Despite government uncertainty last month, US satellite imagery has confirmed that haze from Indonesian peat fires that has bedevilled the region did in fact reach the Kingdom in October, with haze from local forest fires likely to succeed it as the dry season progresses, according to an expert’s analysis.

Dr Veerachai Tanpipat, an independent researcher based in Thailand who has worked alongside NASA scientists since 1999, said yesterday that his team made the determination by analysing satellite imagery from NASA, NOAA and the US Naval Research Laboratory.

“Yes, the smoke in Cambodia in the past October was from South Sumatra,” he said in an email.

In early October, the Ministry of the Environment acknowledged that bouts of haze hung over Phnom Penh, but could not confirm whether it was from the Indonesian fires, which some observers have called the greatest eco-disaster of our time.

The fires are being exacerbated by the current El Niño global climate event, and are widely considered to be the worst since 1997 – also an El Niño year – which was the last time haze was suspected to have reached Cambodia.

However, some of the haze over Cambodia last month could also be attributed to local slash-and-burn agricultural practices, Tanpipat said.

Coming changes in wind direction and other seasonal factors mean that the worst of the Indonesian haze has passed, Tanpipat added, but a “very dry” dry season could mean more local forest fires.

“The coming forest-fire season might get more smoke,” he said, adding that NASA satellite imagery from the past decade showed Cambodia has one of the highest-observed numbers of “hotspots”, or active fires, in the region.

Exposure to haze in the short term causes discomfort in healthy individuals, according to the Singaporean Ministry of Health, but long-term consequences include higher risk of heart disease and chronic respiratory conditions such as asthma.

However, accurately determining the consequences of exposure to haze requires air quality measurement, which is still a work in progress, according to Ministry of Environment spokesman Sao Sopheap.

“We are working on it now; we hope it will be up and running very soon,” he said.

According to a 2014 study by Yale University, Cambodia ranks 162 out of 178 countries surveyed for air quality.