interesting concept here, but really many times these workers may be experiencing high levels of stress from noise and air pollution, so realistically this could be a worthwhile approach to mitigating some of the effects elicited from such forms of pollution.

How would we know the levels of effect or even more specific the level/amount of hormones or chemicals being released from such harsh/ difficult occupational environments

I would be all for something like this, so long I knew ahead of time and also if the equipment was tested, regulated and properly equipped with full safety and precautionary measures regarding human health.