There are many pollution problems in buildings which can cause allergies. Because of more and more pollution, allergies are increasing. We are all exposed to numerous chemicals on a regular basis. Paint, fertilizer, fumes, and treated wood are just a few things that can cause health problems. We can also find several substances in water. The most common toxins in water are chlorine, fluoride, pesticides, copper, and lead. The main indoor allergies are mold, dust, and fungi. When you try to air out these allergens, you get more in. Mold can be in side or out so if you try to air it out you just airing it in. Also, if you put your clothes out to dry, they get mold on them and bring it in your house. Fungi grow on droppings and bodies of Dust-Mites. The Dust-Mites like warm places such as pillows and beds. These places are warm because the sweat from people gets in there. Dust is another allergen. Dust is usually found in garages. Sweeping up dust will bring it up into the air.