Honduran city’s air pollution is almost 50 times higher than WHO guidelines

The air quality in San Pedro Sula, the second-largest city in Honduras, as been classified as the most polluted on the American continent due to forest fires and weather conditions aggravated by El Niño and the climate crisis.

IQAir, a Swiss air-quality organisation that draws data from more than 30,000 monitoring stations around the world, said on Thursday that air quality in the city of about 1 million people has reached “dangerous” levels.

IQAir found that levels of PM2.5 – dangerous air particulates of less than 2.5 micrometres in diameter – reached 249.1 mcg/m³ this week. World Health Organization guidelines state that annual mean concentrations should not exceed 5mcg/m³.

Honduran authorities have raised the threat level to its highest in most of the country’s departments because of the public health risks, and advised people to close windows and stay indoors to avoid exposure to contaminated air.

Education secretary Daniel Sponda said public and private schools were to be temporarily closed due to the “risk to the physical integrity of the educational community”. The health secretariat has registered an increase of 20% in patients with respiratory infections.

“We have seen a steep increase in respiratory emergencies, especially within vulnerable populations, such as children and senior citizens,” said Dr Cristobal Bustamante, the national director of the emergency medical unit of the Honduran Permanent Contingency Commission, . “We have also recorded an increase in cardiac complications and exacerbated asthma.”

Bustamante said high levels of air contamination can harm the airways, ranging from irritation and inflammation to cell damage and aggravation of existing respiratory diseases.

The clouds of air pollution hanging over Honduran cities have been so thick that in the past two days, several planes due to land in San Pedro Sula were forced to divert to neighbouring countries because the pilots could not see the runways. A number of airports in Honduras have since had to close.

“We have never had to shut down the airport due to the air quality, so it’s a first for us,” said Abraham Manun, the head of operations at the Ramón Villeda Morales international airport in San Pedro Sula. “It’s out of our hands and disrupts the entire flight commerce into and out of Honduras, which mainly flows through our airport. We had to cancel or reroute five international and 12 national flights. There is nothing we can do about it but wait.”

The air contamination has been caused by aggressive temperature spikes during the El Niño phenomenon, which has affected “the dry corridor” that crosses through Nicaragua, Honduras, El Salvador and Guatemala.

El Niño increases temperatures and decreases rainfall, driving droughts, especially across the dry corridor. More than 3.4 million people in Central America depend on aid, and experts warn that El Niño will reach extreme levels this year, putting more people at risk than ever.

Due to the dry climate and intense heat, Honduras is experiencing a sharp rise in wildfires. The Forest Conservation Institute of Honduras has documented 2,598 fires that have devastated 211,292 hectares (5.2m acres) across the country in 2024.

At the end of March, La Tigra national park, known as “the lungs of Tegucigalpa”, was almost completely destroyed by fire, severely affecting the vulnerable ecosystem close to the city.

“This contamination is linked to the gradual effects of climate change coupled with El Niño, which has caused the conditions for wildfires and droughts,” said Juan José Reyes, the head of Copeco’s early warning system. “The lack of wind allows the smog to hover over the cities, many of which are located in valleys.”

Reyes added that if Honduras does not change its environmental policies, the phenomenon could become a regular occurrence and threaten millions across the Central American region.

Nelson Aly, of the International Federation of the Red Cross, said climate-related disasters were happening across Central America. “Climate change has pushed us increasingly into these weather extremes,” he said. “We anticipate a sharp increase in climate-related catastrophes across Central America this year and in the future.

“We are training our response units and bracing for floods like we have seen in Brazil this month.”