LINK / CITE ADD TO WORD LIST. adjective. The definition of harmful is something that causes damage or is able to be hurtful. A chemical that causes you to become sick is an example of a chemical that would be described as harmful. causing or able to cause harm; hurtful. adjective.
The most common way to become infected with giardia is after swallowing contaminated water. Giardia parasites are found in lakes, ponds, rivers and streams worldwide, as well as in municipal water supplies, wells, cisterns, swimming pools, water parks and spas. Ground and surface water can become contaminated from agricultural runoff, wastewater discharge or animal feces.
Currently, five to six morphologically distinct species are recognised. Giardia lamblia (= G. intestinalis, = G. duodenalis) infect humans and other mammals, G. muris is found from other mammals, G. ardeae and G. psittaci from birds, G. agilis from amphibians and G. microti from voles.he Giardia parasite originates from contaminated items and surfaces that have been tainted by the feces of an infected carrier. The symptoms of Giardia, which may begin to appear 2 days after infection, include violent diarrhea, excess gas, stomach or abdominal cramps, upset stomach, and nausea.