Presenting Author: Carina Gronlund, MPH, PhD, University of Michigan School of Public Health

ABSTRACT

Background: Identifying characteristics of vulnerability to high temperatures will aid climate change adaptation efforts. Previous research is mixed on air conditioning (AC) effects on heat-associated health outcomes. Most prior studies lack individual-level AC ownership and housing information.

Objectives: To understand how housing types and central AC ownership modify associations between high temperature (mean daily temperature > 23 degC) and natural-cause mortality among individuals 65 and older in Cuyahoga and Lucas County, OH.

Methods: The Ohio Department of Health provided daily mortality data, including geocoded residential address. Parcel-level housing data were obtained from county tax assessors and geocoded. We defined four non-AC and one AC housing type. Temperature, averaged over lag days 0-3, was modeled from 1-km-resolution satellite-derived land surface temperature and Weather Underground and airport air temperature. We used a case-crossover design, with controls within the same half-month as the case. We interacted temperature, a linear spline with a knot at 23 degC, with housing type, value-per-square-foot, and decedent age.

Results: Mortality risk increased 11% (95% CI: -18%, 51%), 30% (8%, 57%), 26% (5%, 52%), and 60% (10%, 134%) with each degree above 23 degC for residents of non-AC homes < 2 stories without basements, < 2 stories with basements, 2-4 stories, and >= 4 stories, respectively, controlling for decedent age, marital status, and value-per-square-foot. Risk increased 5% (-2%, 12%) in AC homes.

Implications: Lack of central AC, particularly in mid-to-high-rise housing, increases risk for heat-associated mortality among the elderly. Interventions should focus on households with these characteristics.

Authors: Carina Gronlund, MPH, PhD; Marie O'Neill, PhD; Amy Schulz, PhD; and Veronica Berrocal, PhD.