Exposure and risk assessment of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) for primiparous mothers and breastfed infants in Penang, Malaysia

ABSTRACT

An average 50 ml breast milk samples were collected from 21 lactating primiparous mothers (range 25 to 45 years, mean 33 years), 4–8 weeks after delivery in Penang Island, Malaysia. The geometric mean concentration of the most toxic congeners, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) was 0.14 pg WHO₂₀₀₅-TEQ g⁻¹ zlipid. The most abundant congeners of PCDD/Fs were octachlorodibenzo-p-dioxin (OCDD) (5.9–75.4%), followed by 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (1,2,3,4,6,7,8-HpCDD) (1.1–30.7%). The geometric mean level of total dioxins and dl-PCBs was 2.2 pg WHO₂₀₀₅-TEQ g⁻¹ lipid, significantly lower than those in developed countries or highly contaminated areas. The total dioxins and dl-PCBs in pg WHO₂₀₀₅-TEQ levels in breast milk were significantly correlated with years of residence at potential contaminated site. The average daily intake of 11.8 pg WHO₂₀₀₅-TEQ kg⁻¹ body weight was estimated for a breastfed infant at 6 months of age. This demonstrates the exposure risk to infants, especially from Penang region, to these pollutants from human milk intake are potentially high during the lactation period.

GRAPHICAL ABSTRACT

KEYWORDS:

• Dioxins
• breastmilk
• primipara
• estimated daily intake

Acknowledgments

Sincere gratitude goes to all donor mothers, participants of this study, the management of child delivery centres and the Dioxins laboratories in Institute of Health Inspection and Testing, Hubei Provincial Center for Disease Control and Prevention, Wuhan, China. The authors also would like to thank Chuah Lucie for editing and proofreading the text.

Additional information

Funding

This project was supported by Universiti Sains Malaysia [RUI grant 1001/CAATS/812172] and Fundamental Research Grant Scheme (FRGS) [203/CRACUN/6711537].