Pollen - when ingested into the human body causes the immune system to produce large amounts of antibodies, which in turn causes chemicals such as histamines to be released. The release of these chemicals cause the body to have symptoms such as sneazing, runny nose, and watery eyes.  

Mold Spores - when mold found in wood, ceiling tiles, wallpaper, paint, carpet, sheet rock, and insulation is distrubed mold spores are released into the air. Mold spores can cause symptoms such as sneazing, runny nose, and itchy or watery eyes.

Dust Mite Debris - a combination of dead skin and dust mite feces, this debris lives in our beds, chairs, couches, and our children's stuff animals. Dust Mite Debris is almost as effective as pollen at causing symptoms such as sneazing, running nose, and watery eyes.

Smoke - cigaratte, cigar, fireplace, and wood burning stove smoke contain very tiny particles composed of wood tar, gases, soot, and ashes that can cause severe irritation and allergic reaction in some people and even trigger bronchitis or asthma attacks in others. Smoke also contains carcinogens which could also lead to lung disease and cancer.

Pet Dander - tiny pieces of skin that come off of your dog or cat when they scratch. This dander either floats, suspended in the air or tick to whatever they land on. Allergies to pet dander can be very serious including symptoms such as swollen eyes and throat, watery eyes, runny nose, sneazing, coughing, wheezing, or even asthma attacks.

Household Dust - dust accumulates everywhere in your home; carpets, tables, TV screens, clothes, walls, ect. Simply walking around in your home may disturb or "stir up" dust into the air which can irritate your immune system.

Smog - even if you live in the remote countryside in a small town with little to no industry chances are the air in your home contains smog. Smog, a combination of smoke and fog, makes its way from urban/industrial areas of the world right to your doorstep on the wind. Breathing in smog for pro-longed periods of time can not only cause allergic symptoms such as watery eyes, and running nose, but also more serious respiratory issues such as wheezing, coughing, asthma attack, and sore throat.