Australasian Science Magazine

By Peter Mares

Urban public health expert Billie Giles-Corti discusses how a rigorous, evidence-based approach to urban policy and city planning can help bring long-term benefits for physical and mental health and well-being.

PETER MARES
I'm Peter Mares thanks for joining us. On this program we ask the question: can cities make us sick? More specifically, does our urban environment contribute to the chronic illnesses of the 21st century, like diabetes and cardiovascular disease? If so, could we improve public health with better planning and design? For example if a neighbourhood offers pleasant conditions for pedestrians like wide, shady footpaths or sidewalks, and if it has plenty of interesting or useful places close by like parks or shops, does this mean residents walk more and have better physical health? Could it improve mental health, too, because it results in more chance conversations in the street, helping people to build a sense of community and reduce loneliness?

These are some of the many questions at the heart of the work of leading researcher Billie Giles-Corti, who spent almost 20 years examining the effect of built environments on public health. Professor Giles-Corti takes a rigorous empirical approach to her work seeking an evidence-base for urban policy that brings long term benefits for wellbeing. Billie Giles-Corti is Director of the McCaughey VicHealth Centre for Community Wellbeing in the School of Population and Global Health at the University of Melbourne. She's the current recipient of a principal research fellowship from the Australian National Health and Medical Research Council. That's a prestigious and highly competitive award funding a five-year project of significant benefit to health and medical research. Billie Giles-Corti welcome to Up Close.

BILLIE GILES-CORTI
Thanks very much, Peter.

PETER MARES
Now, a link between cities and health became apparent more than 150 years ago when it was realised that crowded, dirty cities and unsanitary conditions were leading to the spread of infectious diseases, didn't it?

BILLIE GILES-CORTI
Yes, I guess planning actually started and so did public health when people were really concerned about infectious diseases in industrialised cities. So the idea there was that we separated land uses and so we avoided people being exposed to environmental toxins from pollution. We also reduced crowding, we brought in minimum lot sizes and we tried to make cities that were healthier for people by avoiding infectious diseases.

PETER MARES
So things like cholera and typhoid that often ripped through urban communities in the 19th century?

BILLIE GILES-CORTI
Yes. It was very common in the UK, in America and of course even in Australia in the cities that were evolving in cities in Australia we had the same sorts of issues. So it was something that was used as a way of separating land uses, making minimum lot sizes, trying to separate people so that we would avoid infectious diseases.

PETER MARES
Just remind us about the story of the physician John Snow and the cholera outbreak in London in the 1850s.

BILLIE GILES-CORTI
Yes, John Snow was very famous because he was a very smart guy. He started to plot where all the patients were coming from that had cholera. He plotted them out and he could see on a map that they were located in certain areas and not in other areas. He worked out that the cholera cases were clustered together and even on opposite sides of the street.
So on one side of the street people didn't have cholera on the other side of the street they did. Then he worked out that they were getting water from a different source. He famously went down to the Broad Street Pump in London in Soho and removed the pump very famously so people couldn't take water from there and they started to see that there was a decline in disease as a result of that. But the interesting thing is that it did take a very long time for what he hypothesised was the cause of the disease and which he showed by taking the pump away. But it took a very long time for that policy to be translated into policy and practice. In fact it's amazing actually still how cholera outbreaks in the developing world, we know the things that we need to do, sanitation, water. Just the other week the World Health Organization had World Toilet Day, four billion people in the world do not have access to toilets, it's shocking.

PETER MARES
So the key there for infectious diseases and obviously an ongoing issue is to make sure people have clean water and make sure that sewage disposal and sanitation happens properly and those two things are divided.

BILLIE GILES-CORTI
That's not a responsibility of individuals, that's a responsibility of the state. People can't fix that for themselves and so it's the way we design cities. We’ve known that for a very long time and that's what I mean. At times it often takes a very long time for research to be translated into policy and practice.

