Today’s concept of occupational health has greatly changed from yesterday’s concept of industrial health and now it is fast changing to environmental health because of greater awareness of the ecological problems arising from rapid industrialisation, the use of complex processes and hazardous chemicals in industries, and urbanisation.

The joint International Labour Organisation/World Health Organisation Committee on Occupational Health, in the course of its first session held in 1950 stated: "Occupational health should aim at the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations; the prevention among workers of departures from health caused by their working conditions; the protection of workers in their employment from risks resulting from factors adverse to health; the placing and maintenance of the worker in an occupational environment adapted to his physiological and psychological equipment, and, to summarise, the adaptation of work to man and of each man to his job."

HISTORY:
Global Perspective:
The first book on occupational medicine, De Morbis Artificum Diatriba (meaning “Diseases of Workmen”), was published in 1700 in Italy by the “father of occupational medicine” Bernardino Ramazzini (1633-1714). It contained accurate descriptions of occupational diseases linked to various types of jobs.

Then came the Industrial Revolution in England (1760-1830), which gave pace to the occupational health movement. Dr. Alice Hamilton played a great role in the development of industrial hygiene in America during the early part of the 20th century. The Office of Industrial Hygiene and Sanitation was established in 1914 in the USA. In 1919, the ILO came into being in Geneva, Switzerland, with a Department of Occupational Safety, Health and Welfare. Subsequently, the WHO in Geneva, Switzerland, also set up a Department of Occupational Medicine.

Indian Perspective:
The first Factories Act was passed in 1881 in British India. The act was amended in 1891, 1911, 1923, 1934 and 1948 to bring the legislation in line with that of the British Factory Act. The Bhopal Gas tragedy (1984) was a turning point towards legislation pertaining to occupational health and safety in India. The Factories Act was amended (1987) and stipulated the qualifications/strength of occupational health staff in hazardous industries. At present 29 diseases have been included as “notifiable” occupational diseases under this Act.

There is a dearth of qualified occupational health physicians in our country. Awareness about occupational health is at a low level even in the organised sector. Most affected is the unorganised and small-scale sector. The Indian Association of Occupational Health is the leading NGO in the field of occupational health in India.

THE CAUSES OF OCCUPATIONAL DISEASES:
There are various modes of development of occupational diseases. Some are only occupational in origin, such as silicosis or asbestosis, which are caused by exposure to silica dust or asbestos fibres, respectively. In some diseases the occupation is one of the causal factors whereas in others the occupation is a contributing factor (for example: chronic bronchitis). There are also cases in which an individual’s occupation may aggravate a pre-existing condition (as in bronchial asthma).

An individual may be exposed to five types of hazards, depending upon his/her occupation:

a) Physical hazards: Heat, cold, light, noise, vibration, ultraviolet radiation and ionising radiation are all known to give rise to problems if the individual is exposed to levels beyond acceptable limits without protective measures.

b) Chemical hazards: Toxic, corrosive, allergenic and carcinogenic chemicals act by local action, inhalation and ingestion on exposure to concentrations beyond the threshold limit value (TLV).

c) Biological hazards: Workers may be exposed to infectious and parasitic agents at the workplace. Persons working with animal products and agricultural workers are likely to be exposed to biological hazards.

d) Mechanical hazards: The mechanical hazards in industry centre round machinery, protruding and moving parts and the like. About 10 per cent of industrial accidents are due to mechanical causes.

e) Psychosocial hazards: These arise from the workers’ failure to adapt to an alien psychosocial environment. Frustration, lack of job satisfaction, insecurity, poor human relationships and emotional tension are some of the psychosocial factors that may undermine both the physical and mental health of workers.

In addition to the above, new technologies like video display units and computers also bring with them new hazards and problems such as repetitive strain injury or musculoskeletal disorders if not used properly. Ergonomics plays an important role in the prevention of such diseases.

THE ROLE OF OCCUPATIONAL HEALTH SERVICES (OHS):
The scope of occupational health services includes preventing occupational hazards at work, protecting workers against hazards at work, help in adapting work and the work environment to the capabilities of the worker, promoting the physical, mental and social well-being of workers, and cure and rehabilitation of accidental occupational injuries.

