Endocrine Disruptors
During recent years, numerous newspaper and magazine articles have suggested that humans may be at risk because small amounts of well known environmental contaminants, such as dioxin, PCBs and DDT, can affect hormone levels. Hormones are produced by the endocrine system as regulators of biological function in target organs. Because hormones play a critical role in early development, toxicological effects on the endocrine system often have an impact on the reproductive system. The term endocrine disruptor is used to describe chemicals that can mimic hormones and may either enhance or counteract their effects. It has been suggested that these hormone changes can, in turn, lead to a variety of health problems including cancer, decreased fertility, and abnormalities in newborns.
Evidence provided to support these claims of human and wildlife harm is largely from laboratory studies in which large doses are fed to test animals, usually rats or mice, and field studies of wildlife species that have been exposed to the chemicals mentioned above. In laboratory studies, high doses are required to give weak hormone activity. These doses are not likely to be encountered in the environment. However the process of bioaccumulation can result in top-level predators such as humans to have contaminants at levels many million times greater than the environmental background levels (Guilette 1994). In field studies, toxicity caused by endocrine disruption has been associated with the presence of certain pollutants. Findings from such studies include: reproductive disruption in starfish due to PCBs, bird eggshell thinning due to DDT, reproductive failure in mink, small penises in alligators due to DDT and dicofol (Guillette 1994, Colburn et al 1996). In addition, a variety of reproductive problems in many other species are claimed to be associated with environmental contamination although the specific causative agents have not been determined. One recent discovery that complicates the situation is that there are many naturally occurring "phytoestrogens", or chemicals of plant origin that exhibit weak estrogenic properties.
Pesticides that behave like the female hormone estrogens can have serious effects on reproductive success and function on animal exposed to them. Reproductive success or fitness is defined by having live reproductively capable off...
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The rhetorical occasion of this excerpt is to inform others about the dangers of chemicals on earth’s vegetation and animal life.
The pesticide DDT banned in 1987 was a detrimental to the environment leading to it to be banned in 1987. DDT remains in the soils for a long period of time. The chemicals affect the ecology of the soil and water run off causing contamination of livestock and native animals and aquatic species. Studies indicated a range of human health impacts from DDT including cancers, infertility, miscarriage and nervous system impairment. The social and economic impact of DDT use in viticulture was significant.
“High levels of hormones can cause problems in the human body, but can hormones we ingest really alter our hormone level...
The premise of Theo Colborns’ research was to find the connection between the rising incidences of cancer and environmental contamination in the Great Lakes region. However, during field and laboratory studies, Colborn discovered that there was no direct link between the contamination and cancer. However, Colborn did find reoccurring patterns of abnormal behavior and deformed offspring amongst the wildlife populations in the Great Lakes region. Elevated levels of polychlorinated biphenls (PCBs), pesticides dieldrin, DDT, lindane and chlordane were found during tissue analysis of the wildlife in the Great Lakes region (Colborn et. Al 1996). These elevated levels were found in offspring of the wildlife who appeared to be healthy. This supported Colborns’ hypothesis that these contaminations disrupt hormones produced by the endocrine system during growth and development, which will then cause physical and behavioral abnormalities in the fetus.
When these “messages in bottles'; reach their appointed destination, the binding into the receptor site causes a cascade of reactions to occur. It is these reactions that are vital in maintaining our homeostasis. Many times the binding of the receptor site causes a direct expression of a certain gene. This is where endocrine disrupters can exert major damage. In addition to gene expression, endocrine disrupters cause havoc in many other areas of the body. What exactly are endocrine disrupting chemicals?
Hayes et al. 2002. Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses. Proc Natl Acad Sci USA 99: 5476–5480.
The manner in which a teratogen impacts the developing human may vary, though nicotine, caffine and medication consumption are all directly related to physical development. These are examples of habitual teratogens, each contributing to low birth weight and behavioral problems in adolescents. The level of influence of any given teratogen depends on many factors; the first, called the “threshold effect,” occurs when a relatively harmless teratogen in small quantity becomes toxic at a spe...
