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Health Shocks Driven by Air Pollution in Sao Paulo, Brazil, Found to Disrupt Health Care as a Result of Limited Capacity

Since developing countries have both lower levels of hospital infrastructure and serious health shocks driven by air pollution, how responsive are their health care systems to these health shocks? In a new study, researchers examined the consequences of air pollution-induced health shocks in Sao Paulo, Brazil. The study found that even transitory health shocks can disrupt health care services as a result of limited capacity.

The study, by researchers at Carnegie Mellon University, the University of Michigan, and the University of Sao Paulo, is published as a National Bureau of Economic Research (NBER) Working Paper.

“Shocks to health care systems are transitory and may be marginal relative to other health demands, so health care systems might be able to manage them,” says Edson Severnini, associate professor of economics and public policy at Carnegie Mellon’s Heinz College, who coauthored the study. “But with limited capacity, hospitals may not be able to respond rapidly, which may exacerbate health damages from pollution. We sought to find out the actual effects.”

Researchers examined health care system responses to daily air pollution shocks in Sao Paulo, one of the 10 largest metropolitan areas in the world and known for its traffic congestion, high building density, and poor air quality. They focused on the effects of short-term exposure to PM10—particulate matter 10 micrometers or less in diameter—on pediatric (one- to five-year-olds) hospitalizations from 2015 to 2017, analyzing the impacts of air pollution shocks on hospitalizations for respiratory illnesses and for conditions seemingly unrelated to pollution. Children are more vulnerable to health shocks than adults, and the shorter exposure period and more limited geographic mobility of children make it easier to determine the effects of pollution on them than on adults.

Data came from the Brazilian Ministry of Health, the Environmental Protection Agency of the State of Sao Paulo, and the Brazilian Hospital Data System. In all, approximately 200 hospitals were part of the study.

The study concluded that pollution created transitory health shocks that generated excess hospital demand. Hospitals linked to the areas hit by the pollution shocks seem to have absorbed most of the increased demand, except those that were capacity-constrained to begin with. These hospitals  were unable to accommodate additional admissions even for emergent respiratory conditions and turned away patients with illnesses seemingly unrelated to pollution for elective procedures, suggesting that they shifted attention to sicker patients.

More importantly, the authors note, health outcomes appear to have deteriorated in the metropolitan area. Hospital readmissions, admissions to intensive care units, and mortality increased. Although the health care system seems to have accommodated some of the increased demand caused by pollution, operating the system under pressure turned out to be detrimental to public health.

The authors note that their study did not include data for out-of-pocket and insured hospitalizations, so the wealthier portion of the population may not be represented in their findings.

“Our findings highlight potential challenges that Sao Paulo’s health care system may experience in the coming decades because of climate change,” explains Bruna Guidetti, a Ph.D. candidate in economics at the University of Michigan, who coauthored the study. “They may be useful to policymakers who want to improve health care emergency preparedness.”

The study’s findings may also apply to health shocks from climate change. “Although we focused on air pollution, the pattern and order of magnitude of the hospitalization swings for air pollution were similar to those for heat weaves, a global environmental insult that is rising with climate change,” notes Paula Pereda, professor of economics at the University of Sao Paulo, who coauthored the study.

The study was funded by Carnegie Mellon’s Heinz College, a CNPq Research Productivity Fellowship, and a FAPESP Project.


Summarized from an NBER Working Paper Series, Health Shocks Under Hospital Capacity Constraint: Evidence from Air Pollution in Sao Paulo, Brazil, by Guidetti, B (University of Michigan), Pereda, P (University of Sao Paulo), and Severnini, ER (Carnegie Mellon University). Copyright 2024 The Authors. All rights reserved.

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