Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakhstan: sources of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposures in an agricultural region of southern Kazakhstan.

Abstract

High levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; up to 208 pg/g fat) were measured in samples of breast milk collected in 1997 from 64 donors [41 first-time mothers (primiparae)] living on state farms in southern Kazakhstan. TCDD was the major contributor (70%) to the toxic equivalents, matching the congener patterns found in breast milk and serum samples collected in 1994 and 1996 from donors in nearby villages. The highest TCDD levels were found in state farms adjacent to a reservoir (zone A), which receives agricultural runoff from cotton fields. TCDD levels in zone A were significantly higher than levels in a region more distant (zone B; > 10 miles) from the reservoir (zone A: mean 53 pg/g, n = 17; zone B: mean 21 pg/g, n = 24; p = 0.0017). Levels of TCDD in breast milk and animal-derived foodstuffs were 10 times U.S. levels. Body burden and dietary data suggest that exposures to TCDD are chronic, environmental, and long term and may be related to the use of chemicals in cotton agriculture. The data suggest that the most likely source is the use of cotton defoliants contaminated with TCDD, and the most likely pathway for human exposure is via the consumption of contaminated foodstuffs.ImagesFigure 1Figure 2Figure 3

Levels of certain metals, organochlorine pesticides and dioxins in cord blood, maternal blood, human milk and some commonly used nutrients in the surroundings of the Aral Sea (Karakalpakstan, Republic of Uzbekistan)

“…One of the most toxic congeners, 2,3,7,8-TCDD, dominated the total burden of milk TEQs in Karakalpakstan. This congener pattern is substantially different from observations in most industrialized regions, including Ukraine, but similar to those in Kazakhstan (27). The measured TEQ concentrations of 2,3,7,8-TCDD in Karakalpakstan and Kazakhstan are among the highest documented levels in the world, accounting 66-82% of the total TEQs.…”

The Triad Mother-Breast Milk-Infant as Predictor of Future Health: A Narrative Review

“…Vegetarian and vegan diets are associated with major risk of nutritional deficiencies compared to omnivorous one, but update evidences highlight that if adequately supplemented, vegetarian and vegan diets could be considered safe for mothers and the offspring health during pregnancy and lactation [ 9 , 149 , 150 ]. Plant-based diets have been reported to contain more folate, fiber, antioxidants, and carotenoids and less saturated fatty acids, protein, and cholesterol [ 151 ], on the other hand, a low content of essential micronutrients especially in terms of iron, zinc, vitamin B12 [ 152 ], vitamin D, omega-3 (n-3) fatty acids, calcium, and iodine has been described inn vegetarian diet [ 153 ]. For this reason, micronutrient deficiencies might not be underestimated [ 149 ].…”

An assessment of dioxin exposure across gestation and lactation using a PBPK model and new data from Seveso

“…For example, Weiss et al (2003) compared three different cohorts, each consisting of 12 women who were nursing their new child; however the samples were pooled within each cohort so no individual data were available. Hooper et al (1999) suggested that the TCDD off-loading rates from two nursing mothers were between 4 and 5 pg/g of lipid per month of nursing (Hooper et al 1999). Although this finding suggests that nursing is a significant route of elimination, there are only two time points with measured TCDD concentrations, with the first in blood and the second in milk.…”