Occupational Health and Hygiene in Industries

Chapter 1

Industrial Hygiene

1.1 History

There has been an awareness of industrial hygiene since antiquity. The environmental and its relation to worker health was recognised as early as fourth century BC when Hippocrates noted lead toxicity in the mining industry, in the first century AD, Pliny the Elder, a Roman scholar, perceived health risks to those working with zinc and sulphur. He devised a face mask made from an animal bladder to protect workers from exposures of copper miners to acid mists.

In 1713 Bernardino Ramazzini published the first book that could be considered a complete treatise on occupational diseases, De Morbis Artificum Diatriba. From his own observations he accurately described scores of occupations, their hazards, and resulting diseases. Although he recommended some specific as well as general preventive measures (workers should cover their faces to avoid breathing dust), most of his control recommendations were therapeutic and curative. While he had a vast knowledge of the literature of his time, it has been suggested that many of the works he cited were of questionable scientific validity, and some were more myth than science and should have been recognized as such even in Ramazzini’s time. Because of his prestige these fanciful notions must have received wide acceptance and because his book was so admired, Ramazzini’s influence may have stifled progress in his field during a period when great advances were being made in other branches of medicine. Nevertheless, his cautions to protect workers and his admonition that any doctor called on to treat patients of the working class ask What occupation does he follow? earned him the appellation "Father of Industrial Medicine".

For more than 100 years following Ramazzini’s work, no significant additions to the literature on occupational medicine were published. In the nineteenth century two physicians, Charles T. Thackrah in England and Benjamin W. McCready in America, began the modern literature on the recognition of occupational diseases. McCready’s book, On the Influence of Trades, Professions, and Occupations in the United States, in the Production of Disease, is generally recognized as the first work on occupational medicine published in the United States. The recognition of a causal link between workplace hazards and disease was a key step in the development of the practice of industrial hygiene. The observations by physicians, from Hippocrates to Ramazzini and extending into the twentieth century, of the relationship between work and disease Vernon E. Rose, Dr PH, CIH, CSP, PE History and Philosophy of Industrial Hygiene of occupational medicine.

Fig. 1.1 Bernardino Ramazzini

The crystallization of the practice of the profession can be traced to simultaneous developments in Great Britain and the United States in the late nineteenth and early twentieth centuries. While legislation controlling working conditions was enacted in England beginning in 1802, the early laws were considered totally ineffective, as no proper system of inspection or enforcement was provided.

The British Factories Act of 1864, however, required the use of dilution ventilation to reduce air contaminants, while the 1878 version specified the use of exhaust ventilation by fans. The real watershed in industrial medicine and hygiene, however, came in the British Factories Act of 1901, which provided for the creation of regulations to control dangerous trades. The development of regulations created the impetus for investigation of workplace hazards and enforcement of control measures. In the United States in 1905, the Massachusetts Health Department appointed health inspectors to evaluate dangers of occupations, thus establishing government’s role in the nascent field of occupational health. It has been suggested that industrial hygiene did not "emerge as a unique field of endeavour until quantitative measurements of the environment became available.

But in 1910 when Dr. Alice Hamilton went, in her own words, as a pioneer into a new, unexplored field of American medicine, the field of industrial disease Worker exposures to many hazards (e.g., lead and silica) were so excessive and resulting diseases so acute and obvious, the evaluation step of industrial hygiene practice required only the sense of sight and an understanding of the concept of cause and effect. This champion of social responsibility" for worker health and welfare not only presented substantial evidence of a relationship between exposure to toxins and ill health, but also proposed concrete solutions to the problems she encountered.