PETER MARES
In the 21st century we have a different type of epidemic emerging particularly in the developed world but not only in the developed world and that is not of infectious diseases like cholera and typhoid but of chronic diseases. Things like diabetes, type 2 diabetes and cardiovascular disease. What's the link between these diseases and the way we build and organise our cities?

BILLIE GILES-CORTI
Well in the 21st century we're suffering from other things. It's more lifestyle related diseases that are making us more inactive. We're eating unhealthier diets and as a result of that we have an emergency really and we're seeing the global impact of obesity is going to be massive and it's having an enormous impact on diabetes and it will have an impact on cardiovascular disease as well.

PETER MARES
Because obesity leads to both those or it is a very big warning sign for both those diseases isn't it?

BILLIE GILES-CORTI
It's a risk factor for those things and the sorts of things that we need to do in terms of avoiding obesity of course are also independent risk factors of those diseases and that's being physically active throughout the course of the day, trying to be as active as we can, reducing sedentary behaviour and eating a healthier diet. City planning has something to play in all of those risk factors and so the way we design cities can affect whether or not we sit a lot because we're sitting in cars in congestion and we're having a long way to go home. It affects whether or not we can walk easily in our neighbourhood and it can also affect whether or not we've got access to food because that's a planning issue.

PETER MARES
As in how close a source of fresh food is to you, that sort of thing?

BILLIE GILES-CORTI
That's right, so whether you've got access to food choices and whether your neighbourhood is zoned in a way that you can easily just go down to have a healthy food choice or whether there's just only fast food available.

PETER MARES
Now is this really a problem of rich industrialised nations like Australia and the United States, or is it a problem more globally?

BILLIE GILES-CORTI
It's a massive global problem. In fact in September 2011 there was a UN high level meeting in New York, which brought together all the countries to look at chronic diseases, the prevention of chronic diseases and how we are going to deal with that on a global level. What that high level meeting concluded is that this is not a problem of the health sector. The health sector clearly has to deal with it. If we don't deal with it our social and economic development will be affected by the fact that we've got the impact on our health systems.

PETER MARES
Because there'll be so many people who can't work because they're unwell for example and we'll have to spend so much of our budgets caring for them in hospitals and all the rest of it.

BILLIE GILES-CORTI
It's the budgets of hospitals, they won't be able to manage because of course treating disease is much more expensive than preventing the problems in the first place. So we've got this massive growth of obesity and disease and so this meeting looked at what are the solutions to this. They realised that although the health sector has to deal with it, it's not a problem of the health sector alone. They will deal with the problem and have to fix people up, but actually what creates the conditions for good health is the decisions that are made by planners, by transportation planners, by people who work in the environment.
All of these other sectors actually create the conditions for good health and that unless they're going to get on board the health sector is going to have to deal with it. But actually it's everyone else that creates the conditions for good health. That's what we need to be doing is actually looking at integrated planning that we bring all these sectors on board to actually look at what they can contribute to the problem. What we can do about housing, what we can do about recreation, what we can do about transport, what we can do about planning. All of these sectors, multiple sectors need to be involved.

PETER MARES
If you're going to do that though if you're going to change the way a city is organised or make an intervention into a suburb to make it a healthier place, then you've got to do that based on evidence. You've got to know that the intervention you're going to make is actually going to achieve the result you want as in getting people more active, getting them out of their cars that sort of thing. So let's look a bit more closely at the links and the sort of research you've done, because it's up to individuals to do this. There's nothing stopping them walking right now.

PETER MARES
In the health sector we talk about making healthy choices easy choices and yes we do need to all make choices about the way we live our lives. But actually the environment can make that easy or difficult. What we argue is that we need passive interventions, interventions that make it so attractive or so easy that the obvious choice is to be active. The obvious choice in many cities now is not to be active it's to go outside, certainly in many developed countries, you don’t even have to go outside your house, you go into your garage, you get in your car. You use your remote control to put up the garage door. You drive down the street, you get to your office, you go into the car park you actually go up the lift to go into your office.
Now that is a very sedentary lifestyle. That is to do with the way we are designing cities and the way we design houses, the way we design communities. The alternative is that you leave your house, you walk down the street, you jump on a tram or you get on a public bus or a train. You go into the office you have another walk when you get there and if your building is designed well you walk up the stairs. You don't even have to go up the lift. But the obvious choice is the easy choice is the healthy choice is what we would argue is what's really required. I think there's a global movement now showing that if we build it people do come. They do change their behaviour and it's possible to have a passive intervention. So small changes across a total population have an enormous impact on health and wellbeing.

