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Toxic: a chemical that has a median lethal concentration (LC 50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats ...
Environmental hazards can be categorized in many different ways. One of them is — chemical, physical, biological, and psychological. Chemical hazards are substances that can cause harm or damage to humans, animals, or the environment. They can be in the form of solids, liquids, gases, mists, dusts, fumes, and vapors.
Overview of the interdisciplinarity of environmental toxicology Categories of organisms commonly used for assessing environmental toxicity. Environmental toxicology is a multidisciplinary field of science concerned with the study of the harmful effects of various chemical, biological and physical agents on living organisms.
The usual cause of death is dehydration. Most cases of diarrheal illness and death occur in developing countries because of unsafe water, poor sanitation, and insufficient hygiene. Other waterborne diseases do not cause diarrhea; instead these diseases can cause malnutrition, skin infections, and organ damage. [3]
Air pollution can cause diseases, allergies, and even death to humans; it can also cause harm to other living organisms such as animals and crops, and may damage the natural environment (for example, climate change, ozone depletion or habitat degradation) or built environment (for example, acid rain). [2]
Third, according to the second law of thermodynamics, order can be increased within a system (such as the human economy) only by increasing disorder or entropy outside the system (i.e., the environment). Thus, technologies can create "order" in the human economy (i.e., order as manifested in buildings, factories, transportation networks ...
Methylmercury is extremely toxic, and its derivatives are the major source of organic mercury for humans. It is a bioaccumulative environmental toxicant with a 50-day half-life . [ 1 ] [ clarification needed ] Methylmercury (derived biologically from dimethylmercury ) is the causative agent of the infamous Minamata disease .
Since 1997, United States law has declared a list of bio-agents designated by the U.S. Department of Health and Human Services or the U.S. Department of Agriculture that have the "potential to pose a severe threat to public health and safety" to be officially defined as "select agents" and possession or transportation of them are tightly controlled as such. [5]