Endocrine Disruptors: Phthalates
Endocrine disruptors are chemicals in our environment when they get into the human body affects the endocrine system significantly. The endocrine system is essential in the human as it is made up of gland secreting hormones essential for various biological processes in the body(Hauser). There are various types of endocrine disruptors, including Dioxins, Perchlorate, Phthalates, Phytoestrogens, Bisphenol A (BPA), Polybrominated diphenyl ethers (PBDE) among others. This paper is a discussion on Phthalates as an endocrine disruptor.
Di-2- Ethylhexyl phthalate (Phthalates) is a human-made synthetic chemical and an endocrine disruptor if ingested in the body. Its mainly used to make plastic more flexible. Its added to Polyvinyl chloride plastics (PVC) to make various items such as vinyl floors, food wraps, and packaging sheets and is also applied in vinyl gloves used in hospitals. Annually approximately 18 billion pounds of the chemical is used as plasticizers (Hauser). They do not form strong molecular bonds with PVC; hence are quickly released to the environment. The exposure to the human population is high due to the extensive usage of the chemical. The exposure is through ingestion in food and beverages, inhalation, or skin contact from handling many plastics.
Literature studies on the effect of phthalate on the human body indicate it’s a reproductive toxicant (Yang et al.). Phthalate targets the testis in males, especially the Sertoli cells, and in females, the granulosa cells in the ovaries. The reproductive system in males and females is controlled and regulated by hormones from the hypothalamus and anterior pituitary gland, which interact with those secreted from the reproductive tissues and organs. The pathway starts at the hypothalamus, which receives the signals a hormone is needed. Then, it stimulates the anterior pituitary gland by sending a gonadotropin-releasing hormone. There is a release of two hormones in the anterior pituitary, which involve the luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH in males stimulate Sertoli cells to begin the spermatogenesis process, which produces sperm through a negative feedback mechanism. Also, stimulate the Leydig cells to secrete testosterone, a hormone essential for developmental functions in males, and physiological process (O’Donnell et al.). In females, they stimulate the follicles in ovaries to secrete estrogen and progesterone essential hormones in menstrual and development of secondary characteristics (Rojas et al.). Phthalates in males inhibit the FSH in the stimulation of the Sertoli cells, and females inhibit the oestradiol secretion from the granulosa cells in the ovaries.
The adverse effects associated with phthalates begins in vitro. The exposure to this chemical occurs at intrauterine hence some anomalies arise during the development of the reproductive system (Yang et al.). The male reproductive tract is dependent on the fetal testosterone, which phthalate affects the action and production, leading to abnormal development of the testis in fetal and neonatal life. Conditions such as cryptorchidism and hypospadias have been linked to phthalates. In contrast, females their development of the reproductive tract is independent of hormones; however, disruption of the normal processes can occur, leading to the secretion of androgens, which causes the masculinization of the female fetus. In puberty, the effects involve delays in the development of secondary characteristics. Studies indicate there is premature development of breasts in females. In males affects the sperm quality leading to infertility. Long term adverse effects are endometriosis occurrence and premature loss of pregnancies in females. Also, predisposes to testicular cancer for males and causes respiratory airway obstruction and asthma in inhalational exposure (Hauser).
Currently, there exist no policies against the phthalates use in plastics manufacturing; however, some nations have created some regulation in its use and disposal. The European Union restricts the utilization of phthalates in making children products such as toys or in their articles since 1999. In 2008 the United States passed an act to control the usage of the chemical in making children products (Yang et al.). In conclusion, phthalates are a health hazard, and there exists a literature gap in the effects in humans, especially children who are exposed to more due to consumption on soil material at any time. Many studies existing has been done on animals.
Works Cited
Hauser, R. “PHTHALATES AND HUMAN HEALTH.” Occupational and Environmental Medicine, vol. 62, no. 11, Nov. 2005, pp. 806–18, doi:10.1136/oem.2004.017590.
O’Donnell, Liza, et al. “Endocrinology of the Male Reproductive System and Spermatogenesis.” Nih.Gov, MDText.com, Inc., 11 Jan. 2017, www.ncbi.nlm.nih.gov/books/NBK279031/.
Rojas, Joselyn, et al. “Physiologic Course of Female Reproductive Function: A Molecular Look into the Prologue of Life.” Journal of Pregnancy, vol. 2015, 2015, pp. 1–21, doi:10.1155/2015/715735.
Yang, Oneyeol, et al. “Endocrine-Disrupting Chemicals: Review of Toxicological Mechanisms Using Molecular Pathway Analysis.” Journal of Cancer Prevention, vol. 20, no. 1, Mar. 2015, pp. 12–24, doi:10.15430/JCP.2015.20.1.12.