Environmental Toxicity - Report Example

Environmental Toxcity Student Name Course Tutor Date Table of Contents Table of Contents 2 Synopsis 3 Introduction 4 Environmental Toxicology 4 Principles of Environmental Toxicology 5 Methods of Testing for Environmental Toxicity 6 Limitations of Environmental Toxicology 8 Current Approaches in Environmental Toxicology 9 Conclusion 10 Works Cited 11 Synopsis Environmental toxicity has been on increase following the release of chemicals forming the pesticides, wastes for the industries and from other human activities. However, some of the wastes are from natural processes such as combustion that releases contaminants into the environment. The study of the toxicity in the environment involves considering the contaminants that are released in the environment, their impacts on the living organisms and what can be done to reduce them. From the principles of environmental toxicity, there are anthropogenic contaminants which are man made and the xenobiotic contaminants that are purely from man’s activities. There are several methods that have been designed for use in testing the environmental toxicity. These methods can be done in the laboratory or in the field. They are in vivo and in vitro but have several limitations that affect their efficiency. For example some agencies are against the in vivo methods since they use the live animals and it is considered not good. However, research is being carried out by scientists to find out other methods that can be efficiently used to test for environmental toxicity to avoid the criticisms that are facing the current methods. Introduction The environment that we live in is filled with toxins from chemicals that have contaminated the air that we breathe, the water that we drink, the foods that people eat and people’s bodies. For the past thirty years, the Environmental Protection Agency has been carrying out National Human Adipose Tissue Survey (NHATS). This is study that involves taking of samples of adipose tissues form cadavers and doing voluntary surgeries in various places and measuring level of toxins in the human bodies. The high toxin load in the environments is due to several years of exposure to chemicals found in contaminated foods, air, and water. Studies have found that both indoor and outdoor airs all contain a certain amount of contaminants. Toxic chemicals are used in all regions of the world and therefore move easily by wind form one region to another. It is therefore difficult to control air contaminants in one region. This can only be done throughout the world to ensure that there is no movement of chemical toxins from one country to another. Environmental Toxicology Environmental toxicology is an interdisciplinary science that employs basic and applied scientific principles to know more about the natural and the anthropogenic contaminants, their life cycles and their effects on the functioning and the structure of the biological and the ecological systems. Environmental Toxicological study can be done both in the laboratory and in the field study work. The study mainly involves assessing how the pollutants that are released into the environment can bring harmful effects and what can be done to reduce their effects to the biological and ecological systems (Zakrzewski, 15). Principles of Environmental Toxicology An environmental contaminant is any substance that is released to the environments from man’s activities, and it appears in amounts that exceeds the natural concentration due to increasing human activities. However, most of the contaminants are anthropogenic, meaning they are man-made. When the contaminants are purely from the man’s activities, they are called xenobiotic. This is explained as a foreign material that is not produced naturally and cannot be considered as an element of any biological system. Some of the environmental contaminants can be from natural sources and processes. For example the polycyclic aromatic hydrocarbons that are produced as a result of incomplete combustion of natural compounds and re found in large amounts in the smoke from burning forests. When their concentration becomes excess in the environment, they are therefore defined as environmental pollutants (Cockerham, & Shane, 154). Emission of metallic compounds in the environment can be as a result of both natural and anthropogenic processes. However, the anthropogenic sources of contaminants may be as many times more than the natural sources. It is therefore very important to determine the sources, amount, and the processes that results to more environmental contaminants in the region and population under study. When an organism, to the ecological system gets exposed to a contaminant in the environments, the impact of the contaminant will be determined by the things that take place as the contaminants travels through the body of the organism or into the ecological system. To understand the potential harm that could be caused by the chemical, it is very important to consider the method if absorption, distribution into the organism body and the means of excretion of the chemical substance. In vitro and in vivo testing of environmental toxicity can be done on the cells and the tissues of the organism that has been exposed to an environment that is contaminated. The cell may get damaged in its membrane by substances that may tamper with its membrane permeability and its integrity. Tissues are covered by the epithelium that protects them from the toxins that may damage it. Exposure to environmental toxins that may affect the tissues may therefore interfere with the epithelia barrier of the tissues (Bassetti, Yu, & Tsunoda, 98). Foreign materials can enter the body from the environment by various means. The first one is through the gastro intestinal tract. This part is significant for exposure to food and water contaminants in the environment. The respiratory tract is also significant in environmental and industrial exposure to environmental air pollutants. The skin is also a route for environmental and industrial exposure (Center for Disease Control and Prevention, 14). Methods of Testing for Environmental Toxicity Environmental toxicology is a business of the producers, users, and chemical regulators to assess the impact of the chemicals that are released into the environment to the biological systems of those affected. To determine whether exposure to a particular substance can cause adverse effects, the study can be done in three ways that include observing people who are under normal or accidental use of the suspected substance, carrying out experiments using animals and by studying the cells of humans, animals, or plants (Yu, 143). Epidemiology studies have been have been done on human beings to find out whether there is a relationship between exposure to some environmental substances and adverse effects on health of the exposed individuals. Epidemiological studies are done on humans to determine the risk of illness or in some cases death to the population that has been exposed as compared to similar others who have not been exposed to the suspected substances. Epidemiological studies are divided into cohort studies where a group of humans or animals are exposed to the chemical contaminants and others are not. The two sets are then observed for e period of time to check on the occurrence of diseases resulting from the exposure. The other one is the case control studies where a group of people suffering from a disease that is associated with environmental toxin exposure such as cancer and others who do not suffer