That doesn't sound like much, a small increase, but if you consider how many people are at risk for stroke, the absolute increase in incidence can be quite high.

Taken together with previous work, these results support the idea that reducing exposure to particulate matter may reduce the risk of strokes and heart attacks.

People have discovered the word risk again,

People in the most vulnerable areas clearly anticipated their cars, like their homes, would be at risk, ... It's suggestive of people taking their cars, not because they had a lot of people to protect, but because they were taking their second-most valuable possession.

Those people at risk should not get on the highways to evacuate. People should prepare to shelter in place if they have not evacuated.

The increased risk was higher if you didn't have severe blood pressure, so presumably in people who've already got bad blood pressure, that's the main risk factor,