Endocrine Disrupters ECD

The endocrine (hormonal) system is a network of glands and receptors that function to regulate a number of key body-functions, like growth, development, and maturation, as well as the operation of various organs in the bodies of vertebrates. In short, the endocrine system provides the key communication and control link between the nervous system and all body functions, through the secretion of hormones. 

There are a number of chemicals that can disrupt normal functioning of the endocrine system, called endocrine disrupters (ECD). An ECD usually either mimics or blocks hormones and hence disrupts the body s normal functions, after its absorption by the body. 

The effects of ECD on developing organisms are of greatest interest, because the disruptive (organisational) effects in this case are shown to be permanent and irreversible, while ECD exposure of adults can be reversible [21]. 

A wide range of organic chemicals (mostly synthetics, including certain additives and plasticisers - snch as phthalates, bisphenol A, and nonylphenols - all used as additives in plastics) are snspected potential ECD agents. The list of ECD also inclndes pesticides (such as DDT, which is banned) and many industrial and consnmer products - such as, liquid soaps, shampoos, conditioners, and hair colours - that contain alkylphenol ethoxylates (APE, which have been replaced by the more expensive, but much safer, alcohol ethoxylates). In addition, there are polychlorinated biphenyls (PCB), dioxins, certain preservatives and metal ions, and even certain treated woods suspected as endocrine disruption agents in hnmans based on (limited) animal stndies, (see Table 2.2). Synthetic oestrogens are the focns of cnrrent concern for ECD there are certain natnral 

Disruption of the endocrine system is believed to occur in the following ways  

As outlined previously, ECD are chemicals that can cause hormonally related diseases and dysfunction that can be effective at very low levels (even at parts per trillion levels 

The mechanisms of ECD is poorly understood and specific end points or effects of ECD are not clearly defined yet, and there is still much to be understood and to be explored about its role. 

There are four groups of chemicals that are labelled as suspected ECD Agents  

Plastics contain various additives, such as phthalates, bisphenol-A, and nonylphenols, usually present as plasticisers used to make them flexible and dnrable. They can leach out into liquids as well as evaporate into the gas phase and can be inhaled. Increase in temperature usually speeds all of these (which is why microwaving foods in plastic is discouraged). Oestrogenic butyl benzyl phthalate is fonnd in vinyl floor tiles, adhesives. 

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Other VOC such as Aliphatic hydrocarbons - e.g., mainly hexane Halogenated aliphatic hydrocarbons - e.g., mainly chloroform Aliphatic alcohols - e.g., methanol, ethanol and 1-butanol Glycols and glycol ethers Aromatic hydrocarbons - e.g., mainly benzene, toluene and xylene Various endocrine disrupters (ECD) (certain additives and plasticisers) Emitting from carpets, flooring materials, paints, furniture. Eound in natural and synthetic resins, paints and lacquers Eound in paints, adhesives and pesticides... 

Endocrine Disrupters (ECD) and Some Suspected ECD Agents Indoors... 

Table 12.1 presents some toxics that can be found indoors originating from construction materials, and in Table 12.2, their effects on humans are presented, followed by some more information about radon and endocrine disrupters (ECD). 

In 1996, the Environmental Protection Agency s (EPA) Office of Research and Development (ORD) [15] identified endocrine disruption as one of its top six research priorities. ORD s research program plan published in 1998, has three long-term goals in ECD research [11]. 

As outlined in Chapter 2, ECD are chemicals that can cause hormonal related diseases and dysfunctions that can be effective even at very low levels (at parts per trillion, levels at which most chemicals have never been tested). ECD became a significant focus of environmental science and medicine in recent years because of its critical importance in heath. A wide range of chemicals, both natural compounds (phytoestrogens) and some synthetic chemicals (including polychlorinated biphenyls (PCB), dioxins, certain preservatives and metal ions, even certain woods) are all suspected of being capable of endocrine disruption in humans. 

Existing EU legislation accounts for ECD effects on reproduction and related diseases, such as cancer, but not on any other disruption to the endocrine system. 

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