PETER MARES
So if you just got a small proportion of the population walking more that's going to save us a lot of money and mean a lot of healthier people?

BILLIE GILES-CORTI
Exactly, so it doesn't require a huge shift in the population to make this worthwhile. The other thing is of course is that when you start to create these environments that are convivial, attractive and walkable, it attracts other people. It's like a magnet. Now people want more of that and some people of course will continue to drive and use the driving as the alternative. But if we facilitate people, make it easy for people, it makes the healthy choice the easy choice.

PETER MARES
I'm Peter Mares and you're listening to Up Close. In this episode we're discussing cities and health. Asking whether the way we build and organise our cities could be making us ill. My guest is leading Australian public health researcher Professor Billie Giles-Corti. Let's discuss the way in which you go about marshalling your evidence, the actual research that you do. Because it must be very hard to separate out what it is about the urban environment that's influencing health from a whole lot of other factors. So someone's educational level or someone's level of income. Because we know that health is often linked, richer, better educated people, tend, on average to be healthier than poorer, less educated people. How do you make sure that what you're observing is the impact of the urban environment and not some other factor?

BILLIE GILES-CORTI
Yes, that's right so we try and do longitudinal studies and try and measure everything. So in the studies that we've devised and other people throughout the world are devising you measure the people. So you measure their individual factors, you measure their social environmental factors. So in the individual factors, it includes all the demographics that you've described, their age, their sex, their work status, their marital status.

PETER MARES
Their income.

BILLIE GILES-CORTI
All of those things, you measure as many of those as you can. You also measure things about people's attitude, because one of the things is that just if I'm predisposed to - I really like walking so I choose a neighbourhood that I'm really keen to walk in because I can.

PETER MARES
Whereas I really like driving so I choose to live in a neighbourhood that's good for my car.

BILLIE GILES-CORTI|
Exactly, so we want to measure all the things that are individual factors that might predispose you to choosing one behaviour over another. We measure the social environment, what do your friends think, what do your family think, do you live in a supportive environment? Then we measure people's perceptions of the environment. So what they think their neighbourhood is like which becomes particularly important when it comes to crime.

PETER MARES
So do you feel safe going walking the streets, that sort of thing?

BILLIE GILES-CORTI
Exactly and then we also measure the built environment objectively. So we use geographic information systems which are spatial maps, which allow us to locate where people live so we ask people for their address. What we do is we attach to their neighbourhood or their address all the attributes of their neighbourhood. So whether they have a park nearby, whether they have shops nearby, how far is it to public transport. How frequent the public transport is, we even now use Google maps and street view to go in and to audit the parks in the neighbourhood to say - because we realise it's not just about the fact that you have a park. Certainly in Australia our research shows it's not just about that you have a piece of green space, it's how it's designed and the quality of that public open space is really important. What we're doing is actually using the technology to allow us to really describe places in which people live.
That is allowing us then to look at independent of all the things that might account for it whether people have changed their job. Particularly relevant in longitudinal studies, whether they've gained a child, whether they've lost a child. One of the things we find actually, amusingly is that one of the things that is important is whether or not you lose or gain a dog.

PETER MARES
Because if you get a dog you walk a lot more?

BILLIE GILES-CORTI
If you lose your dog you walk a lot less. It actually has a big impact on people's behaviour. So we've put all these things into our models to try and look at the independent impact of the environment.

