Levels Of Endocrine Disruptors Research Articles

Impact of the Environment on Male Sexual Health

Erectile dysfunction is a common condition with multiple risk factors. There is a growing body of evidence that endocrine disruptors in the environment can impact sexual health. Endocrine disruptors can be both natural and synthetic compounds. We will review the pertinent literature on phytoestrogens, heavy metals, bisphenol A, polychlorinated biphenyl, dichlorodiphenyltrichloroethane (DDT), passive smoking, and drinking water contaminants. While animal studies support estrogenic effects of these compounds that can lead to reproductive and sexual dysfunction, the association in human studies remains weak. Thus, further research in this area is needed and safe levels of endocrine disruptors in the environment must be established.

Determination of Endocrine Disruptors in Environmental Water by Single-Drop Microextraction and High-Performance Liquid Chromatography

Using single-drop microextraction followed by high performance liquid chromatography, an effective method for the rapid extraction for endocrine disruptors, including estrogens and alkylphenols, was developed. Factors that influenced the extraction efficiency, such as hydrogen bonding, hydrophobic property, polarity, and van der Waals forces, were evaluated in detail. The results indicated that bisphenol A and estrogens were extracted effectively by the solvents with hydrogen bond acceptors and higher polarity; alkylphenols preferred solvents that could supply strong van der Waals forces or possessed π-π stacking structures and superior hydrophobicity. The optimum extraction conditions were determined, including extraction time, pH, and salt effects. Under the optimized conditions, high extraction factors (≥147) were achieved. Limits of detection for the endocrine disruptors were between 0.33 and 0.67 µg L−1. The method strategy is well suited for the determination of trace levels of endocrine disruptors in environmental water.

The association between some endocrine disruptors and hypospadias in biological samples

Hypospadias is a birth defect found in boys in which the urinary tract opening is not at the tip of the penis. The etiology of hypospadias is still unidentified, but endocrine disruptors are considered as one possible cause of hypospadias. In this study, target endocrine disruptor compounds were established for an assay. The target compounds included 5 phthalates (di-(2-ethylhexyl)phthalate (DEHP), di-n-butyl-phthalate (DBP), mono-(2- ethylhexyl) phthalate (MEHP), mono-n-butyl-phthalate (MBP) and phthalic acid (PA)), 2 alkylphenols (n-nonylphenol (n-NP) and t-octylphenol (t-OP)) and bisphenol A. The association between these 8 endocrine disruptors and hypospadias was studied. The levels of endocrine disruptors in the urine and plasma of a control group were compared with those of a patient group. DEHP (P = 0.006) and n-NP (P = 7.26e-6) in the urine samples and PA (P = 0.009) and BPA (P = 7.22e-10) in the plasma samples showed a significant association with hypospadias. The levels of endocrine disruptors in the urine and plasma of the mothers were also compared to those of the patients to investigate the metastasis of the endocrine disruptors from the mother. These levels did not, however, show a relationship with hypospadias (R2 = 0.001–0.563).

Determination of 4-nonylphenol in carp blood samples by solid phase extraction and chromatographic techniques

In this study, selective methods were developed for isolation, purification, separation and determination of 4-nonylphenol (4NP) in biological samples. Several methods such as high-performance liquid chromatography (HPLC) with fluorescence and diode array detection and gas chromatography coupled to mass spectromotry (GC-MS) are described for the simultaneous determination of 4NP. The nonylphenols in the plasma of fish were extracted through solid phase process by using octadecyl, polymeric and octadecyl endcapping sorbents. The average recoveries in plasma samples spiked with 4NP of levels 1 µg mL−1 were between 80–95% using added surrogate standards. The aim of this study was to determine whether trace amounts of 4NP in fish plasma samples could be detected by solid phase extraction and chromatographic methods (HPLC, GC-MS). This technique of monitoring the levels of endocrine-disruptors in plasma samples is consistent, reliable as well as inexpensive.

Exposure levels of endocrine disruptors in Nordic Countries

A number of different xenobiotic compounds have shown estrogenic, anti‐androgenic, or “dioxin‐like” (Ah‐receptor agonism) activities in vitro as well as adverse reproductive effects in toxicological animal studies. Although human evidence is at best weak for a few compounds, and for most compounds is absent, they have been implicated as potential endocrine disruptors affecting human male reproduction. According to their metabolic properties in mammals these compounds may be divided into two groups. Compounds such as the polychlorinated dibenzo‐p‐dioxins (PCDDs) and dibenzofurans (PCDFs), polychlorinated biphenyl (PCBs), and a number of organochlorine pesticides, i.e. DDT/DDE, HCHs, HCB, dieldrin, and toxaphenes, are highly resistant to metabolic degradation in the food chains and accumulate in the human body. Because of this property compounds belonging this group are of the greatest concern. It is not the low daily intake, but the total body burden of the pregnant woman achieved over time that is of importance. Control of emissions to the environment and restrictions in use have significantly decreased human intakes during the last 15–20 years. A number of other compounds, such as bisphenol A, certain phthalates, alkylphenols, and some pesticides in current use have also shown various effects in vitro. These compounds are readily metabolised by mammals and do not accumulate in humans and in most cases fairly high doses are required to produce reproductive effects in animal studies. Most of these compounds have been included in the Danish Food Surveillance System since the early 1980s, and their intakes have been estimated based on Danish Food Consumption Data. For PCDDs, PCDFs and dioxin‐like PCBs a recent EU SCOOP project have provided up‐dated estimates of intakes in various European countries. The presentation will discuss the significance of the human intake levels in relation to the toxicological properties of these compounds. From this exercise it seems apparent that the dioxins are among the best candidates for having produced endocrine effects in humans, in particular at the much higher exposure levels that were seen 15 or more years ago.

An Approach to the Development of Quantitative Models to Assess the Effects of Exposure to Environmentally Relevant Levels of Endocrine Disruptors on Homeostasis in Adults

An Approach to the Development of Quantitative Models to Assess the Effects of Exposure to Environmentally Relevant Levels of Endocrine Disruptors on Homeostasis in Adults