PPCPs that have been found in tap water and source water include an array of chemicals such as sulfamethoxazole: an antibiotic, estrone: an estrogen containing chemical, atrazine: a herbicide, naproxen: an anti-inflammatory drug and meprobamate: an anxiety medicine. (Alliance for the Great Lakes). The effect of these pharmaceuticals on the wildlife is no fairytale matter. The 2002 USGS report stated that endocrine disrupting chemicals (chemicals that alter the hormone balance in an organism) such as estrogene which is found in estrone were linked to the occurrence of intersexed, cancerous and reduced size organ...
In 2013, nearly 1.7 million immigrants entered the United States -- a nation built with the blood and sweat of the millions of immigrants who came to it -- in search of a better life, one free from tyranny and oppression. However, only nine hundred thousand of these immigrants entered the country legally, vesting their time and resources into the legal residency “green card” program -- the very first step to full citizenship (Monger). The other seven hundred thousand immigrants entered the country illegally, exploiting security failures on the US southern border, and policy failures in Washington, DC (Morgan). While a large proportion of the undocumented population poses no immediate threat
Although the number of women dying from ovarian cancer in the United States has continued to rise, the risk of ovarian cancer can be reduced by the use of oral contraception. Throughout researching for this topic, one woman may have brought precaution to their reproductive system. Overall, certain occupational exposures may be associated with ovarian cancer. This life-style may be simultaneously gotten or genetic susceptibility. Although the collective evidence of an association between ovarian cancer and environmental agents is limited, occupational exposures should be considered in future studies of ovarian cancer.
"Pesticides." Issues & Controversies On File: n. pag. Issues & Controversies. Facts On File News Services, 18 July 2005. Web. 20 May 2011. .
The advancement in chemical technology with these improved pesticides has created improvements in the public health as well. From this, perhaps, we have become careless in our use and control of them. While there are many positive points, there are also extreme risks involved in using th...
In a widely reported study of smallmouth bass from the Potomac River, male fish were found to have female ovarian tissue within their testes. In another study, fish exposed to wastewater from a metropolitan area sewage treatment plant exhibited endocrine disruption, i.e. male fish produced female egg-yolk proteins (Pharmaceuticals and Personal Care Products). To date, no studies directly link trace chemicals found in water with human health problems but there are countless reasons for concern. Could exposure to these minute amounts of drugs in our water cause drug resistance? Could one unknowingly ingest a drug to which they are allergic to simply by drinking water? And how do these trace amounts of drugs, which may not be harmful to humans, affect a
Saudi Arabia, the leader of OPEC (Organization of Petroleum Exporting Companies), maintains a powerful position in negotiations with the U.S. and other countries. Its vast supply of oil directly effects per barrel pricing and is a unique bargaining tool in international politics. But Saudi Arabia is no ordinary country in today's world. Its borders are governed by a royal family of nearly 30,000 individuals, all of which share most of the wealth and almost all of the power. Its people, with foreign exceptions, are wholly Islamic and many practice the faith with a frightening sense of devotion. And despite the immense revenue generated by its oil reserves, part of its population still lives in absolute poverty. Although recently it has seen immense change, it is still a country fair behind the progressive world.
Fear, worry, and anguish were major themes of World War Two. During those years, 1939 to 1945, Totalitarianism was running amuck and many people wondered when, if not, if these years would ever end. In the book 1984 by George Orwell takes the aftermath of WW2, times in which he lived through, in the year 1949 and essentially gathers those feelings and aspects of society, for example nationalism, and puts them in a novel form . The book takes place in a future dystopia located around England, called Oceania. In this novel, the author writes about a character named Winston Smith who is a middle class citizen whose actions, like all others, are monitored by the government. Winston, society, the government, and many other parts of life written