Studies in Montreal and Santiago, Chile, found an increase in headache-induced hospital visits when nitrogen dioxide and carbon monoxide levels were especially high. Scientists point to pollutants' inflammatory effects on blood vessels.
The chemicals from fuel combustion have been shown to cause inflammation in general, which could help explain why a group of Canadian researchers found evidence that air pollution may trigger appendicitis.
High Blood Pressure
When University of Michigan researcher Robert Brook, MD, exposed healthy adults to particulate matter levels common on a typical day in Detroit, their diastolic blood pressure shot up several points—and the effects lasted up to 24 hours. The pollutants are thought to trigger a fight-or-flight-like response in the nervous system; as arteries constrict, blood pressure spikes.
Type II Diabetes
A study published in 2010 followed 1,775 middle-aged women in Germany's Rurh district, which is home to heavy traffic. After 16 years, the women were most likely to develop type II diabetes if they lived within 100 yards of a busy road.
Scientists in Canada have discovered that postmenopausal women living in areas with high levels of nitrogen dioxide may face at least a 25 percent higher chance of contracting the disease. Other research suggests that prolonged exposure to toxic emissions around the time of a woman's first period or first pregnancy may also increase risk.
Next: What you can do to avoid inhaling noxious fumes