PETER MARES
Right and when you say it's a longitudinal study of course that means you then watch people over time, so you can see if their environment changes does their behaviour change. That's the idea?

BILLIE GILES-CORTI
Yes, what we've been putting together is like natural experiments.

PETER MARES
What do you mean by a natural experiment?

BILLIE GILES-CORTI
Well what we've been doing in Western Australia for example is we've been monitoring the state government policies. So the state government brought in the liveable neighbourhood policy and we wanted to monitor over time what impact that had on people. Now the gold standard when you're doing a study like this is you do a randomised controlled trial. Now unfortunately people are not that cooperative. We want you to go and live in that house and you've got to pay for it. They don't want to do that.

PETER MARES
You can't really just tell people you go and live here for 10 years and then we'll see how you've done.

BILLIE GILES-CORTI
That's right, yes and you've got to pay for it and we're going to tell you which house you'll live in. They don't want to do that, very uncooperative. So what we do is we look at people who have moved into some neighbourhoods which have been designed according to these guidelines and other people who have moved into other neighbourhoods. We've monitored over time what would happen. That's a longitudinal, natural experiment and we've got a similar study that we're doing in London looking at the impact of the London legacy on the athlete's village which is being converted into social and affordable housing. We're going to monitor over time what impact that has on the people who move in there. That's considered like not the gold standard but a very well designed study to answer this question. So it's - it tries to tease out self-selection factors. Do I choose a neighbourhood that matches the behaviour that I want to do?

PETER MARES
Like a neighbourhood that's good for walking because I like walking.

BILLIE GILES-CORTI
Walking or does the neighbourhood itself, if I'm predisposed to drive it's so good that I can't resist it and I still, I then walk. That would be the optimal situation that we want to make this such a convivial, attractive environment. Who wants to drive in York because you've got great public transport and it's very walkable. So I guess that's the sort of thing that we're trying to monitor.

PETER MARES
You've been working as you said in Western Australia in the city of Perth, the capital of Western Australia a city of about 1.7 million people on Australia's west coast. What is the evidence showing so far from Perth? How big an impact does the environment make? If it's a more pedestrian friendly environment do people indeed walk more?

BILLIE GILES-CORTI
Let me just contextualise Perth for you. Perth is a city of almost 2 million people. It's very car oriented. It competes with the US and LA for how much driving people do. So it's a very low density city. What the government has been trying to do under the sustainability strategy is put in place a policy that will try to rectify that. It's not easy, it's a big ship that needs to be turned around and that's what they're trying to do. What we've found is that the effects are relatively modest but over a population they make a big difference. What we've managed to do is to look at well what happens when people gain access to shops and services? So for every destination that they gain, so the newsagent, the post box which is almost old fashioned these days, the delicatessen.

PETER MARES
Gain access meaning within an easy walk or a relatively easy walking distance like a mile in the American term or one and a half kilometres.

BILLIE GILES-CORTI
A mile or 1.6ks, yes that's right. So for everyone that they gain, so they move from one neighbourhood to the next and they gained a destination they did an extra six minutes of walking. Now you think well that's not very much, but if you live in an area that's rich with lots of little destinations, it means that for everyone that's there there's more things to do and you are more likely to walk.

PETER MARES
Six minutes might not sound like a lot but if people walk half an hour a day that's actually a significant contribution to their health, isn't it?

BILLIE GILES-CORTI
Absolutely, yes that's right. So if we could have lots of little destinations nearby and people do that on a daily basis, walk to those shops and services, we would have an important impact on people's health and wellbeing across a population.

PETER MARES
Now let's talk a bit more about walking, because walking does seem to be really essential to the broader public health strategy. It's an easy thing for people to do generally. But there are different types of walking aren't there. There's the walking I do or the running I do when I'm running to catch the bus to get to work in the morning because I'm late. But there's the walking I do when my wife and I take a stroll in the park and talk about what's happened during the day. They're two different sorts of walking, aren't they?

