Abdominal Cramps and Car Exhaust

Factual Questions
1

I remember when I used to work around idling cars I got a lot of abdominal cramps and that I was also really drowsy after working.

Also, today, when jogging, I passed by a lot of cars down a stretch of road, and shortly thereafter, I got painful abdominal cramps and I had to stop jogging.

Was this all due to car exhaust fumes?

If so, why? Is it because the car exhaust is causing an oxygen deficit in my blood?

2

Here is a link that list some of the harmful effects of vehicle exhaust emissions. I don’t see any reference to the problem you described, but IANAMD. Perhaps one will wander by and offer an informed opinion.