On an individual basis, Dr. Hamilton’s work, which comprised not only the recognition of occupational disease, but the evaluation and control of the causative agents, should be considered as the initial practice of industrial hygiene, at least in the United States. It should be appreciated that many of the early practitioners of industrial hygiene were physicians who, like Alice Hamilton, were interested not only in the diagnosis and treatment of illnesses in industrial workers, but also in hazard control to prevent further cases. These physicians working with engineers and other scientists interested in public health and environmental hazards took the knowledge and insights developed over several millennia from Hippocrates to Ramazzini, Thackrah and McCready, and began the process of deliberately changing the work environment with the goal of preventing occupational diseases. What or who then can be designated as representing the origin of the profession? Is there any one person who deserves the title Founder of Industrial Hygiene? Certainly, if the name of one individual is sought, that of Alice Hamilton shines like a beacon. But think back to more than 10,000 years ago at the end of the Stone Age, when occupations began to form with the grinding of stone, horn, bone, and ivory tools with sandstone, and with pottery making and linen weaving. Envision a thoughtful worker who suffered from the musculoskeletal problems associated with grinding, made adjustments to his working conditions, and passed the ideas on to co-workers. Recognizing ergonomic problems and solving them would qualify him as an early industrial hygiene practitioner. If that scenario can be imagined, perhaps it is also conceivable that tens of thousands of years ago there was a huntress who recognized the signs and symptoms of anthrax in the bison her group had killed and who made the connection between earlier kills of diseased animals and sickness in members of her tribe. If she then warned her companions of the hazard involved and sought to avoid diseased animals, would she not qualify as one of the founders of the industrial hygiene profession?

If the basic philosophy of the profession is understood, protection of the health and well-being of workers and the public through anticipation, recognition, evaluation, and control of hazards arising in or from the workplace, then the rich tapestry that chronicles the history of industrial hygiene can be imagined. It began when one person recognized a work hazard and took steps not only for self protection, but also for protection of fellow workers. This is the origin and essence of the profession of industrial hygiene.

Historical Events in Industrial Hygiene

1,000,000 BC - Australopithecus used stones as tools and weapons. Flint snappers suffered cuts and eye injuries; bison hunters contracted anthrax.

10,000 BC - Neolithic man began food producing economy and the urban revolution in Mesopotamia. At end of Stone Age, grinding of stone, horn, bone, and ivory tools with sandstone; pottery making, linen weaving. Beginning of the history of occupations.

5000 BC - Copper and Bronze Age - metal workers released from food production. Metallurgy- the first specialized craft.

370 BC - Hippocrates dealt with the health of citizens, not workers, but did identify lead poisoning in miners and metallurgists. 50 AD Plinius Secundus (Pliny the Elder) identified use of animal bladders intended to prevent inhalation of dust and lead fume.

200 AD - Galen visited a copper mine, but his discussions on public health did not include workers’ disease.

Middle Ages No documented contributions to the study of occupational diseases.

1473- Ellenborg recognized that the vapours of some metals were dangerous and described the symptoms of industrial poisoning from lead and mercury with suggested preventive measures.

1500 - In De Re Metallica (1556), Georgius Agricola described every facet of mining, smelting, and refining, noting prevalent diseases and accidents, and means of prevention including the need for ventilation. Paracelsus (1567) described respiratory diseases among miners with an excellent description of mercury poisoning. Remembered as the father of toxicology. All substances are poisons . . . the right dose differentiates a poison and a remedy.

1665 - Workday for mercury miners at Idria shortened.

1700 - Bernardino Ramazzini, Father of occupational medicine, published De MorbisArtificumDiatriba, (Diseases of Workers) and examined occupational diseases and cautions. He introduced the question, Of what trade are you?

1775 - Percival Pott described occupational cancer among English chimney sweeps, identifying soot and the lack of hygiene measures as a cause of scrotal cancer. The result was the Chimney-Sweeps Act of 1788.

1830 - Charles Thackrah authored the first book on occupational diseases to be published in England. His views on disease and prevention helped stimulate factory and health legislation. Medical inspection and compensation were established in 1897.

1900s - Dr. Alice Hamilton investigated many dangerous occupations and had tremendous influence on early regulation of occupational hazards in the United States. In 1919 she became the first woman faculty member at Harvard University and wrote exploring the Dangerous Trad.

1902-1911 - Federal and then state (Washington) legislation covering workers’ compensation. By 1948 all states covered occupational diseases. First survey in the United States of the extent of occupational disease conducted by the Illinois Occupational Disease Commission. Massachusetts appointed health inspectors to evaluate dangers of occupations.

1910 - First national conference on industrial diseases in the United States.

1912 - U.S. Congress levied prohibitive tax on the use of white phosphorus in making matches.

1913 - National Safety Council organized. New York and Ohio established first state industrial hygiene agencies.

1914 - USPHS organized a Division of Industrial Hygiene and Sanitation. American Public Health Association organized section on industrial hygiene.

1916 - American Association of Industrial Physicians and Surgeons formed. American Medical Association held first symposium on industrial hygiene and medicine. 1922 Harvard established industrial hygiene degree program.

