Occupational Health Hazards and Assessment

Occupational health hazards are the agents and conditions in a workplace that have the potential to harm the health of workers, and assessment is the systematic process of identifying those hazards, judging the risk they pose, and prioritising controls. Together they form the foundation of preventive occupational health practice, because no exposure can be reduced until it has first been recognised and characterised.

Definition

An occupational hazard is any agent or condition arising from work with the potential to cause injury or illness; occupational hazard assessment is the structured identification of such hazards, estimation of the resulting risk, and ranking of control measures to prevent harm.

Scope

This topic covers the main categories of workplace hazard, the logic of hazard identification and risk assessment, and the hierarchy of controls used to reduce exposure. It is a reference and educational account aimed at understanding how working populations are protected; it does not provide instructions for diagnosing or treating any individual worker's condition.

Core questions

• What kinds of hazards arise in workplaces, and how are they classified?
• How is a hazard distinguished from exposure and from risk?
• What steps make up a structured risk assessment?
• How are control measures chosen and prioritised once a risk is identified?

Key concepts

• Physical hazards (noise, vibration, radiation, temperature)
• Chemical hazards (dusts, fumes, solvents, gases)
• Biological hazards (bacteria, viruses, bloodborne pathogens)
• Ergonomic hazards (repetitive motion, manual handling, posture)
• Psychosocial hazards (workload, control, harassment)
• Hazard identification, risk estimation, and risk evaluation
• Hierarchy of controls and the precautionary principle

Mechanisms

Hazard assessment follows the exposure pathway from agent to effect. First a hazard is identified and classified by type; then exposure is characterised by route, dose, and duration; then risk is estimated by combining the likelihood and severity of harm. Because risk scales with exposure, control measures are ranked by how reliably they remove the worker from the hazard, giving the hierarchy of controls that favours eliminating or substituting the hazard, then engineering controls, then administrative measures, and finally personal protective equipment as the least dependable last line.

Clinical relevance

Recognising the categories of occupational hazard helps health professionals connect a worker's illness or injury to its possible source at work and understand where prevention belongs. This topic describes how exposures are assessed and controlled at the population and workplace level; it is educational and is not a basis for individual diagnostic or treatment decisions.

Epidemiology

Occupational exposures account for a meaningful and largely preventable share of the global burden of disease and injury: the Global Burden of Disease analysis for 2016 attributed a substantial number of deaths and disability-adjusted life-years to occupational risk factors such as carcinogens, particulates, ergonomic strain, and noise. These estimates underline why systematic hazard assessment is a core preventive activity.

History

The systematic study of workplace hazards descends from Ramazzini's catalogue of the diseases of tradesmen and from Alice Hamilton's early-twentieth-century investigations of lead and other industrial poisons, which established that specific workplace agents cause specific diseases. Over the twentieth century this developed into formal risk-assessment frameworks and the hierarchy of controls now promoted by occupational health agencies.

Key figures

• Bernardino Ramazzini
• Alice Hamilton
• Barry S. Levy
• Bonnie Rogers

Seminal works

• gbd-occupational-2020
• niosh-hierarchy-2023
• levy-wegman-2017

Frequently asked questions

What is the difference between a hazard and a risk?

A hazard is something with the potential to cause harm, whereas risk is the likelihood that harm will actually occur, given the level and conditions of exposure; assessment turns the identification of hazards into an estimate of risk.

Why is personal protective equipment considered the least preferred control?

Because it depends on the worker wearing and maintaining it correctly and does not remove the hazard itself; the hierarchy of controls prefers eliminating, substituting, or engineering out the hazard before relying on protective equipment.