It's important to understand that activated carbon filters don't remove bacteria, viruses, fungus, or fungal spores from water. They only filter out small particles such as metals, pesticides, and other chemicals. Viruses are too large for the pores in most filters to filter out. However, studies have shown that carbon filters can reduce the number of virus particles in water by up to 99%. This means that a water treatment plant using carbon filters in its process could reduce its viral load by up to 1 million particles per gallon. Viruses are responsible for many illnesses that people get called sick days. Some viruses cause symptoms that people may misinterpret as something else. For example, a person might feel nauseated but not know that it is because they have the stomach flu. Other viruses can be diagnosed using tests done on blood samples or through tissue samples taken during surgery. There are vaccines available to protect people against some viruses but not all people will develop antibodies after being vaccinated. Activated carbon is used in water treatments plants to filter out certain chemicals from water. It works by adsorbing or binding to those chemicals through chemical interactions between the carbon and the molecules inside the water. The carbon is then removed from the water system along with any other waste products from sources such as sewage treatment plants.