1928-1932 - Bureau of Mines conducted toxicological research on solvents, vapours, and gases.

1936 - Walsh-Healy Act required companies supplying goods to government to maintain safe and healthful workplaces.

1938 - National (later American) Conference of Governmental Industrial Hygienists formed.

1939 - American Industrial Hygiene Association organized. American Standards Association and ACGIH prepared first list (maximum allowable concentrations) of standards for chemical exposures in industry.

1941-1945 - Expanded industrial hygiene programs in states. 1941 Bureau of Mines authorized to inspect mines.

1952 - Prof M.N.Rao was the first Indian from Andhra Pradesh who was deputed to International Labour Organisation (ILO) convention to present the Occupational Health status in India.

1960 - American Board of Industrial Hygiene organized by AIHA and ACGIH.

1966 - Metal and Non-metallic Mine Safety Act.

1968 - Professional Code of Ethics drafted by AAIH. Code adopted by all four industrial hygiene associations by 1981.

1969 - Coal Mine Health and Safety Act. 1970 Occupational Safety and Health Act.

1977 - Federal Mine Safety and Health Act. 1992-present Efforts to significantly amend OSH Act. 1995 Revised Professional Code of Ethics adopted by all four industrial hygiene associations.

Fig. 1.2 A Portrait of Paracelsus (1567) Who is Remembered as the Father of Toxicology

Fig. 1.3 Dr. Alice Hamilton

Science of industrial hygiene flourished in many countries, the United States provided the fertile ground for the development of the profession as it exists today. As the industrial revolution, propelled by the Civil War, progressed in the nineteenth century, individuals began to observe serious health and safety problems (recognition). They also considered the effects on workers (evaluation) and made changes in the work environment (control) to lessen the effects observed. Although these efforts may have resulted in improved worker health and safety, their application was not recognized as the practice of industrial hygiene until the early 1900s. In addition to a chronological listing, these activities also illustrate the concepts of the profession— i.e., recognition, evaluation, and control— which may help to better describe today’s practice of industrial hygiene.

1.2 Definitions

Health: Health may be defined as

1. The state of being free from illness or injury

2. A person's mental or physical condition

3. As defined by World Health Organization (WHO), it is a State of complete physical, mental, and social wellbeing, and not merely the absence of disease or infirmity

4. The ability to adapt and self-manage in the face of social, physical, and emotional challenges

5. Absence of disease

6. The condition of being sound in body, mind or sprit especially freedom from physical disease or pain

1.2.1 Health

1.2.1.1 The Determinants of Health

Introduction: Many factors combine together to affect the health of individuals and communities. Whether people are healthy or not, is determined by their circumstances and environment. To a large extent, factors such as where we live, the state of our environment, genetics, our income and education level, and our relationships with friends and family all have considerable impacts on health, whereas the more commonly considered factors such as access and use of health care services often have less of an impact.

The determinants of health include:

•The social and economic environment

•The physical environment

•The person’s individual characteristics and behaviours

The contexts of people’s lives determine their health, and so blaming individuals for having poor health or crediting them for good health is inappropriate. Individuals are unlikely to be able to directly control many of the determinants of health. These determinants or things that make people healthy or not include the above factors, and many others

•Income and social status - higher income and social status are linked to better health. The greater the gap between the richest and poorest people, the greater the differences in health

•Education - low education levels are linked with poor health, more stress and lower self-confidence

•Physical environment - safe water and clean air, healthy workplaces, safe houses, communities and roads all contribute to good health. Employment and working conditions - people in employment are healthier, particularly those who have more control over their working conditions

•Social support networks - greater support from families, friends and communities is linked to better health. Culture - customs and traditions, and the beliefs of the family and community all affect health

•Genetics - inheritance plays a part in determining lifespan, healthiness and the likelihood of developing certain illnesses. Personal behaviour and coping skills - balanced eating, keeping active, smoking, drinking, and how we deal with life’s stresses and challenges all affect health

•Health services - access and use of services that prevent and treat disease influences health

•Gender - Men and women suffer from different types of diseases at different ages

Fig. 1.4 The determinants of health

1.2.1.2 The spectrum of health and illness

To describe health as the absence of disease is inadequate and unsatisfying. We have defined diseases for the last four hundred years or so according to the presence of certain lesions, or the presence of abnormal readings measured by instruments of investigation. Illness is a related, but different, term from disease. It is used mainly to refer to the experience of being unwell, incorporating our concept of disease, but actually describing the subjective experience of a person. Only a person can tell you they feel nauseated, or that they have pain. Instruments won’t reveal those phenomena.

