Principles of Occupational Health and Hygiene

An introduction

Sue Reed, Dino Pisaniello, Geza Benke, Kerrie Burton

• Éditeur: Routledge
• Année: 2020
• ISBN:
  9781000246872
• Édition: 2
• Sujet: Medicine
• Sous-sujet: Public Health, Administration & Care

Today's workplaces are full of materials and processes which are potentially hazardous to our health. Industry depends on a large range of naturally occurring and synthetic materials, many of which can adversely affect the health of the workers. Even some non-industrial workplaces can contain hazardous materials or cause exposure to physical or biological agents that can be harmful to health. Principles of Occupational Health and Hygiene offers a systematic and comprehensive overview of occupational health hazards and hazardous environments encountered in a range of industries and organisational settings.Leading industry professionals and educators explain how to identify key workplace hazards including chemical agents such as dusts, metals and gases; physical agents such as noise, radiation and extremes of heat and cold; and microbiological agents. They outline assessment procedures and processes for identifying exposure levels. They also explain how to evaluate risk and follow safety guidelines to control and manage these hazards effectively.Chapters are heavily illustrated with detailed case studies, diagrams, flowcharts and photos. Practical guidelines are provided for managing each hazard type. The second edition has been extensively revised and updated, with new chapters on industrial ventilation, personal protective equipment and emerging issues in the field, and reflects the recent changes in Workplace Health and Safety legislation relating to the hazards discussed. Principles of Occupational Health and Hygiene is an ideal resource for students of Occupational Health and Safety, and a professional reference for Occupational Hygienists, Occupational Health and Safety professionals, and anyone working in an Occupational Health and Safety role.

1.
The hazardous work environment:

The hygiene challenge

Dr David Grantham AM

1.1 Introduction

1.2 Historical background

1.3 The present

1.4 The serious problem of underestimation of occupationally related disease

1.5 Occupational hygiene

1.5.1 Definition

1.6 Recognition of health hazards in the workplace

1.6.1 Direct health indicators

1.6.2 Using previous experience and information already available

1.6.3 Observation or use of specialist expertise

1.6.3.1 The material inputs

1.6.3.2 The process

1.7 Use of the preliminary or walk-through survey

1.7.1 Some typical processes targeted for health hazards in walk-through inspections

1.8 Evaluation

1.8.1 Evaluating the risks from a hazard

1.8.2 Some typical evaluations

1.8.2.1 Example of a simple evaluation

1.8.2.2 Examples of an evaluation requiring some basic workplace monitoring

1.8.2.3 Example of a complex evaluation requiring outside assistance

1.9 Control

1.10 The occupational hygiene flowchart

1.11 References

1.1 INTRODUCTION

Occupational hygiene can be considered as the fundamental process skill required for achieving good health outcomes in workplaces where there are chemical, biological and physical agents. It is often difficult to recognise health hazards in workplaces, and historically it has been difficult to control workplace conditions so as to achieve acceptable health outcomes even when the problems are identified. Examples of classic occupational health hazards from everyday workplaces past and present demonstrate the extent of these problems. This chapter presents an overview of occupational hygiene and procedures for OHS investigations, and lays out a framework for considering all the topics covered in this book.

1.2 HISTORICAL BACKGROUND

Today’s workplaces frequently contain a variety of materials and processes that are potentially hazardous to health. Industry depends on a large range of naturally occurring and synthetic materials, many of which can adversely affect the health of workers handling them.

The histories of many trades and workplaces have included traumatic injury, disease and death. The Industrial Revolution moved most workers from lives of agrarian poverty to perilous existences in new trades and industries whose founders had little or no understanding of the hazards they posed. Mining the coal needed to fuel steam-powered factories produced accidents and fatalities on an unprecedented scale. Many of those who survived injury or escaped death in the mines became ill from dust diseases. In mines, mills and factories, inexperienced workers, including children as young as six, faced injury or death from machinery that was designed for output, not safety.

Improvements to workplace conditions came slowly. It was not until 1833 that the first real labour laws and the Factory Inspectorate were established in the United Kingdom.

Some factory and mill owners operated exemplary establishments which took account of the general safety and health and welfare needs of their workers, but these were in the minority. With the development of chemical-based industries in the late 19th and early 20th centuries, many new occupational diseases emerged, some of which continued unchecked until relatively recent times. This was despite readily available evidence of the hazards. Occupational diseases commonly associated with mining (pneumoconiosis or dust diseases), fur carroting (mercurialism) and chimney sweeping (scrotal cancer) became accepted as ordinary risks of these jobs. It was not until after the First World War that significant technical and medical resources became available and were brought to bear on a wide range of occupational diseases. Workplace legislation to adequately protect the health of workers has lagged well behind medical and epidemiological discoveries about the health risks of many occupations and the hazards posed by the materials they use.

1.3 THE PRESENT

Society does not expect workers to trade away their health and safety just to have a job, but occupationally related illness can still occur in many workplaces, and not just in industrial ones. Chemicals that can potentially cause cancer, lung diseases, blood and bone disorders, loss of mental ability, central nervous system debilitation, infertility or death are still found in factories or on farms. Microbiological hazards contribute to poor indoor air quality, and can present significant risk of disease transmission in childcare centres, hospitals and other workplaces where accidental body-fluid exchange can occur. Animal husbandry or contact with creatures such as birds and bats can all present workplace risks of transmissible zoonotic disease. Industrial workplaces can also impose physical and mental strains, such as manual handling, noise, vibration, extremes of heat and cold, and both ionising and non-ionising radiation. Humans have no natural protection against extreme exposures to any of these hazards, which help make many workplaces potentially unhealthy.

