Cooking over a traditional open fire or mud stove can cause increased health problems brought on from the smoke, particularly lung and eye ailments, but also birth defects. The health problems associated with cooking using biomass in traditional stoves affect women and children most strongly, as they spend the most time near the domestic hearth. Replacing the traditional 3-rock cook stove or mud stove with an improved one and venting the smoke out of the house through a chimney can significantly improve a family's health. There are many well-documented adverse health effects of exposure to pollutants from indoor cookstoves, including acute respiratory infections (ARIs), chronic obstructive pulmonary disease (COPD), pulmonary tuberculosis (TB), cataracts, low birth weight (LBW), increased perinatal and infant mortality, nasopharyngeal and laryngeal cancer, and lung cancer. It is estimated that 4% to 5% of the global mortality and disability adjusted life-years (DALYs) are from ARIs, COPD, TB, asthma, lung cancer, ischemic heart disease, and blindness attributed to solid fuel combustion when cooking in developing countries.