Fig. 1.5 Spectrum of health and illness

1.2.1.3 Factors Effecting Health

1. Social and economic factors

2. Environmental factors (Health)

3. Personal factors

4. Hereditary factors

1. Social and Economic Factors: It depends upon

•Income

•Employment and working conditions

•Food security

•Environment and housing

•Early childhood development

•Education and literacy

2. Environmental factors (Health): Environmental health risks are factors outside of the body that can affect a person’s wellbeing and influence their behaviour. Examples include the quality of a person’s air, food and water supply or their exposure to hazardous materials. Preventing or reducing the risk of illness, injury or disease in the community is essential to good environmental health.

Examples of environmental health risks

Environmental health covers many different factors in a person’s surroundings. These can include:

•Air pollution - for example, smog, wood smoke and mould.

•Water quality - for example, grey water, tank water, fluoridation and drought.

•Food quality - for example, contamination and nutrition.

•Chemicals - for example, pesticides, farm chemicals, arsenic and CCA treated timber.

•Metals - for example, exposure to lead, mercury and cadmium.

•Diseases from animals and insects (vector borne) - for example, dengue fever, hendra virus, lyssavirus, Ross River fever and malaria.

•Infectious diseases - for example, viral infections like swine flu.

3. Personal factors: Personal factors are those which relate to a particular individual and can have an effect on how they act and behave. This obviously has repercussions for overall health and safety as factors such as their attitude, motivation and ability to do the task will all influence the way they work and how. Whilst some personal factors may be ingrained into the person's character and be extremely difficult or even impossible to change, there will be others which can be influenced.

4. Hereditary Factors: You might already have a general understanding about heredity that - it is carried from parents to their children and will affect the health and physical characteristics of children. But do you want to know more about what heredity is and how it affects the health and other physical and mental characteristics? Then we answer in detail to your questions.

We know that genes play an important role in determining our physical characteristics. But to know how genes work, let’s get into some biology facts. Cells in human body contain a substance called deoxyribonucleic acid (DNA). DNA is wrapped together to form structures called chromosomes.

1.2.2 Hygiene

Industrial hygiene has been defined as that science and art devoted to the anticipation, recognition, evolution, and control of those environmental factors or stresses arising in or from the workplace, which may cause sickness, impaired health and wellbeing, or significant discomfort among workers or among citizens of the community.

1.2.3 Hazard

A hazard is a situation that poses a level of threat to life, health, property, or environment. Most hazards are dormant or potential, with only a theoretical risk of harm; however, once a hazard becomes active, it can create an emergency situation. A hazardous situation that has come to pass is called an incident. Hazard and possibility interact together to create risk.

Classification of Hazard

Classification of hazard

1. Physical hazard

2. Chemical hazard

3. Biological hazard

4. Ergonomic hazard

5. Psychological hazard

1. Physical hazard: A physical hazard is a type of occupational hazard that involves environmental hazards that can cause harm with or without contact. Physical hazards include ergonomic hazards, radiation, heat and cold stress, vibration hazards, and noise hazards.

Engineering control are often used to mitigate physical hazards.

Physical hazards are a common source of injuries in many industries. They are perhaps unavoidable in certain industries, such as construction and mining, but over time people have developed safety methods and procedures to manage the risks of physical danger in the workplace. These include excessive levels of ionizing and no ionizing electromagnetic radiation, noise, vibration, illumination, and temperature

In occupations where there is exposure to ionizing radiation, time, distance, and shielding are important tools in ensuring worker safety. Danger from radiation increases with the amount of time one is exposed to it; hence, the shorter the time of exposure the smaller the radiation danger.

Distance also is a valuable tool in controlling exposure to both ionizing and non-ionizing radiation. Radiation levels from some sources can be estimated by comparing the squares of the distances between the worker and the source. For example, at a reference point of 10 feet from a source, the radiation is 1/100 of the intensity at 1 foot from the source.

Shielding also is a way to protect against radiation. The greater the protective mass between a radioactive source and the worker, the lower the radiation exposure.

No ionizing radiation also is dealt with