Ld50 Correlative Model

What has been brought to light in recent years is the effects of these chemicals on the body’s immune response. By introducing these toxic chemicals into the body, the potency of the immune system is compromised. More commonly than not, the body’s magnificent defense system will kick in and destroy foreign invaders but all it can take is an overwhelming amount of chemicals to slow or even shut down the body’s response systems. A large amount of these types of chemicals introduced into the body at one time would be considered acute toxicity and could even cause death. Additionally, a small amount of these poisonous substances brought into the body over a long period would be considered chronic toxicity and can have detrimental effects on the body’s natural response (Hoernschemeyer 55-57). This information is startling enough to want to make a change from conventionally grown food to pesticide-free organic

Also depicted in this paper is the type of cancers caused by each chemical and other related health problems associated with each chemical. Finally, the role of government agencies such as FDA, EPA and OSHA in preventing excessive amount or zero amounts of toxic chemicals from entering the environment will be discussed. The last paragraphs will enumerate the inferred conclusion from my research on Agent Orange, DDT and Benzene.

Also depicted in this paper is the type of cancers caused by each chemical and other related health problems associated with each chemical. Finally, the role of government agencies such as FDA, EPA and OSHA in preventing excessive amount or zero amounts of toxic chemicals from entering the environment will be discussed. The last paragraphs will enumerate the inferred conclusion from my research on Agent Orange, DDT and Benzene.

While there are studies that indicate that DDT can cause health problems such as reduced male fertility, genital birth defects, breast cancer, diabetes, and endocrine disorders (World Wildlife Fund, 1999), many of these studies are weakened by factors such as their age or their biases, due to funding from pro-ban organizations such as the Environmental Protection Agency or the World Wildlife Fund, combined with the lack of conclusive support from more neutral research. Furthermore, one particular paper mentions that methodological errors undermine many studies on the health impacts of DDT (Beard, 2006), and asserts that “it is still too early” to assess DDT’s role in a number of diseases. Chris Curtis, a professor at the London School of Hygiene and Tropical Medicine, also stated that there is “no convincing evidence that DDT … has caused any harm to humans” (Cone, 2009).

Jones, P. R., Sheppard, M. A., & Snowden, C. B. (2010). Impact of poison prevention

The purpose of this course is to provide the fundamental knowledge of the effects of environmental chemicals on living systems, and the toxic responses of the human and plant systems. Students will discuss risk, ethics, and social responsibility with regard to environmental toxicology.

Between 2002 and 2005 alone, the amount of chemical substances produced or imported in the United States increased from 42 billion pounds per day to 74 billion pounds per day. The amount of chemicals in commerce in the United States has increased from 62,000 grandfathered chemicals in 1976, to almost 83,000 in 2008, a difference of more than 20,000. Of this 83,000, the EPA has only been able to ban or restrict five chemicals under TSCA: PCBs, dioxin, CFCs, hexavalent chromium, and asbestos. Additionally, the EPA has independently tested only 250 of the 83,000 registered chemicals in commerce in the United States. Richard Denison, a Senior Scientist for the Environmental Defense Fund explained these incredibly low numbers by stating, “TSCA places an impossibly high burden on EPA before it can act to control a chemical.” In fact, under TSCA, “the EPA can’t even require testing to determine whether a risk exists without first showing a risk is likely.” For that reason, a large majority of chemicals used in the United States have never been tested for health and environmental effects. Studies have shown that due to the proliferation of these chemicals into homes, workplaces, and schools, the average American has a detectable concentration of 300 environmental chemicals. Among other issues, many of these chemicals can affect brain and organ function and cause cancer. Consequently, it is clear that

The history of life on this earth has been a chain of interaction between living things and their surroundings. Change can be good but in this case change is bad. We as humans have been destroying our planet by air, earth, rivers, and sea with the most dangerous materials. Polluting our most precious and limited resources we have been our greatest enemy. We have created these irrecoverable effects that now everyone living on the planet is being affected but also the tissues of the living of everything is now being changed. Chemicals are sinister and a partner to radiation and here is some background information as stated in “The Obligation to Endure” by Rachel Carson pg. 466 where it lists a chain reaction of the chemical to our environment

TCDD is a dioxin that can be produced through diesel exhaust, burning waste, and chemical manufacturing. In recent years, many have argued that exposure to this chemical can cause serious illnesses. Studies on animals have shown that TCDD is one of the most poisonous chemicals out there. The animal testing has been found to be especially toxic to developing babies in the womb. A pregnant rat given a dose of less than one part per billion (which is comparable to a single drop in 14,000 gallons of water) will cause female sexual characteristics in a male embryo. Doses of 100 parts per billion in rodents and fish have been proven to cause birth defects such as cleft palates, malfunctioning kidneys, heart problems, and weak bones (Schmidt). Animal studies have proven that small doses of TCDD can be severely detrimental to one’s

These substances not only trigger liver, heart, kidney and nervous system deterioration, but also cause lung impairment and cancer.

Since this is my fist toxicology course, I found it interesting to learn the variety of pathways that toxicants access to enter the human body and aquatic organisms. Even more so, the way our cells respond to the intake of such toxicants. In addition, learning the way aquatic organisms are impacted by toxicants in stream and stream sediments. Furthermore, I can use this knowledge in a career and also for my own curiosity to investigate my surroundings or spread awareness.

The objective of the subacute toxicity test is to determine toxicity after repeated administration of the tested material. It helps to establish doses for sub-chronic studies. The duration of Sub- Acute Toxicity test is 14 to 90 days. The test system uses 2 species that may contain mice, rats, rabbits, guinea pigs, dogs. The dose administration contains 3-4 doses given by the same routes as the previous toxicity. The routes commonly used are Oral, dermal or intravenous. The parameter considered are mortality, weight change, signs of toxicity, clinical pathology, pathology and histology. The sub- acute toxicity test uses laboratory strains of young healthy adult rats. The study is performed at 4 different dose levels. The test compounds are administrated on route

The molecular structure of a substance can help to predict the toxicity of it. By comparing the substance 's structure to that of more than 12,000

David Salsburg of Pfizer Central Research has noted that of 19 chemicals known to cause cancer in humans when ingested, only seven caused cancer in mice and rats using the standards set by the National Cancer Institute. This justifies that many substances that appeared safe in animal studies and received approval from the U.S. Food and Drug Administration for use in humans later proved dangerous to people. The drug milrinone, which raises cardiac output, increased survival of rats with artificially induced heart failure; humans with severe chronic heart failure taking this drug had a 30 percent increase in fatalities. Also, the antiviral drug fialuridine seemed safe in animal trials yet caused liver failure in seven of 15 humans taking the drug (five of these patients died as a result of the medication, and the other two received liver transplants). Scientists and the populous that do not agree with

Marcus, S. (2012). Poison prevention: engineering in primary prevention. Clinical Toxicology (Philadelphia, Pa.), 50(3), 163-165. doi:10.3109/15563650.2012.658474