BILLIE GILES-CORTI
Yes one is like utilitarian, people tend to walk a little bit more intensively than that. They're often carrying things or they might be walking to work and so that's a more purposeful type of behaviour. Then there's the recreational behaviour. In our study in Western Australia what we found was that for recreational walking, for every recreational destination that you gain, so access to a park, access to a sports field, access to the beach, Perth is built along the coast. So if you gained access to any of those destinations, for each one of these that you gained you did an extra 21 minutes of recreational walking. That's very beneficial of course this is over a week, very beneficial. So you only had to have three of those and you'd be doing 60 minutes of recreational walking in a week, fantastic. Now that's across a population.

PETER MARES
That's an average of course, this is statistical, but it shows a huge potential for people to improve their level of activity.

BILLIE GILES-CORTI
So we're very encouraged by those results showing some longitudinal evidence about the importance of the environment and these are all in new neighbourhoods.

PETER MARES
So these are ones that have just been built on the edge of the city as it were?

BILLIE GILES-CORTI
Yes and one thing I guess we were a bit naïve, we're public health researchers perhaps and not planning researchers. That's what we've discovered of course it takes an awfully long time for neighbourhoods to evolve. This study has been going on for 10 years. You still go into those neighbourhoods, shop is coming, public transport is coming, school is coming, it just takes a long time to evolve. But actually it's very consistent with what we've found in cross-sectional research.

PETER MARES
Just to explain the cross-sectional research as opposed to longitudinal, so longitudinal you're looking at people's behaviours over time and how they might change. Cross-sectional is more like a snapshot across a group of people in a moment in time.

BILLIE GILES-CORTI
Exactly, so it's not as valued because we don’t know whether they moved there because it was walkable. But what we're finding actually is our longitudinal results and our cross-sectional results are very much the same. So it's quite plausible that these environments are changing people's behaviour if they're provided with it. So it becomes really important when we're thinking about planning into the future.

PETER MARES
Now this is of course though research done in a specific context, the city of Perth as you described for us, a heavily car dependent city in Western Australia with a warm climate and that sort of thing. How much can these results be generalised to other cities around the world do you think?

BILLIE GILES-CORTI
Well let's just think of some cities around the world. Let's go to Barcelona in our minds, a very walkable, six storey high buildings, very walkable. The environment is so beautiful there that you can't resist, you go outside, you promenade, you go out it's a very walkable environment. If we went to Copenhagen, people cycle there because the infrastructure is all there. It's very compact it's built in a way that not very high rise, three to five storeys high. So these are cities that are great cities.

PETER MARES
The evidence shows that there are higher levels of walking per head of population in those cities than there are in say a city like Perth?

BILLIE GILES-CORTI
Yes certainly the results show that quite strongly that the walking levels are higher and the cycling levels are higher. So where European cities have really focused on trying to introduce really good infrastructure for cycling, protecting cyclists from roads and drivers, having legislation that says if you hit a cyclist then you are at fault, that's the sort of legislation that they have in Amsterdam or in The Netherlands. It's a combination of policy and infrastructure. Where that policy and infrastructure is in place we see people more likely to walk or cycle. I think it's very important for the developing world is thinking about the compact city and trying to avoid, if at all possible, just going for the car as the option. Because if we just focus on motor vehicles as the primary method of people travelling rather than walking, cycling, public transport, the health impacts are likely to be quite significant over time. That's where there is evidence showing that cities where a large proportion of the trips are walking, cycling and public transport trips, the prevalence of obesity is much lower.

PETER MARES
If obesity is lower that is a really strong indication that you're going to have lower levels of type 2 diabetes, cardiovascular disease and those sort of other lifestyle illnesses that are threatening to overwhelm us as an epidemic.

BILLIE GILES-CORTI
Exactly, there's been a very nice study that's come out from China that was looking at changes in time of people gaining access to a motor vehicle. It happened particularly for men, the results weren't there for women but they were for men. So in households where they gained a car, the odds of men being obese doubled. I guess the men were probably driving I'm not sure who was the driver. But the results are showing that for cities that are moving into focusing on the car rather that looking at the alternative, I think there's a big price to pay in terms of the health and wellbeing of residents.

