels. Frequent physical exercising can lower down PAH levels, reduce PAHs detection rate, and decrease PAH species in breast milk. The estimated daily intake of PAHs for infants through breast milk was 0.262 [not detectable (ND)-1.008] ng/kg bwt/day BaP in often-exercise group, and 0.544 (ND-1.568) ng/kg bwt/day BaP in seldom-exercise group, which were well below the regulated values set by UK, USEPA, JECFA and EFSA. However, the cancer risk of infants in the seldom-exercise group (1.9 x 10(-6)) exceeded the acceptable level of 10(-6). Correlation analysis also revealed that PAHs residues in mother have no potential adverse effects on fetal growth, but may be linked with dysmenorrhea of mother. The results of this study provided valuable knowledge for mitigating the potential hazards of PAHs exposure to mothers and infants, and can serve as a fundamental basis for devising effective prevention and control measures aimed at minimizing PAHs exposure.