A recent study conducted in U.S. households with gas or propane stoves has revealed that high levels of nitrogen dioxide are being emitted, posing serious health risks for residents. Even after the stove is turned off, pollutant concentrations remain high in bedrooms, affecting the entire family. Breathing in high levels of nitrogen dioxide over time can exacerbate asthma attacks, inhibit lung development in children, and potentially lead to premature death. The researchers estimate that the combination of pollutants emitted from gas stoves may be responsible for up to 200,000 childhood asthma cases, with a quarter of these cases attributed to nitrogen dioxide alone.
The study found that the amount of gas burned in the stove is the biggest factor influencing exposure to nitrogen dioxide. Additionally, the effectiveness of a range hood and its use also plays a crucial role in reducing exposure levels. Long-term exposure to nitrogen dioxide in homes with gas stoves can lead to thousands of deaths annually, potentially accounting for as much as 40% of deaths linked to secondhand smoke. The estimate is based on new measurements and calculations of nitrogen dioxide exposure from gas stoves and data on deaths from long-term exposure to outdoor NO2 regulated by the EPA.
The study utilized sensors to measure NO2 levels in over 100 homes of various sizes and ventilation methods before, during, and after stove use. By incorporating these measurements into a model that simulates airflow and contaminant transport, the researchers could estimate nationwide exposure levels under various conditions. The results showed that the typical use of a gas or propane stove increases nitrogen dioxide exposure by an estimated 4 parts per billion annually, nearing the level deemed unsafe by the World Health Organization for outdoor air. This highlights the importance of reducing indoor pollutants through proper ventilation.
The research is part of a series examining indoor air pollution from gas stoves at Stanford University. Previous studies have focused on emissions of other pollutants from gas stoves, such as methane and benzene. Understanding the impact of stove emissions on human health requires measuring the pollutants that people are actually breathing. The study confirmed that food cooking in a hot pan emits particle pollution but does not produce nitrogen dioxide. Electric stoves, on the other hand, do not emit NO2, making them a safer alternative for reducing pollutant exposure.
Home size also plays a significant role in nitrogen dioxide exposure levels, with smaller homes experiencing higher concentrations compared to larger ones. People living in homes smaller than 800 square feet are exposed to twice as much NO2 compared to the national average. Additionally, exposure to indoor air pollution from gas stoves varies across racial, ethnic, and income groups, with higher exposure seen among certain communities. This further exacerbates existing disparities as exposure to outdoor sources of nitrogen dioxide pollution is also higher in poorer, minority communities. Addressing these disparities is crucial for improving indoor air quality and protecting public health.