PETER MARES
This is Up Close I'm Peter Mares and I'm speaking with internationally recognised public health expert Professor Billie Giles-Corti about the impact of cities on health. Does the built environment influence our level of physical and social activity and therefore our wellbeing? Billie, we've talked so far really about physical health, about issues like diabetes, obesity, cardiovascular disease. What about mental health? Because there is an argument that if people walk more they also interact more, they meet each other more by happenstance in the street and this helps build a more cohesive community. Is there evidence to back up that assumption?

BILLIE GILES-CORTI
Yes there's quite a lot of evidence, looking at social interaction and the social lubricants that come from when you run into someone with a dog. You can't help but chat to them and so we see that a dog is a social lubricant, that's a really nice way of walking the neighbourhood. It builds social capital it builds a sense of community which are all factors that are related to people's mental health. We've also shown of course that in neighbourhoods where you've got high quality, public open space. One of my PhD students Jacinta Francis, found that people are less likely to have poor mental health outcomes. So low levels of psychological distress when they live in a neighbourhood which has got high quality public open space, not just a piece of green space but nice, high quality, public open space, people have better mental health and wellbeing outcomes.

PETER MARES
Because I think there is evidence too, isn't there, that being in a green space with trees and plants around you is - actually has restorative effects on your mind?

BILLIE GILES-CORTI
It reduces mental fatigue, it reduces stress levels. If you compare people who just walk through a street as opposed to walking in green space, so exposure to nature is meant to be restorative for all the reasons that you describe. There's lots of things going on here and it's to do with interacting with people, being physically active is actually better for mental health. But at the same time independently of that exposure to nature is restorative. So there are lots of different things that can go on in the way we build cities and it becomes very important when we're moving into higher density cities and how we're going to manage that. I do think we need to have high density cities, I think there's probably thresholds about the levels of density that will produce health and wellbeing.

PETER MARES
Well let's talk about that because I mean one of the things you've been suggesting is that a kind of very spread out, sprawling city is bad for our health because it leaves us very dependent on cars and there aren't places nearby that you can walk to. So you're suggesting we need higher levels of density so more people living per hectare or square mile or whatever. But that could also have negative consequences, too, couldn't it? Higher levels of density doesn't that potentially have problems around noise pollution or people's sense of being crowded in or lack of space, those things?

BILLIE GILES-CORTI
Yes I mean we've just done a lovely review on this for the Heart Foundation in Australia. Looking at what are the health and wellbeing outcomes of increasing density. The report is called, Increasing density in Australia: how to maximise the health benefits and minimise any harm. I'm hoping to globalise that so provide some guidance for the developing world as well. But what we've distilled that down into a range of things that we need to think about to get density right. We need to think about the way the buildings are built, so that there is noise attenuation, so that it does stop people from being exposed to noise outside. Heat, light, having access to light is important, but also crime prevention through environmental design. So you're actually building the buildings so that people know who should be there. So you've got lots of people living in the area, but who should be in that area so that you create some sense of control for people who live there. That also has an impact on reducing antisocial behaviour, crime and that sort of thing.

PETER MARES
The whole Jane Jacobs, who was a famous urban policy writer, her idea of eyes on the street. That if people are watching the street and looking at the street and engage with each other on the street this actually reduces crime.

BILLIE GILES-CORTI
Yes they call it natural surveillance, because you've got windows looking out, but there's also this idea that you go from the public space to the semi-private space to the private space and that - if we design buildings in that way people know who should there. There's territorial guardians as one of my other colleagues, Sarah Foster talks about the territorial guardians. I think that's a lovely idea that you've got people who look out for the space and have some control over it.

PETER MARES
But you also talk about people do need that private space as well. I mean one of the concerns about high levels of density, more people living together with more people is that I won't have any privacy anymore.

