Levels of persistent organic pollutants in human milk in two Chinese coastal cities, Tianjin and Yantai: Influence of fish consumption

In 2006–2007, we collected human milk from 60 and 48 donors in the Chinese coastal cities of Tianjin and Yantai, respectively, in accordance with the WHO/UNEP global milk survey. We determined the concentrations of organochlorine pesticides by GC/MS/MS and dioxins by XDS-CALUX bioassay in the individual milk specimens. The geometric mean concentrations (GMs) of β-HCH (586.7 ng g−1 fat), total DDTs (855.9 ng g−1 fat), and dl-PCBs (4.4 pg CALUX-TEQ g−1 fat) in the milk from Yantai were higher than those from Tianjin (254.4 ng g-1 fat, 654.7 ng g−1 fat, 1.9 pg CALUX-TEQ g−1 fat, respectively). However, the GMs of HCB (41.1 ng g−1 fat) and PCDD/Fs (13.1 pg CALUX-TEQ g−1 fat) from Tianjin were higher than those from Yantai (15.7 ng g−1 fat, 9.9 pg CALUX-TEQ g−1 fat). The low ratios of DDT/(DDE+DDD) in milk from both areas suggested that past exposure contributed to the total DDTs body burden. The dl-PCBs body burden in the high sea fish intake group was higher than that in the low intake group, both with and without adjustments for potential influencing factors. For β-HCH, a marginal P value (P = 0.063) was observed between high and low sea fish consumption groups after adjusting for potential influencing factors. Donors in the high freshwater fish group showed higher PCDD/Fs and HCB levels than those in the low intake group, both with and without adjustments. Further monitoring studies of POPs contamination in human milk and foods are needed in China.