Hi Steve
Just one of the many problems that can be exacerbated when people look at each different type of risk in isolation and don't look at the overall picture.
I do think there ARE occasions when it makes sense to focus in one type of risk on its own, as long as the findings of that assessment are then integrated into an overall assessment of working conditions.
This particular issue is made more difficult in part due to the continuing emphasis of many organisations AND their Safety Bods on treating occupational health risks as an afterthought at best.
Add in the fact that one has to play two separate numbers games - 1. What the noise exposure is and 2. What the exposure (via variious routes) to hazardous substances is, with lots of IFs and BUTs to consider and it would be very tempting to just put the issue into the "too difficult" box.
Overall I think that as a society in Britain (and other places) we continue to give far too little attention to occupational health risks, and perhaps in part that is because the rules are less easy to define as simple rules.
When the first EC Directive on occupational exposure to noise was still being negotiated I got the job of accompanying "The Minister" on a factory visit and at the end of that visit the predictable debate took place about where the "first" and "second" "action levels" should be set [but equally predictably no debate about where the "peak action level" should be set.
So the consensus would end up at 85dB(A) and 90 dB(A) each as an 8 hour Time Weighted Average at a time when the scientists were saying broadly (I can't remember the Standard Deviations on the numbers which were presumably "central estimates") if we exposed a worker to 85dB(A) for a working life of 40 hours a week, and 40 years then they had an 11% chance of sustaining significant hearing loss, with that percentage going up to 25% (one in four!!) if the level was at 90dB(A).
We would never have a debate about a machine that had a more than one in ten chance of signficantly injuring a worker if they worked on the machine for their lifetime - we would say "guard it PROPERLY"!!
In contrast there is a tendency to be less robust when it comes to the occupational ill health which might not present for months, years or decades.
Of course, a few years later than my day with "The Minister" the EC got round to negotiating a second Directive on occupational exposure to noise and the regulatory levels came down to 80 and 85dB(A) - which translates as saying that we STILL think that it may be OK to give a worker a more than one in ten chance of sustaining signficant hearing loss over a lifetime.
Which in itself is hard to swallow. You are now reminding us that there are also other factors at play. Those perhaps even easier to assign to the "too difficult" box.