In this episode, Medlock Holmes turns his gaze upward - to the currents of air that carry both life-sustaining oxygen and harmful pollutants.

Air pollution modelling allows public health professionals to predict how contaminants disperse, accumulate, and affect populations. Holmes introduces the core components of modelling:

* Emission sources (traffic, ind…

In this episode, Medlock Holmes steps into a realm that cannot be seen, touched, or smelled - yet profoundly influences human health: radiation.

We begin with the electromagnetic spectrum, distinguishing between ionising radiation (X-rays, gamma rays, radioactive particles) and non-ionising radiation (ultraviolet, infrared, radiofrequency, and extremely …

In this episode, Medlock Holmes turns his attention to the external forces that surround - and sustain - human life. Environmental health examines how physical, chemical, and biological factors in our surroundings influence disease patterns and wellbeing.

Holmes traces the historical arc of environmental thinking in public health - from early sanitation …

In this episode, Medlock Holmes confronts one of the most persistent challenges in public health: the gap between what we know works and what is actually delivered.

Scientific discovery alone does not save lives. Vaccines must reach arms. Guidelines must change practice. Policies must function at the frontline. Implementation science studies the how - th…

In this episode, Medlock Holmes moves from interventions and incentives to institutions. Public health does not operate in isolation; it functions within governance structures and management systems that determine priorities, accountability, and performance.

Holmes begins by distinguishing governance from management:

* Governance defines direction, oversigh…

In this episode, Medlock Holmes steps into the subtle terrain between rational theory and real human behaviour.

Traditional economics assumes that individuals make rational decisions to maximise benefit. Behavioural economics challenges this assumption. People are influenced by cognitive biases, heuristics, framing, defaults, loss aversion, and social no…

In this episode, Medlock Holmes steps into the chamber of decision-making where evidence meets constraint. Public health operates under limited budgets, competing priorities, and ethical trade-offs. Economic appraisal provides the structured tools to guide those choices.

Holmes introduces the core approaches to economic evaluation:

* Cost-minimisation analy…

In this episode, Medlock Holmes confronts a reality of modern public health: most meaningful interventions are not single actions, but interconnected systems of change.

A vaccination is simple. A health system reform is not. Reducing obesity, improving mental health, tackling health inequalities - these require interventions with multiple components, int…

In this episode, Medlock Holmes moves from measuring populations to mobilising them. Health promotion is not simply about delivering information - it is about enabling people to improve and sustain their wellbeing.

Holmes begins by revisiting the foundational principles of modern health promotion, including the shift from disease treatment to empowerment…

In this episode, Medlock Holmes turns his attention to the architecture of populations. Demography is the study of population size, structure, and change - and it underpins nearly every public health decision.

Holmes begins with the core components of demographic change:

* Fertility

* Mortality

* Migration

We explore key demographic measures: crude birth and death…