problem 1:

What are the two major types of industrial ventilation which are employed to control airborne contaminants in a work environment? Name all three distinctive conditions where the two techniques of ventilation can be suitably employed correspondingly.

In general terms, what are the situations for which each system would be a proper technique of control and the particular action required to aid overcome four major shortcomings?

problem 2:

Describe what is meant by the term Threshold Limit Values (TLVs). describe in brief the different TLVs employed by Industrial Hygienists.    
Outline the strengths and weaknesses of these occupational exposure limits and exemplify how they may best be used as part of a whole control strategy for hazardous substances.

problem 3:

You are the registered Safety and Health Officer of a textile milling factory. The Occupational Safety and Health Inspectorate have told your management which the workforce has a probable overexposure to noise. The reaction of management is to ask you to issue ear protective devices to employees.

How would you evaluate the noise problem at the factory and what control measures would you consider before you suggest  the supply of hearing protection to personnel exposed to high intensity noise ?