Occupational diseases caused by physical overload

Disorders of the visual apparatus

Fatigue of the visual organ is provoked by close-range work, frequent changes in brightness levels, the need to examine small or moving details, and constant shifting of gaze. As a result, light sensitivity decreases, the iris muscles and accommodation apparatus become exhausted, which is often accompanied by pronounced pain.

The main forms of occupational eye pathology include:

• Asthenopia. Accompanied by blurred vision, aching in the eye sockets, general fatigue, and headache. With prolonged exposure to the factor, especially in young workers, it provokes accommodation spasm, leading to the development of transient false myopia.
• Occupational myopia. A persistent disorder that forms under significant visual loads. It is characterized by manifesting in adulthood and not exceeding 3.0 diopters.
• Occupational nystagmus. A specific disease of miners and pitmen arising from working in poor lighting. It manifests as rapid rhythmic eye movements, tremors of the head and eyelids, and persistent headaches.

Disturbances in dentists are singled out separately, as the incorrect spectrum of lamps distorts color rendering. This leads to difficulties in recognizing small objects, rapid fatigue, and pain.

Overstrain of the respiratory system and vocal apparatus

Teachers, singers, artists, glassblowers, and wind instrument musicians are subject to increased loads on these systems. Prolonged forcing of breathing and vocal cords leads to the following diseases:

1. Occupational pulmonary emphysema. An organic lesion of the lung tissue typical of individuals whose profession requires generating high pressure in the airways (glassblowers, musicians).
2. Chronic laryngitis. Typical for people in "voice-intensive" professions. The disease is accompanied by inflammatory processes, the formation of specific "singer's nodes" on the vocal cords, and in advanced cases can lead to paresis of the vocal apparatus.

Labor monotony and its physiological effects

The introduction of assembly lines reduced the share of heavy physical labor, but gave rise to the problem of monotonous labor—performing simple, repetitive elements at a set pace involving limited muscle groups. This induces a state of monotony.

The central nervous system (CNS) exhibits:

• Prolonged visuomotor reaction times;
• Decreased excitability of spinal (direct) and supraspinal (indirect) centers;
• The electroencephalogram (EEG) shows an increase in the proportion of low-frequency alpha rhythm (a sign of CNS depression) and theta rhythm (an indicator of compensatory nervous tension).

Autonomic functions are also depressed: breathing slows down, heart rate drops by 25–30%, and blood pressure decreases (especially systolic). Subjectively, this is perceived as apathy, boredom, and drowsiness. Young workers (under 20 years of age) and individuals from the monotophobia group are most sensitive to monotony.

Comprehensive prevention of overstrain

The main direction in preventing musculoskeletal pathologies and the consequences of overstrain is mechanization of labor-intensive processes.

The following measures are used to optimize working conditions:

• Organizational: shortening the shift to 6 hours, strict adherence to weightlifting standards, introduction of the buffer-stock method (conveyors with accumulators for work at a free pace).
• Ergonomic: improvement of tools (weight reduction, better handles), alternation of sitting and standing postures, workplace gymnastics, and self-massage.
• Sanitary and hygienic: control of the spectrum and level of illumination, introduction of functional music, creation of psychological relief rooms.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Classification of types of monotonous labor (physical and operator components).
• The influence of the degree of responsibility and information complexity on labor intensity.
• Organization of the correct work and rest schedule in conveyor production.
• The influence of working conditions on the visual apparatus of dentists.

Other topics in "Chapter 6. Fundamentals of Occupational Hygiene and Physiology"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.