That dust and chest infections

[Poppiecock]

Is it just a coincidence, or has working in that dust-bowl for 3 days contributed to me being off sick today as I can barely speak and I'm hacking up my lungs almost constantly?

Admittedly, being in touch with the great unwashed for 4 x 12 hour days could have put me in contact with someone carrying an infection, but I do wonder if the dust is the main reason? - many car park marshals were wearing dust masks this year.