Is breathing smog harmful

Long term exposure to smog laden air can lead to various lung conditions such as Asthma, bronchitis, emphysema, and even lung cancer, (depending on what is in the air). Short term exposure can exacerbate asthma and/or bronchitis, wearing a mask can help some but many components of smog are too small to be filtered by most masks. During a smog alert people with cardiac or respiratory conditions are cautioned to remain indoors, air conditioned buildings offer some protection.