madman
Super Moderator
Abstract
OBJECTIVE: Chemicals that disrupt the endocrine homeostasis of the human body, otherwise known as endocrine disruptors (EDCs), are found in the blood, urine, amniotic fluid, or adipose tissue. This paper presents the current knowledge about EDCs and the reproductive system.
MATERIALS AND METHODS: The article is an overview of the impact of EDCs and their mechanism of action, with particular emphasis on gonads, based on the information available on medical databases (PubMed, Web of Science, EMBASE and Google Scholar, EMBASE and Web of Science) until May 2021.
RESULTS: EDCs occur in everyday life, e.g., they are components of adhesives, brake fluids, and flame retardants; they are used in the production of polyvinyl chloride (PVC), plastic food boxes, pacifiers, medicines, cosmetics (bisphenol A, phthalates), hydraulic fluids, printing inks (polychlorinated biphenyls – PCBs), receipts (bisphenol A, BSA), and raincoats (phthalates); they are also a component of polyvinyl products (e.g. toys) (phthalates), air fresheners and cleaning agents (phthalates); moreover, they can be found in the smoke from burning wood (dioxins), and in soil or plants (pesticides). EDCs are part of our diet and can be found in vegetables, fruits, green tea, chocolate, and red wine (phytoestrogens). In addition to infertility, they can lead to premature puberty and even cause uterine and ovarian cancer. However, in men, they reduce testosterone levels, reduce the quality of sperm, and cause benign testicular tumors.
CONCLUSIONS: Therefore, this article submits that EDCs negatively affect our health, disrupting the functioning of the endocrine system, and particularly affecting the functioning of the gonads.
Introduction
Endocrine-disruptor chemicals/compounds (EDCs) are chemicals that disrupt the body’s hormonal homeostasis. They play an important role in the functioning of the endocrine system, including the hypothalamic-pituitary-gonadal axis (HPG axis). Some common and widely studied EDCs have a negative effect and a broad spectrum of activity on the endocrine system. These include: (1) plasticizers such as (a) bisphenol A (BPA) is used in the production of polycarbonates and epoxy resins with a very wide range of applications, and b) phthalates used in the production of phthalic varnishes and paints, adhesives, and laminates, and used as plasticizers; (2) polychlorinated biphenyls (PCBs) used as plasticizers, hydraulic fluids and lubricants, in the production of packaging, as a component of printing inks, as an additive to insecticides, adhesives, and plastics, and as an insulation material; (3) polybrominated diethyl ethers; (4) dioxins (a product of the incineration of municipal waste or volcanic eruptions); (5) pesticides (insecticides, herbicides and fungicides) used in the protection of plants, farm animals and food during storage and transport, in the paper and textile industry, in cosmetics; (6) phytoestrogens which are commonly found in our diet, e.g., some vegetables (soybeans, broccoli, onions, tomatoes), fruits, red wine, chocolate, and green tea1,2
The mechanism of action of EDCs is not fully understood. They may impair the functioning of the endocrine system2 . However, it is known that in the case of the female gonad, they may cause changes in the estrogen signaling pathways or interact with estrogen receptors (ER). Similarly, in the case of the male gonad, EDCs may interfere with natural hormones via androgen and its receptor3 . EDCs can act as agonists, mimicking the natural hormone by binding to and activating various hormone receptors (i.e., hydrocarbon receptor [AhR], ER, the pregnane X receptor [PXR, NR1I2], constitutive androstane receptor [CAR, NR1I3]). EDCs can bind to these receptors without activating them (antagonistic activity). Moreover, EDCs, especially in pesticides, can reduce the concentration of hormones by influencing their synthesis, transport, metabolism, and elimination, and interrupt critical cellular processes (Figure 1)4-7.
EDCs can lead to the development of uterine (BPA) and ovarian cancer (BPA), premature puberty (BPA, phthalates), and fertility disorders (BPA). In men, however, they reduce the sperm count (phthalates) and testosterone levels (phthalates) and cause benign testicular tumors (phthalates). Furthermore, EDCs reduce the quality of the sperm, which can result in the development of prostate cancer (BPA). The omnipresence of EDCs, which result in environmental pollution, can lead to many future diseases for which we do not yet have accurate knowledge. It has been demonstrated that some EDCs have thyrogenic, estrogenic, and antiandrogenic properties8. In an era of increasing infertility problems for both men and women, we would like to show any associations between EDCs and fertility. This review analyzes how EDCs influence human health, focusing mainly on the human reproductive system.
