In this module, I'm going to give you an introduction to the built environment. But first, I want you to think about where you live, the structure you live in, the neighborhood, the city or surrounding area. Now think about whether that area and structure and neighborhood are likely to improve your health or maybe harm your health. How would you even go about assessing that? In this module, I'll be giving you an introduction to what we're referring to when we talk about the built environment, but also an overview of how we can go about assessing that to evaluate its impacts on public health. All aspects of the physical places we live and work. So that would include the homes we live in, the buildings that we work or study in, the streets that we get around on, open spaces including parks that we purposely construct for pleasure and leisure, and infrastructure. We know from a large existing body of research that the built environment absolutely influences public health particularly in terms of risk of chronic disease. Part of the reason for that is that a lot of the built environments that we've designed are not good at facilitating health or healthy behaviors. I think it's very difficult to look at a picture of thousands of people sitting in traffic and think, this is a healthy situation. I want to highlight that when we're talking about the built environment, we can come back to our exposure disease framework of source, and movement of pollutants, and human exposure, and dose ultimately leading to an adverse health effect. We need to understand when we're talking about built environment, all of these steps of the exposure disease framework exist within the built environment. So the importance of the built environment to public health has become increasingly apparent over the past 200 years. In the late 1800, we really started to implement for the first time a systematic approach to urban planning, no longer were towns evolving in a completely unplanned fashion. We really started to focus on developing comprehensive sewer system approaches. We needed a way desperately to safely dispose of human waste. In the early 1900 began construction projects of public water and sewer infrastructure here in the United States. In 1927, the Standard City Planning Enabling Act passed. In 1934, the Federal Housing Authority was created and this resulted in major impacts in how urban development occurred. Then in the 1950s and 1960s, the interstate highway system was created that connected our urban areas and we also started to see urban renewal efforts. So let's consider how built environment interrelates with other determinants of health. So the image you're looking at here, I'll refer to as a square onion with many layers. If we look at the very center of that image, you'll see of course that all of us have innate unique features to ourselves, our age, our sex, our race, other biological characteristics. Around those characteristics, of course, we have our individual behaviors which also serve to make us unique. As individuals, we exist within social, family, and community networks, so that's the next outermost ring. Finally, we come to living and working conditions, and so this is where the built environment resides. So we can think about lots different living and working conditions. We've got psycho-social factors, socio-economic status, we have both the natural and built environments, public health services, and access to healthcare. Then all of those conditions exist within the broader social and economic, cultural, environmental, and health conditions and policies that frame our entire lives. So you can see each ring of the onion here basically exists over the entire course of our lifespan, and we may see changes in many of those rings over our lives. So the built environment is considered under living and working conditions and includes things like transportation, and access to water, and sanitation, and housing, and many other factors. How do we go about actually measuring or assessing the built environment? We do this in three major ways. The first are what we call indirect methods. So this would be looking at a community from the outside and trying to get census data or access to geographic information, system data, or maybe looking at the network of streets, or developing from available information from tax rolls, for example, some kind of index of deprivation. We also have so-called intermediate methods, and so these might include, for example, using perceived environment measures that you might actually ask residents to complete, or getting regional land use data from tax assessors or examining aerial photography or looking at existing databases and that could be something as simple as the phone book or as complex as databases available from, for example, the Department of Agriculture. Finally, we come to the direct or gold-standard methods, which typically focus on in-person audits of environmental characteristics in a neighborhood or housing development that are completed by trained observers. Using these various methods, we can come up with ways to rate the built environments. So various tools have been developed that measure the built environment and provide a score or an index on things like walkability, or aesthetics, or safety, or ease of transport, etc. So the image you're looking at here is taken from a website called walkscore.com, and this website focuses on assessing how walkable neighborhoods are. So here we've got a screen capture of the City of New York and you can see the city basically has a heat map of areas that are more or less walkable, but overall the score is 89 out of 100, meaning that New York City is very walkable. So the nice thing about these measurements and scores and indices is that it allows us to do a semi-quantitative or even a fully quantitative comparison of different built-in environment attributes to determine what is most associated with better or worse public health. Finally, I want to wrap up and talk about how we can go about ensuring that the built environments we do construct are healthy, and there's a number of guiding principles we have here. The first is to mix land uses, so we don't want commercial corridors completely isolated from residential corridors such that people have to immediately get in a car if they want to go to the store. We want people they'd be able to walk and be out in their environment under active transportation. We also want to take advantage of compact building design so rather than sprawling endlessly out over an ever increasing area, let's build our buildings in a more compact fashion. It's absolutely critical that we create a range of housing opportunities and choices, especially when we have to consider low income individuals who are most vulnerable and absolutely need access to affordable quality housing. We need to foster distinctive attractive communities with a strong sense of place. No one really wants to live in a neighborhood where you say, "Meh". We all want to live in a neighborhood that's very special and unique and welcoming. We want to preserve open-space and farmland and natural beauty as well as critical environmental areas, so not everything needs to be built. We also want to direct development towards existing communities wherever possible. So rather than letting an existing community decay and building a fancy new community, let's invest those resources in making the existing community better. We absolutely need stakeholder collaboration and the people in the community need to have a strong voice in their public governance. As I alluded to you earlier, we also want to create wherever possible very walkable neighborhoods so people can get out and enjoy the benefits of exercise. There are additional factors we need to consider. We want to increase physical activity opportunities for people because there are many health benefits associated with that. At the same time, we want to reduce injury likelihood. We want to increase access to healthy food and generally improve air and water quality. Going forward, we want to make sure we're designing our built environment to minimize the impacts of climate change. We want to decrease mental health stresses wherever possible. We also want to focus on strengthening the social fabric of community because again, it's often that social fabric that creates a community that's welcoming and interesting and desirable to live in. Finally, we absolutely want to improve and achieve health equity and provide fair access to livelihood, education, resources, and good health. So hopefully you now have a better sense of what I mean when I say built environment and of some of the impacts the built environment can have on our health and how we can go about assessing those, identifying problems and addressing them so we can improve public health simply by the way we design our built environment.