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.
The primary cause of Giardia is the result: 1  of eating food from an animal infected with an infectious agent, or from food that is contaminated from the food handler (who is infected with Giardia), or from contaminated soil or water, or from toxins produced by an infectious organism.