Can indoor air be hazardous to your health? No doubt about it. Exposure to air pollutants can be up to 100 times higher indoors than outdoors. The American Lung Association estimates that most people spend 90 percent of their time indoors, making indoor air quality (IAQ) a critical component of home comfort. Many common household items contribute to poor indoor air quality. Compounds found in carpeting, furniture, upholstery and drapery fabric constantly emit fumes. Other sources of pollutants can include cleaning agents, paints and personal care products. The tight construction of today's homes also contributes significantly to poor IAQ. Things like weather stripping and storm doors are designed to save on energy costs. However, they also prevent proper ventilation by keeping indoor air in and outdoor air out. The result can be a buildup of contaminants within the home. Poor IAQ can contribute to several health problems. Medical groups report that as many as half of all illnesses are caused or aggravated by indoor air pollution. Pollutants within the home can cause homeowners to suffer from flu-like symptoms such as headaches, nausea and respiratory irritation. As well, two existing health problems that can be helped by improving indoor air quality are allergies and asthma. By removing airborne dust particles, the amount of exposure the respiratory system has to them is reduced. Proper ventilation also plays an important role in improving indoor air quality, helping to reduce the concentration of pollutants inside the home.