Philip Demokritou, the senior author of a recent study, highlighted that it is the first to document how wildfire nanoparticles affect megacity microclimates, potentially exacerbating the urban heat island effect and increasing exposure to air pollution.

During the summer of 2023, smoke from Canadian wildfires led to severe air quality problems and unprecedented cooling in the northeastern United States, particularly impacting New York and New Jersey.

A study conducted by Rutgers University found that this smoke caused 'global dimming,' which reduced sunlight reaching the Earth's surface and resulted in a temperature drop of 3 degrees Celsius (5.4 degrees Fahrenheit).

The cooling effect of the smoke created a 'smoky umbrella' that trapped air pollutants near the ground, blocking solar radiation and restricting natural air circulation.

Additionally, research indicated that residents inhaled 9.2 mg of smoke particles, which impaired immune cell viability and increased the risk of respiratory infections.

In New York City, particulate matter levels soared to more than three times the Environmental Protection Agency's guidelines and were eight times higher than the World Health Organization's recommended levels, leading to health issues such as increased asthma and emergency hospital visits.

Demokritou pointed out that the frequency and intensity of wildfire events have significantly risen due to extreme drought and heat, suggesting that this incident may not be an isolated case for the Northeast U.S.