BILLIE GILES-CORTI
That's the other thing that we've talked about in this in terms of the building design is providing space in those buildings for selective interaction. Now if people don't want to interact and they don’t want to do it all the time they should be allowed to not do it. But of course if you provide selective interaction it might be the community garden. It might be an area that's - people can come together for a drink on a Friday night. Something like that, some space that people can come to where there's selective interaction. You choose to go there if you are parents are living there, you've got places where your kids can play. We've also talked about that actually if families are going to live there we need to be designing for families to live in those places.

There's plenty of examples in the world where, Singapore for example, where this is really thought through. Because people live in high rise, but a lot of countries or a lot of cities are not really designing their high rise for families to live there. It's a temporary thing that people do till they get enough money to be able to buy their house on the fringe or wherever. So we need to be thinking about the building. The other thing we need to be thinking about is who's going to live there. So if children are going to live there, if older people are going to live there, we need to be designing this space to accommodate the sort of people who are going to live in those spaces. That sounds like a silly thing to say. But there is evidence that's showing that we're not building for example teenagers to live in those spaces or children to live in those spaces. If we're not designing for them to live there it's not going to work. When kids get into teenage years and there's no place for them to hang out to bounce a ball to play a game of sport then there's going to be problems.

Then you go to a city like New York and all around that city there's basketball hoops, there are little places where kids can play. There's dog owners there and you go to a city like New York and you'll find that there's places for dog owners to have their dogs in their high rise but they can take it to a local park and a fenced off area for their dog to be able to play with other dogs. We also then need to think about the geographic location of those buildings. Is it going to be high rise sprawl? Is it going to be in places where there's no shops and services, no public transport? Or is it going to be designed in a place that provides people with utilitarian destinations, shops, services, public transport plus recreational? Public open space becomes much, much more important I believe as we densify cities.

PETER MARES
So having all those things, the things you need for your daily life like shops or banks or whatever, access to public transport. But also the recreational opportunities in terms of open space, having all those within a 15 minute walk essentially?

BILLIE GILES-CORTI
Exactly. The only other thing that I add into this and I think it's really critical is in terms of geographic location if we're going to locate high rise housing on busy roads, which for developed countries people are looking at that. On the arterials that seems the most likely place to put it because it's going to cause less concern for residents of neighbourhoods. So the idea you put them on the busy roads, fewer people are going to complain about that.

PETER MARES
Also it's close to public transport, presumably there's buses on those busy roads and that sort of thing?

BILLIE GILES-CORTI
True and that's another good reason, so the public transport is there. I question whether people are really thinking about the recreational public open space and I think that needs to be considered. But I think if we're going to do that we really need to think really well about the way we're designing those buildings. Because if all the balconies are overlooking the busy roads as is wont to do, my observation is that we're not learning from Europe and places where we've got high rise development but it's actually designed for people. So the balconies are not looking over the busy road and the reason why that's an issue of course is respiratory health. That if people have got balconies that are overlooking the busy road, if they open their windows, they're going to get the car fumes that come in which is a major factor contributing to respiratory health. But people are less likely to go out on the street when it's a busy road and that reduces social interactions and its noise as well.
So if we're going to be thinking about putting housing on busy roads we really need to be designing it for social interaction, to reduce exposure to environmental toxins, to reduce noise, all the environmental stressors. So there's a range of things that we need to consider. I think it's the alignment of the building, the social environment and the built environment that needs to be really considered to get this right. I think we can learn a lot from what the evidence is telling us to maximise the health outcomes.

PETER MARES
Let's return to where we started our conversation, which was with the example of John Snow and how his discovery that cholera was being caused by contaminated water led to – eventually - to a revolution in urban design and planning and to proper sanitation and clean water and those sorts of things. Now that was a real revolution, a whole new way of thinking about cities. Are we at a similar point today that we need to really, fundamentally re-think what we do in our cities, how we plan, how we build if we're going to deal with the chronic illnesses of the 21st century?

