To evaluate health issues associated with extreme heat, CDC assessed cardiovascular and hypertension mortality and diabetes. Ms. Prudent noted that the literature supports a fairly strong relationship between heat vulnerability and cardiovascular mortality. With extreme events, pre-existing chronic conditions tend to be exacerbated—a concern given the large demographic shift from a younger population to an elderly one in the region. When heat events do occur, there tends to be a corresponding spike in cardiovascular deaths. This is somewhat due to public health departments classifying these deaths as cardiovascular in nature rather than due to hyperthermia. Flood-related health effects tend to be more difficult to understand, and there has been little research to date on this issue; however, some data are available on displacement associated with flooding.
CDC developed several vulnerability maps of the county to identify communities at risk of impacts from extreme heat and flooding, Ms. Prudent said. The purpose of the maps was to assist city planners in thinking about land use; for example, to determine where to plant trees to lessen the urban heat island effect. Two areas were identified as having high vulnerability—both socially and in terms of the built environment—due to extreme heat events and their resulting negative health outcomes. The high vulnerability was driven by population demographics. One area includes a poor, traditionally minority community. Another area highly vulnerable to extreme heat included a community with a significant elderly population. The agency also developed vulnerability maps for flooding, and found that an indicator for a highly vulnerable community was one that is traditionally minority and had experienced flooding in the past.
It is important to look at vulnerability assessments not only from the perspective of science but also from the perspective of a community’s human and cultural dynamics, said Ms. Prudent. These dynamics offer an appreciation for the community and understanding of the implications of policy decisions. Also, without understanding the community, it may not be possible to gain the buy-in needed to successfully implement policies.