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Scope and Practice of Industrial Hygiene and its Relevance to Occupational and Environmental Health

Pranjal Jyoti Goswami

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A hazard is anything with the potential of producing an adverse outcome and is omnipresent in industries. The hazards may be chemical (dust, fibers, vapors, fumes, gas etc.), physical (noise, temperature, radiation etc.), biological (bacteria, fungi, viruses etc.) ergonomic and psychosocial. Unfortunately, a hazard is not identified until an accident or adverse incident occurs. Proactive approach of Industrial Hygiene profession enables the industries to identify hazards well in advance of an adverse/ unwanted occurrence and minimizes the risks. An Industrial Hygienist by virtue of special studies and training acquires competence and ability to recognize and evaluate occupational hazards and to understand adverse effect of exposure. Such a person has the capability to specify corrective measures to minimize or control occupational and environmental hazards.

Industrial Hygiene is defined by American Conference of Governmental Industrial Hygiene (ACGIH) as “that science and art devoted to anticipation, recognition, evaluation and control of those environmental factors or stresses arising in or from the workplace, which may cause sickness, impaired health and well being, or significant discomfort among workers or among the citizens of the community.”

Many hazardous substances have been banned from being used in industry and many other are still being used in industries. Exposure to these substances beyond a certain limit has the potential to induce occupational diseases. Occupationally related illnesses like lung diseases, kidney disorders, reproductive disorders, central nervous debilitation, cancers etc. still occur extensively in industries. Occupational disease resulting from exposure often goes unrecognized or underestimated because the causes are not immediately apparent. Majorities of occupational health hazards are arising from inhaling chemical agents in the form of vapors, gases, dust fumes etc. or by direct skin contact. Harmful agents may also enter the body by the route of ingestion. The degree of effect of an agent primarily depends on nature, dose and duration of exposure.

Recognition and evaluation of hazards at workplaces require a systematic procedure. Walk-through surveys, chemical inventories, equipment and process reviews are used to identify and evaluate employee exposures qualitatively. Sampling or quantitative evaluation of magnitude of risk constitutes a significant element in industrial hygiene program. Physical, chemical and biological hazards can by assessed quantitatively and the results can be compared with recommended standards. The most widely followed exposure standards are Threshold Limit Values (TLV) and Biological Exposure Indices (BEI) set by ACGIH.

Air borne chemical hazards can be effectively monitored by applying specific air sampling methodology. Different instrument and chemical specific air sampling media such as membrane filters, sorbent tubes are used in sampling. The collected samples can be analyzed by NIOSH or OSHA prescribed analytical methods. To obtain representative samples the workplace has to be characterized for selecting homogeneous exposed group. The factors account for during sampling procedure are air flow rate and sampling duration. Pre-calibrated equipment like sound level meter, luxmeter, globe thermometer etc. are used to evaluate the magnitude of physical hazardous agents at workplace. A qualified Industrial hygienist is capable of carrying out quantitative exposure assessment in industries.

When hazardous agents concentration exceed the recommended limit, control measures have to be implemented. Hierarchy of control elimination, substitution, engineering control, administrative control and personal protective equipment should be used as guidance and the most practical and cost effective means of control has to be chosen. An Industrial Hygienist can recommended the best possible control measures according to the situation at the workplace.

A thorough understanding of exposures allows the prioritization of occupational hygiene program in prevention of occupational illnesses. Recognizing the hazards, assessing the risks and controlling those hazards to an acceptable level will provide the best economic solution to a healthy workplace. The ultimate objective of industrial hygiene is to improve health, morale of workers and productivity.


  1. Fundamentals of Industrial Hygiene, Third Edition-National Safety Council
  2. Occupational Health and Hygiene, Guidebook for the WHSO- January 1992, by David Grantham.
  3. The Occupational Environment- Its Evaluation and Control, A publication of American Industrial Hygiene Association, Edited by Salvatore R. DiNardi-1998.

Pranjal Jyoti Goswami- Industrial Hygienist, COEH

Published in: Bulletin of Occupational And Environmental Health
Vol. No.4 Jan-June 2003

Industrial Hygienist, COEH