Reductions in Respiratory Hospital Visits after a Coal Coking Plant Closure: A Natural Experiment

Rationale: Abrupt air quality improvements have followed the closure or dramatic emission control of large air pollution sources. These “natural experiments” provide ideal opportunities to assess the real-world health benefits of air quality improvements. The shutdown of the Shenango coking plant, a significant fossil-fuel pollution source located on an island in the Ohio River near Pittsburgh, PA, presented such an opportunity to test for changes in respiratory health in the local community following the closure.

Objectives: To identify and quantify the immediate and/or longer-term changes in respiratory hospitalizations and emergency department (ED) visits among the population residing near the Shenango coke plant at the time of its closure.

Methods: We acquired data for respiratory hospitalizations and ED visit counts by residents living in zip codes surrounding the plant, as well as at comparison control sites, three years before and after the shutdown date. The immediate and longer-term changes of respiratory health outcomes were tested with an interrupted time series model, and compared with external control sites and internal control outcomes.

Measurements and Main Results: We found the closure of the Shenango plant was associated with an immediate 20.5% (95% CI: 12.8%-27.6%) decrease for weekly respiratory ED visits, and an immediate 41.2% (95% CI: 14.4%-59.9%) decrease in pediatric asthma ED visits, followed by an additional 4% per month longer-term downward trend. Longer-term reductions, as compared to pre-closure trends, were also observed for chronic obstructive pulmonary disease hospitalizations.

Conclusions: Our study provides strong confirmation that reductions in fossil-fuel-related air pollution produce both short and longer-term respiratory health benefits. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)