from such a disease to determine whether there is an association between the disease and prior exposure. Cross –sectional study is also done where a group of people are exposed to some agents for example in determining the occurrence of respiratory infections among the furniture maker, or those people dealing with pesticide manufacture (Nandis, Mickiewicz, & Matthews, 75). The group is then followed to check whether exposure to the furniture making environment can cause the respiratory infections. The other one is ecological studies where disease prevalence in one area where there is exposure of a certain agent is assessed. For example cancer prevalence may be assessed in areas where there is high concentration of toxic wastes as compared to other areas where there is zero or minimal exposure. Other methods of testing for environmental toxicity are in vivo and in vitro involving life animals and tissues and cells respectively. Most toxicologists however argue that in vitro methods are cost effective, they do not consume a lot of time and give reliable results. Limitations of Environmental Toxicology Both in vivo and in vitro methods are used in testing for the effects of environmental toxics to the biological and ecological system. These methods however have their limitations that affect the results of the studies that are carried out. In vitro means tests that are done in a glass in the laboratory. These do not involve the living animals or humans but are done on tissues and cells of either humans or animals. The in vitro methods of toxicology are done to determine the presence of potentially toxic agents and to confirm the absence of the same agents in development processes of some therapeutic stuff such as drugs, farm chemicals, and foods additives that may have good or bad tastes. However, the in vivo methods have some limitations that affect their use. Some government agencies control the use of in vivo methods of toxicology due to some societal associations that campaign against use of live organisms in doing laboratory tests. These agencies therefore promote the use of in vitro toxicology methods that makes use of human cells and tissues from the affected areas of the body to determine the effects of environmental toxins in the human and animal bodies. The campaign against the in vivo method is therefore a major limitation since in some occasions, the two methods could give varying results and the one involving live organisms gives the most reliable results (Mothersill, 120). Current Approaches in Environmental Toxicology Following the criticism of the in vivo toxicology methods, other approaches to environmental toxicology have been developed. These include the use of the robot system that is used together with the more advancing in vitro and computational approaches. These methods have been revealed effectiveness in indicating the processes that chemicals released into the environment interact with the biological systems. Scientists also say that these methods indicate results that can be closely related to humans more than those that were done on live animals. However, in vitro approaches are viewed as the most reliable in testing large accumulation of industrial wastes. The director of National Toxicology Program in the United States says that they are now more comfortable with the current change from using animals in toxicology tests to using the bio-chemical methods in making decisions on health policies. However, the current methods of assessing toxicity in the environment have some draw backs that hinder their reliability on the natural environment. This is because most of the methods can only assess one substance at a time. The tests that are carried out in these current methods however indicate well the safety margins that should be considered for uncertainties, for example how the environment or humans may get affected by exposure to various levels of chemicals. However, this has raised some concerns that it does not offer enough security and that the combined effects of the chemicals should be assessed in a more specific manner. Another concern is due to the fact that animal tests are done on toxic levels that are in most cases higher than their content in the environment. This means that the test results will not be very relevant when interpreted on humans. The other drawback to the modified in vitro tests is that it is hard to achieve compound integrity. This is because most laboratories keep their chemicals in dimethyl sulfoxide which is a polar solvent and can mix with both polar and non polar mixtures. It can also absorb the atmospheric moisture and degrade the substances that are stored in it. This can precipitate the stored compounds and will therefore interfere with the tests to be done. Further research is going regarding new and improved methods of testing for environmental toxicity. Scientists are working to identify as many pathways for toxic chemicals into the environment as possible. They believe that each chemical substance has a pathway for entry in to the natural environment and that identification of theses can help in identifying the impact of the contaminants and its target organisms. However, other scientists are arguing that multiple groups of chemicals may be sharing a similar pathway regardless of the chemicals’ structural differences. Research is therefore going on to identify means of distinguishing this and to evaluate on their toxic effects (Rose, 64). Conclusion Environmental toxicity has been on increase and its threatening the lives of many living organisms on the ecosystem. The issue is increasing to become a problem due to the high rate of industrialization that is leading to the release of many toxins in to the environment. The toxins in the air have been found to travel by wind and can move from one country to another. It is therefore important for governments in all affected nations to set policies that will guide the release of industrial pollutants in all areas. To clear the current existing pollutants in the environment, methods of testing for the environmental toxicity should be properly developed since this will be the only way to identify the routes of contaminants and their impacts on the biological systems of the ecological members. With the continued increase of the substance release, research should also continue to identify better means of environmental toxicology and means of reducing the level of contaminants in the natural environment (Wright, 113). Works Cited Zakrzewski, Sigmund. Environmental toxicology. Oxford, Oxford University Press, 2002. Cockerham, Lorris. & Shane, Barbara. Basic environmental toxicology. Routledge: Boston, 1999. Bassetti, W., Yu, Ming-Ho & Tsunoda, Humio. Environmental Toxicology: Biological and Health Effects of Pollutants, Second Edition. New York: CRC Press, 2004. Yu, Ming-Ho. Environmental toxicology: impacts of environmental toxicants on living systems, New York: CRC Press, 2001. Mothersill, Carmel, & Austin, Brian. In vitro methods in aquatic toxicology. New York: Springer, 2003. Rose, John. Environmental toxicology: current developments. London: SAGE, 1998. Center for Disease Control and Prevention. Second National Report on Human Exposure to Environmental Chemical, retrieved on may, 26th 2010 from Wright, David. Environmental toxicology. Cambridge: Cambridge University Press, 2002. Nandis, Wayne. Mickiewicz, John. & Matthews, G., 1996, The layered and Historical nature of ecological systems and risk assessment of pesticides. Environmental Toxicology and Chemistry, Vol.15, pp. 432-440 Read More

