America’s power grid is aging. Questions about the vulnerability of the grid abound, and the frequency of power blackouts is expected to increase.
Novel research from Prof. Michelle Bell
at the Yale School of Forestry and Environmental Studies and Dr. Brooke Anderson at Johns Hopkins University examines the relationship between power outages and mortality. The study finds that, in August of 2003, during the largest U.S. blackout to date, both accidental and disease-related deaths increased significantly in New York, New York.
Dr. Anderson explains, “Little is known about how blackouts affect human health, but blackouts could become more frequent due to growing energy use stresses and climate change. Additionally, energy infrastructure may be targeted by national security threats. Our study indicates that power outages can immediately and severely harm human health.”
Using mortality data from 1987 to 2005, Anderson and Bell constructed a statistical model to calculate expected mortality rates had the blackout not occurred. They considered confounding effects, like temperature, day of the week, air pollution, and mortality trends over time.
When the researchers compared their expected mortality rates to the actual number of deaths that occurred during and immediately following the power outage, they attribute 90 excess deaths to the blackout. The majority of these deaths were non-accidental or, in other words, disease-related. They accounted for 78 of the 90 deaths and increased by 25% when compared to non-blackout periods. Accidental deaths accounted for 12 of the 90 deaths and spiked 122% when compared to non-blackout periods.
This is the first study to analyze how disease-related deaths are affected by power outages. Previous work focused on accidental deaths, and, in fact, the NY City Department of Health and Mental Hygiene reported only six deaths directly attributable to this blackout, the majority from CO poisoning.
Prof. Bell describes how power outages could cause health responses beyond accidental deaths, explaining, “Blackouts can produce a wide range of emotional and physical stressors, as people are trapped in subways, and do not have normal access to water, pharmacies, emergency services, or elevators. During this blackout, firefighters performed about 800 elevator rescues.”
The journal Epidemiology will publish the study in its March issue. Grants from the National Institute for Environmental Health Sciences and the Environmental Protection Agency supported the research.
Kathryn Siegel is a third-year joint degree candidate at the Yale School of Management and School of Forestry & Environmental Studies, focusing on corporate environmental strategy. She is a student reporter for the Yale School of Forestry & Environmental Studies’ Communications Office.