Some occupationally related disease is a legacy of previous inaction, but new cases of well-recognised occupational diseases still occur because of failure to implement known, and often simple, control techniques. The body of knowledge on common hazards in the workplace is now extensive and ignorance is rarely a plausible excuse for a lack of controls.

Commonly recognised hazards include:

• use of leaded solder in radiator repair
• welding, which produces gases and metal fumes
• vehicle exhaust emissions, which produce carbon monoxide
• excessive ultraviolet radiation exposure from working outdoors
• agricultural use of pesticides and herbicides
• noisy and vibrating machinery
• dust from crushers in stone quarries.

In these cases, the hazard is fairly widely recognised. For example, most people know that lead can be poisonous, that car exhaust fumes are dangerous, that pesticides can be harmful to humans as well as pests, and so on. What remains unrecognised is the extent to which a person’s health can be jeopardised if they receive excessive exposure to these hazards day after working day.

Some less commonly recognised workplace health hazards occur with:

• laser printers producing nanoparticles
• sterilising chemicals used in hospitals
• non-ionising radiant energy from radio-frequency furnaces and heaters
• ‘sick’ air-conditioned buildings
• water-cooling towers of air-conditioning plants which can promote growth of Legionella bacteria.

In these cases, the hazard and the exposure may go unrecognised by both employer and worker.

While employers in Australia (now more widely referred to as PCBUs, or persons in control of a business or undertaking) have the primary responsibility for implementing safe working practices, government has the task of providing guidelines through appropriate laws, practical regulations and codes of practice. Early efforts by legislators and employers were often ineffectual, although there have been some spectacular successes. The prevalence of coal workers’ pneumoconiosis, which was as high as 27 per cent in Australia before the Second World War (Moore & Badham 1931), and 16 per cent in 1948 (Glick 1968), had been reduced to virtually nil by the turn of the 21st century thanks to the concerted long-term application of dust control through ventilation.

Throughout Australia (as in much of the industrialised world), the states and territories have introduced modern occupational health and safety laws and regulations intended to promote acceptable, achievable and enforceable programs which will usher in the required changes. Professional health and safety (H&S) practitioners now play a vital role in ensuring that good guidance is provided to employers in managing the risks from health hazards in the workplace. But their task goes beyond merely ‘providing good guidance’. How does the H&S practitioner provide the proper guidance for minimising exposure to hazards that cannot be seen, felt or smelled—that are undetectable by the senses?

1.4 THE SERIOUS PROBLEM OF UNDERESTIMATION OF OCCUPATIONALLY RELATED DISEASE

Is work-related ill health important enough to deserve the attention it now receives? The last two to three decades in Australia have witnessed an expansion of occupational-health laws and regulations, with greater government administration and new inspectorates, though the process of harmonising state laws is slow. There are mountains of technical guides, numerous training programs and expanded legal services. The numbers of OHS professionals and research programs are growing. But are workplace hazards—from chemicals to conditions—really detrimental to health? After all, there are relatively few ill people in any given workplace. When a disaster like a mass drowning, a rail crash or an explosion occurs, it is easy to count the bodies. In contrast, occupational disease resulting from exposure to a hazardous chemical or a damaging physical agent (such as noise or radiation) often goes unrecognised. This makes it easy to underestimate the problem. Because it can take a long time for occupational diseases to develop, their causes are often not immediately apparent. Many similar illnesses are also the result of lifestyle or social conditions. Workers move away or change jobs or retire. A sick worker’s doctor may simply be unaware of the kind of work that his patient does or has done in the past. Historical records of occupational hazard exposures are rare, although the new laws now mandate record-keeping in some cases.

Reliable data on the contributions of workplace conditions to ill health in the community have traditionally been difficult to assemble, and this is a worldwide problem. Even data on compensation for work-related ill health is lacking, and this lack gives a misleading impression of the true prevalence of occupational disease. Most work-related ill health is the result not of accidents (falls, high-energy impacts, crushing or piercing injuries, etc.) but of exposure to hazardous chemicals or environmental conditions. The findings of epidemiological studies, sometimes years after exposure first commenced, have confirmed the need for the controls now widely demanded by laws and regulations. Consider the following examples:

• World’s worst single-event industrial disaster (with the probable exception of Chernobyl): At Bhopal, India, in 1984, the inadvertent release of methyl isocyanate gas (an intermediate of manufacturing a pesticide) killed more than 3000 people and injured some 17 000 more who lived in the environs of the chemical factory. Though the cause of the disaster was soon evident, its true scale was not so immediately obvious.
• The United States’ worst individual industrial accident: Hawk’s Nest Tunnel in West Virginia, built to divert a river in the early 1930s, required drilling through silica rock. As a result of inhaling the resulting dust, more than 600 men died from silicosis. The affected workers became ill and died within two to six years. Neither the cause of the illness nor its true prevalence...