Certain immediate effects are similar to those from cold or flu. It is often difficult to determine if the symptoms are a result of exposure to an indoor are pollutant. Effects may show up after a single exposure or repeated exposures. These include irritation to the eyes, nose, throat, headaches, dizziness, and fatigue. These effects are usually short term and treatable. There are several diseases, which have been linked to indoor air pollution, these include asthma, hypersensitivity, pneumonia, humidifier fever, and lung cancer.