'Develop healthy public policy' was initially classed as a subclass of a 'promote better health' function. In consultations it was pointed out that this function, method or strategy was cross-cutting, applying to all primary functions, and should not be singled out as belonging only to one function, or as separate to all other functions. 'Policy development' was thus classed as a 'method' of intervention so that it can be applied to any or all of the public health functions in an additional dimension. 56 AIHW 2004b. 57 The post-SARS Canadian view is that: 'Among the functions of public health are health protection (e.g. food and water safety, basic sanitation), disease and injury prevention (including vaccinations and outbreak management), population health assessment; disease and risk factor surveillance; and health promotion. The public health system tends to operate in the background unless there is an unexpected outbreak of disease such as SARS or failure of health protection as occurred with water contamination... Monitor health Monitor and analyse levels of health and its determinants in populations to identify and predict trends and emerging issues ('Assess health inequalities' would be a further subclass of this).