Occupational Hazards in the Health Professions

Dag K. Brune, Christer Edling

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9780849369315
• eBook ISBN: 9781000142006
• Topic: Law
• Subtopic: Industrial Design
• Index: Law

This volume is written especially for health professionals affiliated with hospitals, veterinary clinics, dental offices, dental laboratories, toxicological testing laboratories, and pharmaceutical laboratories as a contribution to attain security in such working environments. Possible hazards in the working environments for the health professionals are discussed, followed by recommendations of the various precautions that may be taken to avoid these hazards. The possible hazards in hospitals discussed are ergonomics, physical hazards, chemical hazards, and bacteriological risks. The ergonomics, chemical hazards, and bacteriological risks for dental offices and veterinary clinics are also explained.

Chapter 1

GENERAL CONCEPTS

Per Lundberg

TABLE OF CONTENTS

I.	Introduction
II.	Exposure Limit Values and Risk Management
III.	Halothane, Exposure Limit Values
IV.	Nitrous Oxide, Exposure Limit Values
V.	Occupational Standards Other than Exposure Limit Values A. Anesthetic Gases B. Cytotoxic Drugs
VI.	Monitoring Exposure Levels
VII.	Concluding Remarks
Appendix: Useful Addresses
References

I. INTRODUCTION

In this chapter, a few examples are given of substances which might involve a risk for the health professionals. The hazards of these chemicals will be dealth with in more detail elsewhere in this book, as will the hazards of, for example, inorganic mercury in dental offices and formaldehyde in pathological departments. The examples given are merely to illustrate different ways of providing occupational standards and to point out that there exist some national differences in regulating the work enviroment.

The basis for providing occupational safety for health professionals is the same as for occupational safety for the working environment as such. The regulatory authorities provide occupational standards which may be recommendations or which may have a legal status. Usually, in the area of occupational health, one thinks of standards in terms of exposure limit values for workplace contaminants, but standards may, for example, involve requirements of the best available technology.

II. EXPOSURE LIMIT VALUES AND RISK MANAGEMENT

Laws, recommendations, stipulations, and engineering standards, etc. for acceptable and permitted levels of chemicals in workroom air have been published during the last 50 years. Such lists exist in more than 70 countries. However, few countries generate or update their lists independently. The expression “exposure limit value” is used here as a general term and will therefore cover the various expressions employed in the national lists, such as “maximum allowable concentration”, “threshold limit value”, “permissible level”, “limit value”, “average limit value”, “permissible limit”, “time-weighted average”, “industrial hygiene standard”, etc. The definition of these various expressions is given in the separate national lists, but it should be noted that the same terms are used with different meanings. As an example, the expression “maximum permissible concentration” in certain countries indicates ceiling values, whereas in others it defines average concentrations.¹

The risk management underlying the occupational exposure limit values can be divided into four steps:

1. Risk identification

2. Risk estimation

3. Risk evaluation

4. Risk control

At least the first two steps are scientific issues and the last two are political and administrative in nature. It is important to realize that risk management is a focus for the driving forces of society. This fact also makes a simple comparison of exposure limit values from different countries partly misleading. Within the context of different health policies and differences in technical development and economic capacities, national exposure limit values will differ. However, all countries can strive to achieve a common scientific approach in a standard setting.

In the first phase in setting exposure limit values, experts evaluate the current knowledge on a toxic compound. Knowledge of the adverse effects of many toxic substances is, however, limited. Furthermore, the conclusions drawn are often based on the effects of short-term experiments only. Consequently, long-term effects such as carcinogenicity and neurobehavioral effects may not have been considered. In the second phase of the establishment of an exposure limit value, technological and economical consequences are considered. The final value is thus usually a compromise between the medical/toxicological, technical, and economical points of view which means it is the result of political decision making. Exposure limit values should therefore be considered primarily as administrative norms. They may have a legal status or be recommendations. They should never be used as fine lines between safe and dangerous concentrations. They rather reflect exposures accepted by the society.