BILLIE GILES-CORTI

I think the nice thing about what we're proposing here and what we're talking about - walkable, pedestrian friendly cities, they're not only good for health, they're good for the environment, they're good for traffic management. They're good for community, there's a whole range of co benefits and I think actually if we put together the co-benefits argument, we're talking about cities that are for people. I think that's a really nice way of thinking about it is, yes it's going to be good for health but it's going to be good for the sustainability of the planet as well as that. So I think that what we're talking here is a city that is healthy, sustainable and much more liveable.

PETER MARES
It all sounds wonderful, the idea of the much healthier and much more environmentally sustainable and even more sociable city. So why aren't we doing it? What’s holding us back from building this sort of city?

BILLIE GILES-CORTI
I think there's a range of issues that are going on, we've got almost like a business-as-usual. We know what's worked in the past and so we're still providing affordable housing, so-called on the fringe certainly in Australia in the developed world, in the US.

PETER MARES
So we keep spreading our cities every further outwards?

BILLIE GILES-CORTI
Yes and that's seen to be affordable, but of course it's not really affordable living. So if we think that it's affordable but on the fringe we don't have public transport, we don't have shops and services and so if fuel prices go up to what's estimated it's likely to be in the next 10 years when we've got to peak oil, we're going to have a major issue for people living on the fringe not going to be able to afford to live there.

PETER MARES
If they can't fill up their cars any more then they're not going to be able to get around and there's no other alternative.

BILLIE GILES-CORTI
That's right there isn't the alternative. So that's really tricky so why are we doing that? It's because this idea of it being affordable. There's always the pressure from the development industry saying oh we need to have more land released. I think that's such a disastrous thing. I think we need to put an urban growth boundary, we've sent that in Portland in the US.

PETER MARES
So this is the idea you more or less draw a line around the city and say the city will grow no further than this and we have to accommodate growth within these existing boundaries.

BILLIE GILES-CORTI
And we'll fill in and make sure that we have maximum - now the beauty of that of course is that actually that means that we're making the best use of the infrastructure that we've got available to us. I think the other thing is that there's a cultural issue. People in the developing world are now aspiring to have the things that are in the West. While in the West actually people are starting to think, hold on, we're doing this wrong. What you're starting to see a decrease, particularly in young people wanting to drive, an increase in people using public transport. That really happened round 2008 when we had a peak in oil prices. So we're starting to see shifts and I think young people will lead the way in this. I suppose a lot of people, older people actually are moving into cities, into the city, inner city now where they're downsizing.

So I think there's a cultural shift that needs to occur and I think there needs to be more conversations going on in communities. What we tend to get is people being very afraid of density. I can understand it if we don't get it right, which is really why I wanted to do this report on thinking through, what are the factors that will optimise the health outcomes if we increase density. I think it's really important to think that through and I think we probably need guidelines in place to make sure that we're building density that's going to produce good health outcomes rather than actually produce harm. There are plenty of examples in the world where we've had to implode buildings because they were producing harm because of the way the density was built.

So I think there is a chance that we could get it wrong. But I think we've got enough evidence to say well this is the way it should be done. There's a range of things that are resulting in us not moving forward, partly cultural, partly aspirational, and partly business-as-usual. I think we do need a shift. We need the development industry, we need the built environment professionals to really help us pave the way to give some good examples and show that (1) that they work, that they are actually financially viable and I think the banks and the financiers need to really get involved to actually start to value and to see that we're going to get benefit from building cities in a different way. They finance projects, we don't want business-as-usual. Business-as-usual I think is actually going to produce harm in the world. I think we can actually do a much better job.

PETER MARES
Billie, thanks for joining us on Up Close.

BILLIE GILES-CORTI
Thank you very much, Peter, nice to talk to you.

PETER MARES
Professor Billie Giles-Corti is Director of the McCaughey VicHealth Centre for Community Wellbeing in the School of Population and Global Health at Melbourne University. She also holds a principal research fellowship from the Australian National Health and Medical Research Council. \