Over the broad sweep of history, changes in environment, in human ecology and in contacts between civilisations have largely determined the tides of infectious diseases and the changing nutritional fortunes of populations. For several thousand years, disease and death have been dominated by the biblical Four Horsemen – war, conquest, famine and pestilence. Within the European region over recent centuries, the gradual ‘domestication’ of epidemic infections and the attainment of famine-free food supplies laid the foundations for a healthier living environment. This broadly coincided with the onset of industrialisation. Two thousand years ago the fevered mind of St John the Divine, with his vivid vision of the horsemen as agents of divine wrath, could not have foreseen human society's eventual industrialisation and its many health consequences. Is industrialisation the Fifth Horseman? (Or, with some poetic licence, is it a variant of the First Horseman, Conquest–the conquest of nature?)

There have been great material benefits and social advances associated with industrialisation, beginning in England in the late eighteenth century. Via the accrual of wealth, the processes of social modernisation and the development of specific public health and medical interventions, the industrial era has contributed enormously to the gains in life expectancy in economically developed countries over the past two centuries. However, industrialisation has also caused much environmental blight and ecological damage and, consequently, has created various risks to health.