Endocrine disruptor compounds

Liu C, Zachara JM, Smith SC, McKinley JP, Ainsworth CC (2003) Desorption kinetics of radiocesium from subsurface sediments at Hanford Site USA. Geochim Cosmochim Acta 67 2893-2912 Loffredo E, Senesi N (2006) Eate of anthropogenic organic pollutants in soils with emphasis on adsorption/desorption processes of endocrine disruptor compounds. Pure App Chem 78 947-961... 

Xenoestrogens, exhibiting a wide molecular diversity, are found in a number of cosmetic products, such as plasticizers, perfume fixatives, and solvents (e.g., dibutyl phthalate), industrial chemicals and pollutants such as insecticides (e.g., methoxychlor, DDT, and DDE), epoxy resins, and polycarbonate (e.g., bisphenol A), and herbicides (e.g., simazine). This group of chemicals has been classified as environmental endocrine disruptor compounds (EDCs), defined as exogenous agents that interfere with the synthesis, transport, binding, action, or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development, and/or behavior. A list of representative chemicals is shown in Table 1 based on commercial usage. 

In recent years the interest of environmental analytical chemistry was turned to the so-called emerging contaminants or new unregulated contaminants including pharmaceuticals, endocrine disruptors, detergents, personal care products, plasticizers, flame retardants, gasoline additives, etc. These compounds are released continuously to the environment and can be found in water, sediments, soils, etc. In most of the cases they are found at trace level concentration (ng/L) therefore, powerful analytical capabilities are required for their determination. 

Endocrine disruptors apparently affect all nuclear receptors. Thus, a notable increment in impotence, alterations of the libido and of oligospermia in workers exposed to pesticides has been described. These alterations are due to the action of some compounds with estrogen-mimetic action and to their interaction with the androgen receptor. Additionally, alterations of thyroid function have been detected in rats exposed to dioxin and other toxic agents,... 

But if we take into account the emerging pollutants and compounds, the choice of which is guided by environmental considerations (mainly risks for health), then surfactants, endocrine disruptors, pesticides, other industrial organics (PAH, aromatic amines,...) or inorganics (sulphides, arsenic,...) and microbiological indicators (pathogens) must also be considered. 

Endocrine disruptors are nowadays considered among the most important emerging pollutants in wastewater, but they are not actually monitored on-line. A recent study [48] described the implementation of a broad-spectrum analytical scheme for the screening of more than 200 compounds (endocrine disruptors, pharmaceutical compounds,...) in urban wastewater. For other specific organic compounds, a study concerning the improvement of immunoassays with a solid-phase extraction (SPE) membrane was reported for the on-site detection in soils and water of energetic materials (i.e. explosives) [49], but unfortunately it was not really tested for wastewater. 

Recent studies, including the use of Microtox and ToxAlert test kits [55,56], were carried out for the determination of the toxicity of some non-ionic surfactants and other compounds (aromatic hydrocarbons, endocrine disruptors) before implementation on raw and treated wastewater, followed by the identification and quantification of polar organic cytotoxic substances for samples with more than 20% inhibition. Furthermore, the study of their contribution to the total toxicity was obtained using sequential solid-phase extraction (SSPE) before liquid chromatography-mass spectrometry (LC-MS) detection. This combined procedure allows one to focus only on samples containing toxic substances. 

The hypothesis that environmental endocrine disruptors may contribute to diseases of the male reproductive tract has spurred considerable research on this area, with a particular emphasis on changes that have occurred over time. There are no apparent global changes in sperm counts and fertility, rates of hypospadias and cryptorchidism, and birth sex ratios. Testicular cancer is increasing in most countries, but it is not correlated with other indicators of male reproductive capacity. Moreover, testicular cancer is increasing while DDE and other POPs are decreasing, suggesting that exposure to these compounds is not linked to testicular cancer. 

At that time (1994-96), I had research support for a project on estrogenic compounds funded by the Chemical Manufacturers Association (CMA) my only official contact with the association was Ann Mason, Director of Scientific and Regulatory Affairs (Chlorine Chemistry Council, CMA), who asked for a yearly report. My opinions on the endocrine disruptor hypothesis have been based on analysis of scientific publications and have been consistent prior to, during, and after the research (not personal) support from the CMA. 

Mindless personal attacks by individuals whom you do not know are disappointing, particularly in light of results of continuing studies that have not identified linkages between exposure to endocrine disruptors and human disease. I have always acknowledged the adverse impact of environmental endocrine-active compounds on fish and wildlife populations in some areas, but have questioned their impact on human health. Scientific studies published in the past six to eight years have addressed many of the critical issues associated with endocrine disruptors and human health, and extensive references to these papers have been intentionally included in this chapter. Results of the more recent studies indicate that initial concerns regarding hypothesized endocrine disruptor-induced human problems may not be justified. 

Taniyasu S, Yamashita N, Pettrick G, Kannan K, Gamo T, Lam P, Giesy JP (2003b) Perfluorooctane Sulfonate (PFOS) and Related Compounds in Open Ocean Water. 6th Annual Meeting of Japan Society of Endocrine Disruptors Research, December,... 

Table 1 Relative accumulation of endocrine disruptors and harmful compounds by UV-irradiated DNA films (I), DNA-immobilized porous glass beads (II), and DNA-...

Stakeholders invited to provide listings of substances of concern drivers might be compounds detected in industrial discharges awareness of international concerns (e.g., endocrine disruptors, pharmaceuticals) inputs from industry, NGOs, public... 

Concerns over their potential to function as endocrine disruptors led to a Japanese study on the levels of alkylphenols in 60 rubber products. Such compounds are used as starting materials in the manufacture of a number of mbber additives, particularly oligomeric phenolic antioxidants. The work concentrated on four compounds p-/er/.butyl phenol (PTBP), p-/er/.octylphenol... 

Endocrine disruption is a newly discovered mode of action and has encouraged a great deal of research. Compared to some of the other mechanisms described in this chapter, endocrine disruption is more subtle with alterations in reproductive physiology and morphology often being the effects, instead of death. Because of the hormone-like activity, these compounds can have identifiable effects at very low concentrations. It is not yet clear what the overall importance of endocrine disruptors are in creating environmental impacts compared to other modes of action. 

Recently, the hazardous effects of endocrine disruptors (environmental hormones) such as bisphenol A and nonylphenol on the human body have been reported, and led to the initiation of many studies concerning the detection and structural determination of these compounds present in tiny amounts [57]. As one of the QSAR analyses of environmental hormones, the relationship between their biological activity and chemical hardness has been reported [16]. By applying these analytical methods, the molecular toxicity and estrogen-like activity of environmental hormones have been found... 

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