Is my 8mm film ruined? ?

A lot of it will be, though the film that was still rolled into each spool may be ok, or just slightly fogged on the edges.

Unless it is "super eight" film, i.e. in a cartridge, it is actually 16mm film, the 8mm movie camera exposes onto half of the 16mm film width, when it finishes, the film spool is taken out & flipped around, then exposed on the other side. In developing they slit the film down the middle & join them up.

My point is that the rolls are designed to be open in subdued lighting, to swap over the reels halfway.

The film rolls tight enough, not to fog the edges.

However, the film is probably old & the emulsion may be already ruined from age.

If the film was a bare roll, not in a cassette or cartridge, then 4 seconds is a few thousand times more light then the film can stand - it is ruined.