Environmental Toxicology Environmental toxicology is an interdisciplinary science that employs basic and applied scientific principles to know more about the natural and the anthropogenic contaminants, their life cycles and their effects on the functioning and the structure of the biological and the ecological systems. Environmental Toxicological study can be done both in the laboratory and in the field study work. The study mainly involves assessing how the pollutants that are released into the environment can bring harmful effects and what can be done to reduce their effects to the biological and ecological systems (Zakrzewski, 15).

Principles of Environmental Toxicology An environmental contaminant is any substance that is released to the environments from man’s activities, and it appears in amounts that exceeds the natural concentration due to increasing human activities. However, most of the contaminants are anthropogenic, meaning they are man-made. When the contaminants are purely from the man’s activities, they are called xenobiotic. This is explained as a foreign material that is not produced naturally and cannot be considered as an element of any biological system.

Some of the environmental contaminants can be from natural sources and processes. For example the polycyclic aromatic hydrocarbons that are produced as a result of incomplete combustion of natural compounds and re found in large amounts in the smoke from burning forests. When their concentration becomes excess in the environment, they are therefore defined as environmental pollutants (Cockerham, & Shane, 154). Emission of metallic compounds in the environment can be as a result of both natural and anthropogenic processes.

However, the anthropogenic sources of contaminants may be as many times more than the natural sources. It is therefore very important to determine the sources, amount, and the processes that results to more environmental contaminants in the region and population under study. When an organism, to the ecological system gets exposed to a contaminant in the environments, the impact of the contaminant will be determined by the things that take place as the contaminants travels through the body of the organism or into the ecological system.

To understand the potential harm that could be caused by the chemical, it is very important to consider the method if absorption, distribution into the organism body and the means of excretion of the chemical substance. In vitro and in vivo testing of environmental toxicity can be done on the cells and the tissues of the organism that has been exposed to an environment that is contaminated. The cell may get damaged in its membrane by substances that may tamper with its membrane permeability and its integrity.

Tissues are covered by the epithelium that protects them from the toxins that may damage it. Exposure to environmental toxins that may affect the tissues may therefore interfere with the epithelia barrier of the tissues (Bassetti, Yu, & Tsunoda, 98). Foreign materials can enter the body from the environment by various means. The first one is through the gastro intestinal tract. This part is significant for exposure to food and water contaminants in the environment. The respiratory tract is also significant in environmental and industrial exposure to environmental air pollutants.

The skin is also a route for environmental and industrial exposure (Center for Disease Control and Prevention, 14). Methods of Testing for Environmental Toxicity Environmental toxicology is a business of the producers, users, and chemical regulators to assess the impact of the chemicals that are released into the environment to the biological systems of those affected. To determine whether exposure to a particular substance can cause adverse effects, the study can be done in three ways that include observing people who are under normal or accidental use of the suspected substance, carrying out experiments using animals and by studying the cells of humans, animals, or plants (Yu, 143).

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