Prenatal mercury exposure and postnatal outcome: clinical case report and analysis

Effects of environmental contaminants on fertility and reproductive health

Recent research indicates that the human infertility rate is increasing. Although various reasons have been hypothesized for the growing infertility rate, environmental contaminants are potentially important causal agents associated with this change. Chemical contaminants are widespread throughout our environment and human exposure is virtually unavoidable. The overall contribution of environmental exposure to infertility is unknown, but studies involving occupational exposure, together with results from animal experiments, suggest that environmental contaminants may adversely affect fertility. We reviewed the adverse effects of environmental exposure on fertility and related reproductive outcomes. Environmental contaminants covered in this review include heavy metals, organic solvents, pesticides and endocrine disrupting chemicals. It is hoped that this review will highlight the need for further research in this area.

Contaminación por mercurio de leche materna de madres lactantes de municipios de Antioquia con explotación minera de oro

Introducción. La leche materna es esencial para el desarrollo del ser humano, pero puede contener sustancias tóxicas provenientes de la contaminación ambiental, especialmente en las áreas mineras.Objetivo. Determinar la prevalencia de la contaminación con mercurio de la leche materna de mujeres lactantes residentes en los municipios con explotación minera de oro.Materiales y métodos. Se hizo un estudio transversal de 150 madres lactantes de cuatro municipios mineros de Antioquia (El Bagre, Segovia, Remedios y Zaragoza), a quienes se les hizo una encuesta sobre factores sociodemográficos, ocupacionales y ambientales relacionados con el mercurio, y se les tomaron muestras de leche materna, de orina y de cabello. Se calculó el promedio de la concentración de mercurio y las prevalencias municipales de contaminación.Resultados. El promedio de la concentración de mercurio en la leche materna fue de 2,5 (± desviación estándar 9,2) μg/L. La prevalencia de muestras de leche materna con niveles altos de mercurio fue de 11,7 %.Conclusión. En este estudio se evidencia un grave problema en las regiones mineras auríferas de Antioquia por el efecto de la contaminación con mercurio en sectores de la población más vulnerable.

Umbilical cord blood mercury levels in China

Mercury (Hg) is a well-known neurotoxicant. Hg exposure at high levels can harm individuals of all ages. Even low level exposure to Hg can damage the brain of fetuses and young children, and affect their central nervous system and cognitive development. The aims of our study were to measure total Hg levels in infant umbilical cord blood and to investigate the risk factors associated with total Hg cord blood levels in various cities in China. Our goal was to provide clues for the prevention of Hg exposure in utero. The results indicated that the average cord blood mercury levels (CBMLs) were (1.81 +/- 1.93) microg/L, which were lower than those found in most previous studies. The concentrations also differed according to geographic region. The CBMLs were not only associated with family economic and living conditions, but also with diet in pregnant women, especially the intake of marine fish, shellfish, poultry, formula milk and fruits.

Effects of mercury on the steroidogenesis of human adrenocarcinoma (NCI-H295R) cell line

In this study the NCI-H295R human adrenocortical carcinoma cell line was used as an in vitro biological model to study the effect of mercury (HgCl(2)) on the steroidogenesis. The cells were cultured for 48 h with addition of 1.0; 5.0; 25; 50 or 100 μM of HgCl(2) and compared to control. Cell viability was measured by the MTT (metabolic activity) assay estimation for the mitochondria structural integrity. Quantification of testosterone and progesterone directly from aliquots of the medium was performed by enzyme linked immunosorbent assay (ELISA). Concentration-dependent depression in testosterone production was detected particularly for higher concentration of Hg(2+). Progesterone production was also decreased, but at the lower concentrations (1.0 and 5.0 μM) of Hg(2+) this decline was lower compared to depression of testosterone. The cell viability significantly decreased at 25 μM and higher concentration of Hg(2+). However, at 25 μM Hg(2+) exposure the cell viability remained relatively high (> 80%). Results of the study indicate dose-dependent decreases in both testosterone and progesterone production of H295R cell culture following a 48 h in vitro HgCl(2) exposure. The results suggest that Hg has detrimental effects on steroid hormone synthesis also at very low concentrations and consecutively on reproductive physiology.

In vitro study on the effects of lead and mercury on porcine ovarian granulosa cells

The heavy metals lead (Pb) and mercury (Hg) pose potential risks to sustainability of environment and thus to our future generations. General objective of this in vitro study was to examine the secretory activity of porcine ovarian granulosa cells after Pb and Hg administration and to outline the potential intracellular mediators of its effects. For this purpose, release of insulin-like growth factor I (IGF-I) and steroid hormone progesterone (P(4)), expression of proliferation- related (cyclin B1) and apoptosis-related (caspase-3) peptides was examined in porcine ovarian granulosa cells after heavy metals administration. Obtained data indicate Pb-induced inhibition of IGF-I release at lower doses (0.063 mg/mL and 0.046 mg/mL) by ovarian granulosa cells. However, P(4) release was not influenced by Pb addition, while the expression of cyclin B1 and caspase-3 was induced by Pb addition. These results indicate that Pb can affect the pathway of proliferation and apoptosis of porcine ovarian granulosa cells through intracellular substances such as cyclin B1 and caspase-3. On the other hand, the P(4) release by ovarian granulosa cells of pregnant gilts was stimulated by experimental Pb administration at doses of 0.25 mg/mL and 0.063 mg/mL and experimental Hg administration at doses 0.25 mg/mL and 0.083 mg/mL. P(4) release by ovarian cells of pregnant gilts was not influenced by a combinatory dose of FSH (1.0 ng/mL) + Pb (0.083 mg/mL) + Hg (0.083 mg/mL) but it was inhibited by experimental administration of FSH (10 ng/mL) + Pb (0.25 ng/mL) + Hg (0.25 ng/mL). Possible involvement of heavy metals - Pb and Hg and pituitary hormone FSH, in the regulation of P(4) release by porcine ovarian granulosa cells of pregnant gilts was noted. Data obtained from in vitro studies suggest the dose dependent association of heavy metals administration with the hormonal release by porcine ovarian granulosa cells. This association also depended on pregnancy of the gilts.