Chap. 6: Human Health & Urban Inequities
People create cities having a peculiar range of unnatural environmental conditions, shown in previous chapters, and here I cover health-related heat and pollution in cities. I then provide examples of the stark socioeconomic inequities of these conditions, mirroring inequities in the provisioning of urban natural areas.
Health problems arise from both heat and air pollution, with one dramatic example being an extreme heat wave that increased mortality rates in the elderly population. More subtle problems arise with air pollution, which increases heart attacks in the summer and pneumonia in the winter. Asthma represents another chronic problem, with high levels of either ozone or sulfur dioxide increasing the odds of suffering childhood asthma by 50% or more. Still, plots of asthma incidence and pollutant levels don’t have a clear signal; that is, the connections between the two issues are hard to uncover.
Given these urban environmental problems, one must still balance them against fundamentally different age-dependent mortality patterns for different genders and socioeconomic groups when seeking solutions and allocating scarce resources. Air conditioning provides a technological solution that clearly reduces heat-related mortality, but even that simple measure shows an inequitable socioeconomic distribution. Also bear in mind the results from previous chapters showing heat and energy use in cities: Air conditioning use sharply increases our peak demand on hot days, potentially exacerbating the problem with emissions from power plants.
This chapter also explores the variation in a number of socioeconomic variables, along with distributions of urban environmental features, such as urban nature and aspects of health. Several specific studies demonstrate vegetation inequities based on income in Durham, North Carolina, Milwaukee, Wisconsin, and Baltimore, Maryland. This inequitable distribution of vegetation extends to features correlated with income,such as rentership and education. Mechanisms underpinning these inequities have many origins, sometimes going back to landscaping decisions made decades earlier by previous homeowners.
Inequities in urban nature go beyond private “holdings” of vegetation to low levels of public park access for poor people in Los Angeles. Perhaps more surprisingly, cases show that wealthier people live in areas with higher plant species richness, meaning an inequitable distribution of biodiversity. As shown in the previous chapter, clear benefits result from having views of and access to nature, meaning that all of these environmental inequities, taken together, lead to other inequities, including physical and emotional health. It remains a question for urban areas to address how important, or strong, these benefits are within a broader context of urban citizens’ lives.