The relationship between dioxins and salivary steroid hormones in Vietnamese primiparae

Ho Dung Manh,Hideaki Nakagawa,Seijiro Honma,Shoko Maruzeni,Sun Xianliang,Nguyen Ngoc Hung,Pham The Tai,Dao Van Tung,Madoca Nakano,Le Ke Son,Muneko Nishijo,Dang Duc Nhu,Teruhiko Kido,Hiroyuki Suzuki,Nguyen Hoang Viet,Rie Okamoto

doi:10.1007/s12199-012-0310-x

Abstract

Nearly 40years after Agent Orange was last sprayed, we conducted a cross-sectional study to evaluate the impact of dioxin exposure on salivary hormones in Vietnamese primiparae. Our previous studies found higher levels of salivary cortisol and cortisone in one of the most highly dioxin-contaminated areas, known as a "hot-spot", than in a non-exposed area. As a result, we suggested that further research with a larger number of participants would be needed to confirm whether dioxin affects steroid hormone levels in Vietnamese primiparae. The concentration of steroid hormones in saliva was determined by liquid chromatography (electrospray ionization tandem mass spectrometry), whereas the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in breast milk were determined by gas chromatography-high resolution mass spectrometry, for a sample of the population from a "hot-spot" (n=16) and a non-exposed area (n=10). All subjects were aged between 20 and 30years and had children aged between 4 and 16weeks. The mean toxic equivalence of PCDDs, PCDFs and PCDDs+PCDFs in breast milk in the hot-spot area was found to be significantly higher than in the non-exposed area (p<0.001). Likewise, salivary cortisol, cortisone and dehydroepiandrosterone (DHEA) levels were significantly higher in the hotspot area than in the non-exposed area (p<0.05). As a result, herein we report, for the first time, that salivary DHEA levels in primiparae are higher in a hot-spot than in a non-exposed area, and that this may be the result of dioxin exposure. Our findings highlight the long-term effects of Agent Orange/dioxin on steroid hormones in Vietnamese primiparae in the post-war period.

Highlights

We suggested that further research with a larger number of participants would be needed to confirm whether dioxin affects steroid hormone levels in Vietnamese primiparae
The concentration of steroid hormones in saliva was determined by liquid chromatography, whereas the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in breast milk were determined by gas chromatography-high resolution mass spectrometry, for a sample of the population from a ‘‘hot-spot’’ (n = 16) and a non-exposed area (n = 10)
Salivary cortisol, cortisone and dehydroepiandrosterone (DHEA) levels were significantly higher in the hotspot area than in the nonexposed area (p \ 0.05)

Summary

Introduction

There is growing concern regarding the adverse health effects posed by endocrine disrupting chemicals (EDCs) in the environment that may interfere with hormone biosynthesis and metabolism, thereby disrupting normal homeostasis [1, 2]. Especially polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs), are environmentally persistent organic pollutants (POPs) generated by industrial and domestic waste-incineration processes and during herbicide manufacture. Due to their high lipophilicity, dioxins tend to accumulate in fatty tissue. Breast milk samples have been found to contain very high levels of these compounds and have been used to monitor dioxin exposure in humans [3]

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Results

Conclusion