Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. ---- Previous studies have linked exposure to environmental pollution to an increased risk of heart problems, but the two analyses now show that poor air quality can lead to a heart attack or stroke within as little as a few hours after exposure. Scientists found that people exposed to high levels of pollutants were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure.