More than half the world's population now lives in urban areas. We know these areas offer amenities and opportunities that simply don't and can't exist in non-urban areas. But unfortunately, these urban areas also bring with them potential environmental health threats as, well as risks associated with reduced health equity. In this module, we'll be exploring how to better promote urban health. Now there's a number of factors that potentially influence urban health. Some of these are intuitive, others maybe not so much. Urban governance is a very important one as are the characteristics of the population living in an urban area. We need to consider both the natural and the built environment. Of course, this would very closely tie in a number of environmental health factors. There's issues around social and economic development, and also services and emergency management for the urban areas. Finally, food security is a key issue with regards to urban health. We have to recognize right away that health risks in urban areas are distributed unequally among different social groups and they are always worst among the most vulnerable groups by definition. Let's think about some potential health outcomes and the causes of them that we might experience in an urban area. Physical inactivity and obesity are two key health outcomes particularly in high-income industrialized countries. We'll talk about those in other modules. We also have factors like cardiovascular and pulmonary disease resulting from air pollution which tends to be worse in urban areas. We can have ischemic heart disease and cancers resulting from the burning of biomass for energy in certain urban areas. Asthma from indoor air pollution and heat-related strokes and illness from heat or both common risk factors here. In cities, we are well aware of the urban heat island effects where cities tend to absorb and retain heat much better than natural areas around them. We also have issues around injuries, for example, dangerous jobs, and traffic are both more common in urban areas. Anywhere we have great population density, we have to worry about communicable diseases. This could include airborne diseases like tuberculosis. Could also include waterborne diseases like cholera and diarrheal diseases in general as a result of unsafe drinking water and/or poor sanitation. We also need to think about health equity. How do we ensure that everyone has equal access to good health? There are a number of factors to consider here as well. So broadly, we can think about the political and economic environment. What is the quality of urban governance? What are the employment opportunities? What access do people have to health services and education? How safe and secure are they? Is there gender equality? We can also think broadly about the physical environment and health equity. So things like the geography of an urban area, the climate, the nature and status of the built environment, housing conditions, access to safe water and sanitation, the existence of transportation systems to allow people to move around, and air quality. Then the third broad category would be social and personal characteristics which also tie into health equity. So things like the age and gender balance of a population, whether or not there's a large proportion of urban migrants or unemployed individuals or slum dwellers, and also cultural factors. Once again and as we saw with environmental health risks, vulnerable groups are likely to have worse health equity as well in urban areas. So unfortunately, as more and more of the world is becoming urbanized, but the resources available to build out cities are inadequate, we have more and more emergence of slums. So slums are defined by lacking access to at least one of the following features. So they lack access to safe water, or they lack access to sanitation, or they lack an opportunity for a safe and secure tenure in this community, or they lack durable housing structures. So they could have 1,2,3 or commonly all 4 of those features. Now slums, here you can see an example photo taken from one. But slums in my experience look very similar no matter where you go in the world. Issues that are related here include informal economies, and as a result, there's reduced access to jobs that are stable and well-paying. There's also social exclusion that comes from the social stigma associated with living in a slum. There's underdevelopment and inability to fully take advantage of available resources, and there's a whole range of environmental health hazards. We've already talked about drinking water, sanitation, air pollution, and injuries. All these things tend to be much worse in slums compared to other non-slum urban areas. How common is it to live in Islam? Well, in 2014, it was estimated that almost 30 percent of the global population lived in slums. Again, increasing urbanization has the potential to drive that number higher. How do we go about actually promoting urban health? So we've already talked about a number of challenges in terms of risks and health equity. But how do we actually promote urban health? We have to acknowledge that healthy cities don't form spontaneously. They have to be purposely and thoughtfully created. So what do we need to do to create a healthy urban area? Well, we need to make sure that we're meeting the basic needs that everybody, regardless of social group has in a community. Access to food, water, shelter, income, safety, and work opportunities. We also need to ensure a clean and safe physical environment in this urban area, and we want to make sure the urban area is surrounded and integrated into a stable and sustainable ecosystem. We'd like to ensure that there's a diverse vital and innovative economy that has great opportunity to grow. We want a high degree of public participation and control input into governance in other words. We want appropriate and accessible public health and health care services. Finally, all of these things should add up to high levels of good health as opposed to just low levels of disease. I want to wrap up here by talking about opportunities that are emerging for modeling urban environmental health. So we always have the opportunity create models based on different frameworks. So combining different components of information. For example, we could focus on urban sustainability, the amount of greenhouse gases that are emitted, urban heat, air quality, traffic, things like this, and put these into a single framework so we can see how they interrelate. So here's a hypothetical example of a dataset that might combine information about traffic, noise levels and air quality, access to services, water quality emissions into air water and soil, safety factors, urban heat, and interfaces between people and their built environment. So modeling presents actually a great opportunity to visualize what urban health and health equity look like and I'll end with an example here from the city of Amsterdam in the Netherlands. So this is a geospatial application of multiple different types and layers of health information that were readily available using open source data. The researchers here use these data and combine them in a way that you can visualize the entire city and start to consider what areas have worse urban health risks or have reduced urban health equity, and how might we go about actually approaching those problems to fix them and improve public health.
