Urban Planning, Exercise & Energy Consumption
A well-tested strategy in cities where the combined health effects of heat and air pollution are often compounded is heat and pollution early warning systems. A more long term strategy involves mitigating the urban heat-island effect, the tendency for buildings and pavement to absorb more heat during the day and radiate heat at night. The heat-island reduces physiologically important cooling overnight and further stresses energy intensive air conditioning. In Asia, urban heat island effects have been linked to increases in respiratory hospital admissions. In the USA., the rate of increase in number of extreme heat events was more than double in the most sprawling urban regions than in the most compact cities. More work is needed to evaluate the health-adaptive opportunities that planned urban design affords.
Researchers have begun to model the air quality and health benefits from enhancing residents' ability to walk or bike to schools and workplaces via "active transportation" that substitutes these zero-carbon emissions trips for more vehicle-centric travel. In one example from the urban transport sector, Woodcock and colleagues estimated that replacing current vehicles used on short trips in London with low emission vehicles, walking and cycling could reduce ischemic heart disease by almost 20% while significantly reducing GHG emissions. A U.S. study that looked at the effect of substituting 50% of short (8 km round trip) car trips with bicycle trips estimated $8 billion/year in combined benefits from improved ozone and PM2.5 air quality, reduced health care costs, and improved physical fitness. In lower-income countries as well, switching to cleaner fuel sources can yield impressive economic and health benefits. Promising "triple-wins" can be achieved in increased personal fitness from more activity, improved respiratory health with lower co-pollutant emissions from less fossil fuel combustion, and simultaneous GHG reductions.
Designing more walkability and green spaces into our cities enhances neighborhood cohesion, increases social capital, improves the quality of urban living and may contribute to local food security, while reducing emissions, the urban heat island and overall energy needs. Linked monitoring data on local and regional air quality, energy consumption, personal energy and transportation choices, and health outcomes could yield better understanding of how energy consumption and air pollution co-vary on hot summer days, and help further quantify more of the benefits to be gained from moving toward less-polluting energy sources.