MHE513 - Risk Assessment and Epidemiology Module 5 - Case - Essay Example

The metals such as zinc, manganese, iron, fluoride are considered as toxic non-carcinogens. Whereas chromium, ethylene bromide are considered as toxic carcinogens. The major difference between these two is that the toxic carcinogens will affect and alter the cells from its genetic level. Whereas the toxic non carcinogens will affect only the structure of the cells. The carcinogenic chemicals have the capability to induce the mutagenic activity in the cells. These chemical reach the human body through inhalation and by dermal contact.

The chemicals that gives rise to toxic endpoints other than cancer and gene mutations are called as ‘systematic toxicants’ because these toxins will affect only the organs of the system at a lethal dose or due to continuous exposure to these chemicals. (Asante-Duah, 2002). For many toxic non carcinogens there are many protective mechanisms and treatment methods to overcome the toxicity, before it becomes severe. Whereas, the exposure to the carcinogens will create toxicity which is usually not recoverable.

Even the small exposure to carcinogens has severe effects. The toxicity parameters of non-carcinogenic chemicals are based on the “acceptable daily intake” (ADI). ADI is the amount of chemical (in mg/ kg body weight/day) to which a receptor can be exposed to on a daily basis over an extended period of time. (Asante-Duah, 2002). The toxicity parameters of the carcinogenic chemicals are based on the sensitivity of the sub population. The carcinogenic effect can be seen at the first exposure or even after many years of continuous exposure.

Moreover the uncertainty factors are heavy for carcinogens than for non-carcinogens. Hence the communication of the risk to the people differs for the two types. Though for both the carcinogenic and non-carcinogenic chemicals the handling, the exposure levels, the