Perinatal Exposure to Low Doses of Dioxin Can Permanently Impair Human Semen Quality

Abstract

BackgroundIn recent decades, young men in some industrialized areas have reportedly experienced a decrease in semen quality.ObjectiveWe examined effects of perinatal dioxin exposure on sperm quality and reproductive hormones.MethodsWe investigated sperm quality and hormone concentrations in 39 sons (mean age, 22.5 years) born between 1977 and 1984 to mothers exposed to dioxin after the accident in Seveso, Italy (1976), and 58 comparisons (mean age, 24.6 years) born to mothers exposed only to background dioxin. Maternal dioxin levels at conception were extrapolated from the concentrations measured in 1976 serum samples.ResultsThe 21 breast-fed sons whose exposed mothers had a median serum dioxin concentration as low as 19 ppt at conception had lower sperm concentration (36.3 vs. 86.3 million/mL; p = 0.002), total count (116.9 vs. 231.1; p = 0.02), progressive motility (35.8 vs. 44.2%; p = 0.03), and total motile count (38.7 vs. 98 million; p = 0.01) than did the 36 breast-fed comparisons. The 18 formula-fed exposed and the 22 formula-fed and 36 breast-fed comparisons (maternal dioxin background 10 ppt at conception) had no sperm-related differences. Follicle-stimulating hormone was higher in the breast-fed exposed group than in the breast-fed comparisons (4.1 vs. 2.63 IU/L; p = 0.03) or the formula-fed exposed (4.1 vs. 2.6 IU/L; p = 0.04), and inhibin B was lower (breast-fed exposed group, 70.2; breast-fed comparisons, 101.8 pg/mL, p = 0.01; formula-fed exposed, 99.9 pg/mL, p = 0.02).ConclusionsIn utero and lactational exposure of children to relatively low dioxin doses can permanently reduce sperm quality.

Histological and Transcriptomic Changes in Male Zebrafish Testes Due to Early Life Exposure to Low Level 2,3,7,8-Tetrachlorodibenzo-p-Dioxin

“…Previously, we used this model to identify transgenerational effects of dioxin (2,3,7,) on skeletal development, sex ratio, and reproductive capacity. Transgenerational inheritance of TCDD toxicity, notably decreased reproductive capacity, appears to be mediated through the male germ line.…”

Thyroid and growth hormone concentrations in 8-year-old children exposed <i>in utero</i> to dioxins and polychlorinated biphenyls

“…The dioxin-AHR/ARNT complex has been reported to interact with several transcription factors to directly or indirectly regulate various genes relating to the early development of the reproductive system and hormone production (Mocarelli et al, 2011). For instance, growth hormone gene expression has been found to be regulated by 2,3,7,8-tetrachlorodibenzo-p-dioxin in part through the AHR (Elango et al, 2006).…”

Effects of Chlorella Supplementation on Decreasing Concentrations of Dioxins in the Blood of Pregnant Japanese Women

“…The findings showed the effectiveness of daily intake of Chlorella from gestational week [16][17][18][19][20] until the day of delivery for lowering of maternal blood dioxin levels. As mentioned above, adverse health consequences from prenatal, perinatal and postnatal exposure to background levels of dioxins, including PCDDs and PCDFs, have been reported [5][6][7][8][9][10][11][12]. There is a positive relationship between dioxin concentration in the blood and that in cord blood, breast milk, and various tissues, including lung, liver, spleen, pancreas, kidney, mesentery fat, and subcutaneous fat [19][20][21][22].…”

“…In addition, perinatal and postnatal exposure to background levels of environmental dioxins and DL-PCBs exerts an adverse effect on thyroid hormone status [9,10] and on immune surveillance [11] in Japanese breast-fed infants. Finally, perinatal exposure of children to relatively low dioxin and DL-PCB doses can permanently reduce sperm quality [12].…”