The main objectives of the OHS may include the following:

	To provide medical treatment and support in case of an emergency illness or accident.
	To monitor, manage and modify any adverse health effects which may occur at the
	workplace.
	To promote good health at the workplace.
	To plan and execute health education and awareness programmes for employees.
The major activities at an Occupational Health Centre may include:
	Medical surveillance through measures such as periodic medical check-ups.
	Pre-employment medical check-ups.
	Medical treatment for illnesses and accidents.
	Conducting health education programmes.
	Providing first aid and other related training to the employees.
	Promoting health awareness and wellness measures among em-ployees.

Occupational Health should get the importance and attention it deserves. OHS should adopt proactive strategies for medical surveillance of workers in the industry. These need to extend beyond statutory provisions to promote the working capacity and health of the employees. The OHS department should regularly undertake health promotion campaigns. It can initiate special programmes or monitoring for employees suffering from chronic diseases like diabetes, hypertension, etc., to prevent complications and preserve productivity of employees.

STATUS OF OCCUPATIONAL HEALTH IN INDIA:
India has a population of over 1 billion, approximately 33 per cent of which is working class. Out of more than 2 lakh registered factories around 5,000 are classified as chemical industries with more than 5 lakh employees.

Apart from large and medium industries, small industries play an important role in the economy of the nation. The small-scale sector contributes 45 per cent of the country’s total production.

The Ministry of Labour, Government of India, is responsible for matters relating to the safety, health and welfare of workers in the country and it also administers the relevant statutes/legislation, and the occupational health care system. A large portion of the working population is employed in the unorganized sector like agriculture and allied fields, whose occupational health needs have not been addressed so far. Hence, promoting the occupational health of the country’s large workforce is a gigantic task.

Given the country’s vast human resources potential, the Government of India has accorded a prominent position to occupational safety and health.

The Directorate General, Factory Advice and Labour Institutes, Mumbai, under the Ministry of Labour, Government of India, provides statutory regulations, assistance to the enforcing agencies, training and education in thefield of occupational health and safety, and conducts occupational health studies to assess the prevalence of occupational health disorders and occupational diseases. The State-level health care of workers is ensured by medical inspection services of the State Factory Inspectorates and medical examination by the certifying surgeons.

In the industrial population, health care is usually provided by the management through the Employees State Insurance Scheme. As per the amended Factories Act, provision of an Occupational Health Centre is mandatory in factories carrying out hazardous processes. Many progressive industries have established preventive occupational health services to look after their workers’ occupational health needs.

CHALLENGES IN THE 21^st CENTURY:
With new and sophisticated technology and newer work methods, systems and processes, the occupational health of the worker has come under severe stress. Outsourcing of manufacturing activities from developed to developing countries has added new dimensions on the health front. Globalisation of manufacturing practices is resulting in cross-border transition of the workforce from one country to another causing tremendous stress in terms of cultural conflicts, new health and environmental hazards and other psychosocial problems. In addition, as more hazardous industries are set up in the country, the environmental pollution increases as do accidents, occupational diseases and catastrophic risks.

The approach towards health is now changing from cure to prevention. The engineering approach is to ensure safer processes, an integrated systems approach and better occupational environment, whereas the medical approach emphasizes identifying the health risks and their prevention. Ergonomic interventional techniques are receiving due importance in the prevention of occupational diseases.

There is an increasing use of Information Technology for mass awareness and education. The Government as well as enterprises are formulating comprehensive health, safety and environment policies. While enterprises are trying to integrate health and safety management systems with quality assurance systems, the progressive governments are aiming at the integration of occupational health with primary health care in the country. We need to develop a national network on occupational health in our country.
Looking at the trend of globalisation, we need technical cooperation and collaboration in OHS matters at the global level.

CONCLUSION:
In this integrated and interdependent global market environment, safety, health and environmental issues are going to be transnational, and the challenges in the field of occupational health are going to be enormous. Therefore, we as a nation, i.e. the Government, employers and employees have to wage a total war on occupational diseases through various multidisciplinary interventions and proactive strategies to promote occupational health and improve the quality of work-life of our working population.