Environmental Toxicology and Human Health

Environmental Toxicology and Human Health

Environmental Toxicology is a field of science with various disciplines involved in the study of the adverse effects of various physical, chemical and biological agents on living organisms particularly animals, birds and fishes (Philp, 2001, pp. 10-11).

Physical agents.

They are sources of energy that may have negative effects on human health and that of biological organisms such as fish, birds and animals (Philp, 2001, pp. 20-25). One such agent is noise which can be defined as unwanted sound. Noise has both permanent and temporary damage to the ears rendering one incapable of hearing or resulting to tinnitus both of which are irreparable (McCally, 2002, pp. 58-67). Noise in the workplace also poses a threat to the workers in that they may fail to hear sounds indicating threats. Vibration, also a physical agent is categorized into two: hand-arm vibration (HAV) and whole body vibration (WBV). Continuous exposure to HAV has been proven to lead to hand-arm vibration syndrome a permanent and incapacitating health effect such as musculoskeletal disorders of the hand (McCally, 2002). On the other hand, continued exposure to WBV is associated with severe pain on the lower posterior. Optical radiation also has some grim effects on the health of people. Ultraviolet radiation emanated by the sun presents the utmost danger to our health. When exposed to the eyes it may lead to spoiled cornea and severe pain while exposure on the skin may vary from burning, redness and hastened ageing through skin cancer of different types. Electromagnetic fields (EMFs) generated due to electrical energy used may also be detrimental (Philp, 2001). Though they seldom occur, constant exposure to the EMFs can result to severe effects depending on the frequency of the radiation. Electricity can also be viewed as a threat since it may lead to death or severe injuries such as electric burns, thermal burns and electric burns to people. Last but not least we have ionizing radiation. Contact with low-level ionizing radiations may lead to cancer and DNA mutations while high-level exposures cause radiation sicknesses and burns (Philp, 2001).

Biological agents.

These include bacteria, viruses, fungi, other microorganisms and toxins associated with them. While some of these agents have no harmful implication on the human health, others have the potential to affect the human health in various ways ranging from moderately mild, allergic reactions to serious medical illnesses even demise. These agents occur widely in the environment (Environmental Toxicology And Human Health, n.d.). Biological agents have the capacity to reproduce rapidly, require little resources to live and can poison at very small doses thus they are a probable danger in a widely in our environment. Biological agents can be categorized into four sets according to their severity of infection and likelihood of prevention and treatment (McCally, 2002, pp. 150-200). Group 1 agents are those with low chances of causing ill effects to the organisms. Group two consists those toxicities that are unsafe for the workers but chances of spreading to the community are very minimal. Group 3 agents are those that can cause severe human disease, pose a serious threat to the workers and are likely to spread to the community. However, these toxicities can be treated. Group 4 agents are similar to group 3 agents except for the fact that there is no effective management for them. These are some of the most contagious and extensive biological agents: anthrax, botulism, avian flu, and Ebola (Environmental Toxicology And Human Health, n.d.).

Chemical agents.

These are as a result of the products we use in our day to day doings. Pesticides are a perfect instance of chemical toxins (Lakind). Pesticides persist in the environment long after their use which can result in bioaccumulation of chemicals in various organisms along with biomagnification within a group of organisms that depend on each other for food. (DDT) is another agent that was banned due to its negative effects on living organisms (Lakind). The reactions chemical toxicities is dependent on several factors that I will briefly discuss. Age is a significant aspect in establishing the response to a toxic chemical (Lakind). For example, parathion is more lethal to young animals. Although very rare, sex can determine the response to a toxicant. For instance, when exposed to parathion the female rat is twice as affected as the male rat. The responses to a toxic chemical also depends on the species (Safe). For example, insecticides are lethal to insects but relatively non-toxic to animals. Toxicity of a chemical is determined by factors such as: the dosage-it is the most critical factor if a substance will be acute or a chronic toxicant (Lakind). The form that a chemical agent is in also defines its toxicity. For instance, the poisonousness of mercury in gas form is very different from methyl mercury. The entry point of a toxin is also a measure of its toxicity. One other factor is the rate of removal from an organism’s system. According to Paracelsus all substances are poisons only the dose differentiates whether it is a poison or a remedy (Safe).

Exposure assessment is the process of establishing the regularity, period and expansiveness of exposure to toxicities together with the traits and number of the population exposed. Methods of exposure assessment include direct and indirect approach (Philp, 2001, pp. 100-108). In direct approach exposure to the agents is determined by monitoring the pollutant concentrations reaching the person while in indirect approach the toxicant concentration is measured during specific human activities to predict the exposure distributions within a population (McCally, 2002). Epidemiology is important to research studies of environmental health since many environmental exposures can be addressed only by comparing populations instead of individuals and the interruption of both local and universal environments require us to come up with new methods of study design that is epidemiology. The epidemiologic approach to studying environmental health problems has its limitations. One of such constraint is the quick changes in the health and nutritional status of many populations that have been affected majorly which may lead to inconclusive results (Safe). Another limitation is the fact that data collected through epidemiology is often ignored and limited by factors such as limited resources, personal priorities, political concerns and public relations (Philp, 2001). Since epidemiology depends on valid data, restriction on the gathering of data can be considered a constraint. This may be due to insecurity or lack of resources preventing the researchers from submitting surveillance data (Safe).

References.

Environmental Toxicology And Human Health. (n.d.). Retrieved from

Lakind, J. S. (n.d.). Workshop on Human Milk Surveillance and Research on Environmental Chemicals in the United States. journal of Toxicology and Environmental Health, Part A.

McCally, M. (2002). Life support the environment and human health. MIT Press.

Philp, R. B. (2001). Ecosystems and human health: toxicology and environmental hazards. Lewis Publishers.

Safe, S. (n.d.). Toxicology, Structure-Function Relationship, and Human and Environmental Health Impacts of Polychlorinated Biphenyls: Progress and Problems. Environmental Health Perspectives.