Dec. 08 2021

Study Shows Success of New York City's Clean Heat Program

Ban of heating oil #6 effective in reducing air pollution

In 2012, New York City established the Clean Heat Program to eliminate the use of residual heating oil which had been identified as a major source of air pollution in the city and linked to multiple adverse health outcomes, including cardiovascular disease. In a study conducted at Columbia University Mailman School of Public Health with colleagues at Drexel University, researchers evaluated the program’s outcomes, including the air pollution reductions between 2012 and 2016, using multiple data sources and rigorous model diagnostics. 

The results showed that the heating oil #6 ban (completed by 2016) was effective in reducing air pollution. The study is the first to provide a framework to evaluate the impact of the Clean Heat Program since it was implemented. The findings are published in the journal Environmental Health Perspectives.


“It is very encouraging to see the overall success of the Clean Heat Program in reducing pollution levels in the city, and particularly exciting to find that the policy is effective in both low- and high-income neighborhoods.” said lead author Mike He, PhD, formerly a Columbia Mailman School doctoral candidate in the Department of Environmental Health Sciences and now a postdoctoral fellow in the Department of Medicine and Public Health at the Icahn School of Medicine at Mount Sinai.

Prior to implementing the new policy, three types of heating oil were used in New York City: heating oil #6, #4, and ultra-low sulfur oil #2. Both #6 and #4 are referred to as residual heating oils. Oil #2, which is the lightest of the three, has been considered a cleaner energy alternative, and any newly installed boilers would have to burn at this lower-polluting grade after the Clean Heat Program came into effect.

The researchers used census tract-level data and air pollution data from the New York City Community Air Survey (NYCCAS), a large urban air monitoring program that measures levels of numerous air pollutants across the city using monitoring units to estimate air pollution levels. Because building fuel conversion began in 2012, the investigators selected the years 2011 and 2016—when #6 was banned—to estimate the pre- vs. post-policy difference in pollutant concentrations.

The researchers observed substantial reductions in the three air pollutants studied—fine particles (PM2.5), nitrogen dioxide, NO2; and sulfur dioxide, SO2—attributable to the ban of oil #6. These reductions were independent of other sources of air pollution in the city, such as traffic and neighborhood-level socioeconomic conditions.


“Given the well-established associations of SO2, PM2.5, and NO2 with numerous adverse health outcomes, the reductions in these air pollutants are likely to result in several potential health benefits and in general improve population health outcomes in New York City,” said Marianthi-Anna Kioumourtzoglou, ScD, Columbia Mailman School assistant professor of environmental health sciences and senior author.

Co-authors include Lyuou Zhang, Elizabeth Gibson, Frederica Perera, Daniel Carrión, and Kimberly Burke, Columbia Mailman School; Gina Lovasi, Jane Clougherty, and Dustin Fry, Drexel University.


The study was supported by the National Institute of Environmental Health Sciences, grants ES029372, ES030616, ES009089, HD049311, and ES09600; Environmental Protection Agency, RD83615401, New York Community Trust, and the John and Wendy Neu Family Foundation.