The scientific parts of the risk management should deal with published scientific literature only. The assessment should aim to describe dose-effect relationships, dose-response relationships, and the critical effect. These concepts can be defined as follows. Dose-effect relationship means a factor-specified relationship between dose or exposure and the degree of effect on the individual level. Dose-response relationship describes a factor-specific relation between dose or exposure and the frequency of affected individuals. A dose-response relationship can be obtained for different types of effects, such as irritation, peripheral neuropathy, or cancer. A critical effect, finally, may be defined as that particular effect which appears earliest or at the lowest exposure level. The critical effect could be any adverse and unwanted effect and is not merely the most dramatic effect. With this use of the concept, the best prevention to any acute or chronic change will be obtained.

The documentations of the medical/toxicological considerations are published in some countries. For example, the American Conference of Governmental Industrial Hygienists (ACGIH),² the Federal Republic of Germany,³ and Sweden⁴ yearly publish a documentation for new or revised exposure limit values. The techological and economical considerations are usually not publicly documented. The ACGIH is an association of scientists and hygienists within the occupational health sciences. They publish annually an unofficial list of exposure limit values, called threshold limit values (TLVs). The ACGIH values are only intended as recommendations and do not represent the official U.S. occupational exposure limits, although some of their values have been adopted by the Occupational Safety and Health Administratio (OSHA) as official values for the U.S.

Except for the documents specifically written in connection with national exposure limit values, evaluated information on health hazards is produced by some international bodies. The International Program on Chemical Safety (IPCS) is a joint venture of the United Nations Environmental Program, the International Labor Organization (ILO), the the World Health Organization (WHO). WHO, under this joint sponsorship, publishes environmental health criteria, where ad hoc expert groups evaluate the health effects of chemicals. The WHO also publishes technical reports where some of them also give recommendations for health-based occupational exposure limits. The International Agency for Research on Cancer (IARC), within the WHO, evaluates the carcinogenic risk of chemicals to humans, presented in a series of monographs. Here, too, the evaluation is made by ad hoc expert working groups. (Some addresses to distributors of the different documents mentioned here are given in the Appendix to this chapter.)

A large body of scientific articles and reviews has, during the last decades, been published concerning interpretation and management of exposure limit values; some examples are given in the reference list.^{5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25} Whatever numerical value an exposure limit is given, it should never be regarded as a borderline between safe and dangerous concentrations. The best practice is to maintain concentrations as low as possible. The differences between different countries can be exemplified by a couple of substances occurring in the work environment of health professionals.

III. HALOTHANE, EXPOSURE LIMIT VALUES

Halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) is used as an anesthetic gas, usually together with other halogenated anesthetic gases or nitrous oxide. The introduction of the 1986–1987 ACGIH TLV Booklet²⁶ states: “Threshold limit values refer to airborn concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect. Because of wide variation in individual susceptibility, however, a small percentage of workers may experience discomfort from some substances at concentrations at or below the threshold limit”. The time-weighted average exposure limit in the ACGIH 1986–1987 TLV booklet²⁶ for halothane is given the value of 50 ppm (400 mg/m³). Halothane is placed in the list under “Notice of Intended Changes”, where it has been since the 1984–1985 list. It means that it is not yet adopted, but is co...

Table of contents

• Cover
• Title Page
• Copyright Page
• Preface
• Editors
• Contributors
• Table of Contents
• Chapter 1 General Concepts
• Chapter 2 Occupational Injuries and Diseases
• Chapter 3 Indoor Climate
• Chapter 4 Human Immunodeficiency Virus (HIV)
• Chapter 5 Microbiological Hazards
• Chapter 6 Anesthetic Gases
• Chapter 7 Antineoplastic Agents
• Chapter 8 Methyl Methacrylate
• Chapter 9 Histopathological Laboratories
• Chapter 10 Radiation Hazards
• Chapter 11 Biomechanical Aspects of Bodyloading During Work and Sport
• Chapter 12 Ergonomics for Health Professionals in Hospitals and the Community
• Chapter 13 Eczema
• Chapter 14 Hazards in the Dental Environment — Curing Lights and High-Speed Handpieces
• Chapter 15 Effects of Vibration in the Hands
• Chapter 16 Mercury in Dentistry
• Chapter 17 Risks and Prevention of Musculoskeletal Disorders Among Dentists
• Chapter 18 Dental Laboratories
• Chapter 19 The Psychosocial Working Environment
• Index