Author(s): Birgitte Messerschmidt. Published on May 7, 2020.

The Full Picture

Understanding fire's environmental impact has never been a research priority. That is changing.


Last year, the world watched in horror as Notre Dame Cathedral in Paris went up in flames and partially collapsed. While many observers understandably focused on the prospects of losing valuable and irreplaceable historical artifacts, another big problem was playing out: a potential environmental disaster.

The cathedral’s roof, which was destroyed in the fire, contained more than 200 tons of lead. As it melted in the blaze, toxic lead oxide was dispersed with the smoke and settled on surfaces and into the soil across Paris. An investigation a month after the fire found that lead levels in some public spaces, including streets and plazas, were 60 times greater than what is deemed safe. Soil contamination in public parks and contamination of the river Seine was also of concern.

While there’s no doubt that loss of life and property are the immediate concerns during a fire, the Notre Dame incident is a good example of why researchers and public officials must consider all of fire’s potential effects if they hope to obtain a complete picture of its impact. This broader impact has not traditionally been captured or measured in our reports from NFPA Research, largely because high-quality data to measure these effects is scarce and because there are no standardized ways to collect it. But we are working to change that.

“Research Roadmap: Environmental Impact of Fires in the Built Environment,” a recently published study managed by the Fire Protection Research Foundation, paves the way to improving our understanding in these areas. As part of the project, a team of researchers from Sweden, France, and the United States developed a state-of-the-art summary of what we know about the environmental impact of fires and included a research roadmap proposal to close identified gaps. The study identified the critical need for research, with the lack of data being perhaps the most significant hindrance.

Estimating the consequences of fire’s environmental impact is incredibly multifaceted and includes emissions to air, soil, and water. Every fire produces smoke, which includes carbon monoxide and carbon dioxide, soot, and particulates. Depending on what is burning, the smoke can include many other toxic gases and substances, all of which can be dispersed over large areas. Currently, we don’t have a sufficiently accurate picture of the quantities of these emissions—and even if we did, we don’t yet know what levels of exposure of certain chemicals are tolerable to the environment, leaving us unable to set policies for what is acceptable. In addition to smoke, runoff from fire extinguishing activities can pollute local water sources, and the debris from the fire itself can be a toxic hazard.

It’s not just large fires we need to consider—the thousands of small fires that occur daily around the world impact their local environments as well, and the cumulative effect of these events is not well understood. The recent Foundation study emphasized the need to develop cost-based impact modeling to quantify the investments necessary to better mitigate the potentially costly environmental impacts of fires. The fundamental building blocks of such cost models are available, but the aforementioned input data is incomplete or out of date.

This study and the related work that will come from it are critical. In addition to the obvious environmental benefits, a better understanding of the impact of fire relative to other societal challenges will help policymakers make informed decisions about the public safety investments that should be prioritized, and where we can get the most benefit. At NFPA we will use this research roadmap to guide our future efforts and investments in this important and emerging area. To read the report, visit

Birgitte Messerschmidt is the director of applied research at NFPA. Illustration: Michael Hoeweler