Since outdoor air pollution from smoking can reach high levels for short time periods, there is the potential for acute health effects. Minor health effects include eye and respiratory irritation. Previous research has shown that even short exposures to air pollutants in cigarette smoke can be seriously harmful to children and adults, potentially leading to an increased likelihood of ear and respiratory infections, the onset or increased severity of asthma attacks, and a possible increased risk of myocardial infarction for those who already have some cardiovascular risk.