In 1811 the population of London passed 1 million, the first Western city since Imperial Rome to do so. Public health and urban planning as we know them were formed in this crucible — what The Times in 1848 called the great evil of the cities of industrial England: overcrowding, destitution, crime, high urban mortality and terrifying epidemics of infectious disease.
Edwin Chadwick authored the Sanitary Report of 1842 and was the architect of the reformed Poor Laws and the first Public Health Act. The Poor Law provided the first technical definitions of overcrowding — less than 300 cubic feet for paupers and 500 cubic feet for the sick but for Chadwick filth and sewer gas were the causes of the torpor and immorality of the poor. The sanitarians invented civic hygiene and can lay claim to contributing to the great declines in mortality throughout the nineteenth and twentieth centuries.
By 1901, the population of London had reached 4.5 million — roughly the size of Greater Sydney today. Whilst mortality had declined dramatically, the plight of the urban poor was bleak, overcrowding was at crisis point and the air was thick with sulphur and soot.
The flight of the middle classes from central London began during the cholera epidemics in the 1860s, and was given greater momentum by the visions of Ebenezer Howard in his booklet Garden Cities of Tomorrow. Howard’s influence on city planning, particularly in the United States, was large. The electrification of trams and trains provided cheap and rapid transport to the new suburbs, where clean air and sunshine were the advertised benefits. These benefits extended to those left behind in the inner cities when the use of coal as a domestic and industrial fuel declined from the 1950s onwards.
In Sydney, life expectancy continues to increase and many of the major causes of death and disability — cardiovascular disease, cancer and injury are in decline. Sydney is a vibrant international city which offers material and educational resources, employment, social support, physical security and access to medical care — all important for health. What are the health problems which over the next 30 years could be averted by prudent urban planning?
The current worldwide epidemic of obesity can be viewed as the culmination of a 300 year march of the human species from population wide under-nutrition to over-nutrition. Obesity is no more a moral failure than was poverty in the time of Chadwick, but a direct consequence of the diminishing opportunities for physical activity, and of our diet. The bill is beginning to arrive. Obesity is strongly linked to diabetes and heart, stroke and other vascular diseases. In Sydney we are already seeing unprecedented increases in Type 2 or adult onset diabetes in children. A recent assessment of future health care costs in Australia predicted that prevalence and costs of diabetes will increase dramatically over the next 25 years. Modest increases in physical activity and reductions in caloric intake can avert this looming medical disaster.
Suburbs which are walkable have been shown to have lower rates of obesity than those which are not. High-walkability neighbourhoods have concentrations of non-residential land uses such as restaurants, shops and other small retail businesses along the main transport corridors and a mostly grid-like street pattern, with short block lengths and few cul-de-sacs. Developments such as the Rouse Hill town centre embody these principles, but over 70 per cent of the population growth projected in Sydney will occur in existing suburbs. Improvements in walkability in these existing areas must to be promoted as a condition of future development.
How much we earn, our occupation and level of education, our housing and where we live can all influence our health. Urban planning and housing policies can create and perpetuate disadvantage by concentrating it unduly in certain areas, by poor urban design and by failing to create or sustain economic and social diversity. Tony Vinson has observed that once established, the effects of extreme local cumulative disadvantage are often stubbornly resistant to state or national social initiatives.
Increasing urban residential densities will be an inevitable part of Sydney’s future. There will be more people living closer together, more living near transport corridors, and more exposed to noise and air pollution. Noise has been linked to sleep disturbance, high blood pressure and impaired learning in children, and is the commonest source of complaints to police, and local and state government agencies. Australia has been slow to embrace some of the more stringent noise abatement measures which are common in Europe: the design of tyres and road surfaces, building materials and noise ratings for multiple occupancy dwellings. Air pollution research increasingly points to greater risks in those living close to busy road corridors.
The health of future populations is inextricably linked to the sustainability of our current levels of energy and water usage, and production of greenhouse gases. And yet public health officials schooled in the pieties of the sanitary era bring an instinctive conservatism to decision making about for example, the recycling of sewage into the potable supply. However, the predicted decline in the average annual rainfall in Sydney will propel this debate forward. This week the construction of a large water recycling plant in Western Sydney has been announced. There is every chance that these arguments about the technical merits and necessity of proffered solutions will be as lively and important for the sustainability of Sydney as that between Chadwick and Joseph Bazelgette, London’s chief engineer, about the form and location of London’s sewers.
What can be done? Currently the evidence base for confident policy formulation is weak. However, the most recent metropolitan plans in Perth, Brisbane and Sydney have embraced liveability as a design principle and wellbeing of the population as a desired outcome. They also address issues of housing affordability, safety, transport and access to employment, all of which have discernible impacts on human health. To fully elaborate these planning principles we will need as a minimum:
– A renewal of the professional and administrative linkages between urban planning and public health, through training, collaborative research and joint policy development. This needs to occur in State Health and Planning agencies, but in particular in local government, which has a pivotal role in the development and expression of urban form. Their regulatory roles in relation to zoning, residential density, transport and land use planning and the utilisation of parks and open space can have major impacts on levels of physical activity and social connectivity in the community.
– The codification where possible of health standards. Examples might include design and setback criteria for multi-storey dwellings near major transport corridors which minimise exposure to noise and air pollutants.
– The adoption of well chosen benchmarks of across-government performance. Reductions in average weekly travel time, for example, has the potential to be a proxy measure of both the success of city planning and of a number of risk factors affecting physical and mental health.
– An increasing focus on the food environment. Research on just how the built environment may affect eating behaviour is in its infancy, but issues such as the density of fast food outlets in a neighbourhood and their proximity to schools are potentially within the purview of local planners.
– Broadening the scope of Environmental Impact Assessments of major developments to include explicit and properly specified considerations of health impacts.
The economist and Nobel laureate Robert Fogel in his book The Escape from Hunger and Premature Mortality 1750-2100 has charted the remarkable extent to which humans have literally re-shaped themselves in relation to the privations of the environments in which they have lived. The decisions that are being now about urban planning and the shape of our city are doing nothing less than defining the conditions of our existence, and that includes our health, for decades to come.