CHAPTER 4EVALUATION OF EXPOSURE TO CHEMICAL AGENTS
JERRY LYNCH† and CHARLES CHELTON
30 Radtke St., Randolph, NJ, 07869
4.1 SAMPLING STRATEGY
This chapter explains why workplace measurements of air contaminants are made, discusses the options available in terms of number, time, and location, and relates these options to the criteria that govern their selection and the consequences of various choices.
A person at work may be exposed to many potentially harmful agents for as long as a working lifetime, upward of 40 years in some cases. These agents occur singly and in mixtures, and their concentration varies with time. Exposure may occur continuously, at regular intervals, or in altogether irregular spurts. The worker may inhale the agent or be exposed by skin contact or ingestion. As a result of exposure to these agents, they come in contact with or enter the body of the worker, and depending on the magnitude of the dose, some harmful effects may occur. All measurements in industrial hygiene ultimately relate to the dose received by the worker and the harm it might do.
Changes in working conditions, in technology, and in society have changed old methods of measurement:
- With few exceptions, workplace exposure to toxic chemicals is much below what is commonly accepted as a safe level.
- As a consequence of the reduction of exposure, frank occupational disease is rarely seen. Much of the disease now present results from multiple factors, of which occupation is only one.
- Workers have ...