Plasticizers: (a) bisphenol A (BPA) and (b) phthalates
(a) Bisphenol A (BPA)
*Mechanistic and Human Studies
(b) Phthalates
*Mechanistic and Human Studies
Polychlorinated Biphenyls
*Human Study
Dioxins
*Mechanistic Studies
*Human Study
Pesticides
*Human Study
Phytoestrogens
*Mechanistic Studies
*Human Study
Limitations
One limitation of our study is that we do not have conclusive data to thoroughly analyze the effects of EDCs on gonads. Secondly, while the mechanism of action and impact of EDCs can be demonstrated in many animal studies, this becomes a significant problem in human reproductive health. Thirdly, longer follow-up is needed to determine how ECDs affect both male and female gonads.
Conclusions
As human beings, we are constantly exposed to many environmental chemical substances, including the many EDCs found in body fluids and tissues. Several studies indicate their additive or synergistic effects. Hence, their action may have unpredictable effects on humans. More and more reliable data indicates that EDCs have side effects on our health, even at low doses. While many epidemiological studies have previously focused mainly on people at risk of persistent exposure to EDCs due to their occupation or those affected by accidental exposure (Soveso, Italy), recent studies have suggested far-reaching effects of EDCs in the general population. The reproductive systems of both women and men are complex and require the proper structure and functioning of many organs, including the pituitary-gonadal axis. EDCs can interfere with reproduction by adversely affecting the organs of the female and male reproductive systems and/or their function.
It should be noted that the chemical industry is interested in results that have a positive effect on the industry itself, indicating that the produced chemical is safe for humans. Often, tests on various chemical products are carried out to prove the safety of the chemical compounds they contain, and the negative results obtained are considered favorable and published. In addition, government-funded research is usually a test of a preconceived hypothesis and it is not necessarily intended to prove or deny that a chemical is safe for humans or the environment.
OBJECTIVE: Chemicals that disrupt the endocrine homeostasis of the human body, otherwise known as endocrine disruptors (EDCs), are found in the blood, urine, amniotic fluid, or adipose tissue. This paper presents the current knowledge about EDCs and the reproductive system.
MATERIALS AND METHODS: The article is an overview of the impact of EDCs and their mechanism of action, with particular emphasis on gonads, based on the information available on medical databases (PubMed, Web of Science, EMBASE and Google Scholar, EMBASE and Web of Science) until May 2021.
RESULTS: EDCs occur in everyday life, e.g., they are components of adhesives, brake fluids, and flame retardants; they are used in the production of polyvinyl chloride (PVC), plastic food boxes, pacifiers, medicines, cosmetics (bisphenol A, phthalates), hydraulic fluids, printing inks (polychlorinated biphenyls – PCBs), receipts (bisphenol A, BSA), and raincoats (phthalates); they are also a component of polyvinyl products (e.g. toys) (phthalates), air fresheners and cleaning agents (phthalates); moreover, they can be found in the smoke from burning wood (dioxins), and in soil or plants (pesticides). EDCs are part of our diet and can be found in vegetables, fruits, green tea, chocolate, and red wine (phytoestrogens). In addition to infertility, they can lead to premature puberty and even cause uterine and ovarian cancer. However, in men, they reduce testosterone levels, reduce the quality of sperm, and cause benign testicular tumors.
CONCLUSIONS: Therefore, this article submits that EDCs negatively affect our health, disrupting the functioning of the endocrine system, and particularly affecting the functioning of the gonads.
Introduction
Endocrine-disruptor chemicals/compounds (EDCs) are chemicals that disrupt the body’s hormonal homeostasis. They play an important role in the functioning of the endocrine system, including the hypothalamic-pituitary-gonadal axis (HPG axis). Some common and widely studied EDCs have a negative effect and a broad spectrum of activity on the endocrine system. These include: (1) plasticizers such as (a) bisphenol A (BPA) is used in the production of polycarbonates and epoxy resins with a very wide range of applications, and b) phthalates used in the production of phthalic varnishes and paints, adhesives, and laminates, and used as plasticizers; (2) polychlorinated biphenyls (PCBs) used as plasticizers, hydraulic fluids and lubricants, in the production of packaging, as a component of printing inks, as an additive to insecticides, adhesives, and plastics, and as an insulation material; (3) polybrominated diethyl ethers; (4) dioxins (a product of the incineration of municipal waste or volcanic eruptions); (5) pesticides (insecticides, herbicides and fungicides) used in the protection of plants, farm animals and food during storage and transport, in the paper and textile industry, in cosmetics; (6) phytoestrogens which are commonly found in our diet, e.g., some vegetables (soybeans, broccoli, onions, tomatoes), fruits, red wine, chocolate, and green tea1,2
The mechanism of action of EDCs is not fully understood. They may impair the functioning of the endocrine system2 . However, it is known that in the case of the female gonad, they may cause changes in the estrogen signaling pathways or interact with estrogen receptors (ER). Similarly, in the case of the male gonad, EDCs may interfere with natural hormones via androgen and its receptor3 . EDCs can act as agonists, mimicking the natural hormone by binding to and activating various hormone receptors (i.e., hydrocarbon receptor [AhR], ER, the pregnane X receptor [PXR, NR1I2], constitutive androstane receptor [CAR, NR1I3]). EDCs can bind to these receptors without activating them (antagonistic activity). Moreover, EDCs, especially in pesticides, can reduce the concentration of hormones by influencing their synthesis, transport, metabolism, and elimination, and interrupt critical cellular processes (Figure 1)4-7.
EDCs can lead to the development of uterine (BPA) and ovarian cancer (BPA), premature puberty (BPA, phthalates), and fertility disorders (BPA). In men, however, they reduce the sperm count (phthalates) and testosterone levels (phthalates) and cause benign testicular tumors (phthalates). Furthermore, EDCs reduce the quality of the sperm, which can result in the development of prostate cancer (BPA). The omnipresence of EDCs, which result in environmental pollution, can lead to many future diseases for which we do not yet have accurate knowledge. It has been demonstrated that some EDCs have thyrogenic, estrogenic, and antiandrogenic properties8. In an era of increasing infertility problems for both men and women, we would like to show any associations between EDCs and fertility. This review analyzes how EDCs influence human health, focusing mainly on the human reproductive system.
Plasticizers: (a) bisphenol A (BPA) and (b) phthalates
(a) Bisphenol A (BPA)
*Mechanistic and Human Studies
(b) Phthalates
*Mechanistic and Human Studies
Polychlorinated Biphenyls
*Human Study
Dioxins
*Mechanistic Studies
*Human Study
Pesticides
*Human Study
Phytoestrogens
*Mechanistic Studies
*Human Study
Limitations
One limitation of our study is that we do not have conclusive data to thoroughly analyze the effects of EDCs on gonads. Secondly, while the mechanism of action and impact of EDCs can be demonstrated in many animal studies, this becomes a significant problem in human reproductive health. Thirdly, longer follow-up is needed to determine how ECDs affect both male and female gonads.
Conclusions
As human beings, we are constantly exposed to many environmental chemical substances, including the many EDCs found in body fluids and tissues. Several studies indicate their additive or synergistic effects. Hence, their action may have unpredictable effects on humans. More and more reliable data indicates that EDCs have side effects on our health, even at low doses. While many epidemiological studies have previously focused mainly on people at risk of persistent exposure to EDCs due to their occupation or those affected by accidental exposure (Soveso, Italy), recent studies have suggested far-reaching effects of EDCs in the general population. The reproductive systems of both women and men are complex and require the proper structure and functioning of many organs, including the pituitary-gonadal axis. EDCs can interfere with reproduction by adversely affecting the organs of the female and male reproductive systems and/or their function.
It should be noted that the chemical industry is interested in results that have a positive effect on the industry itself, indicating that the produced chemical is safe for humans. Often, tests on various chemical products are carried out to prove the safety of the chemical compounds they contain, and the negative results obtained are considered favorable and published. In addition, government-funded research is usually a test of a preconceived hypothesis and it is not necessarily intended to prove or deny that a chemical is safe for humans or the environment.
