Lung cancer rates have surged by 50 per cent in Thailand as smoke from farm burning blankets the country.

Officials said that lung cancer deaths in the north of the country - the area hit worst by PM 2.5 pollution -have soared from 20.3 per 100,000 people in 2010 to 30.7 in 2019.

Associate Professor Chalerm Liewsisakul of Chiang Mai University's Faculty of Medicine said the last decade has seen a 'notable deterioration in air quality in the region correlating with an increase in lung disease cases'.

Medics said that lung cancer in young people had also risen in the areas blighted by air pollution which 'suggests a direct link to prolonged exposure to PM2.5 particles'.

The study by Chiang Mai University also looked at emphysema patients in one region of the city. It claims that exposure leads to cellular changes, 'hinting at the potential for genetic mutations and cancer development'.

They said that they had seen a spike in respiratory problems, with serious conditions like emphysema, coronary heart disease, and strokes becoming more common during high pollution periods.

The study claimed that there is a 1.6 per cent rise in deaths for every rise of 10 microgrammes of PM 2.5 particles per cubic metre of air.

The World Health Organisation (WHO) puts the safe levels of PM2.5 at five microgrammes but Chiang Mai has become the worst in the world in recent weeks, often recording levels as high as 100 microgrammes per cubic metre - more than 20 times the safe limit.

It has been consistently rated the worst city in the world for air pollution by Swiss group IQAir.

Dr. Sakarn Bunnag, the Deputy Director-General of the Department of Medical Services at Thailand's Ministry of Public Health, has highlighted lung cancer as a public health concern in northern Thailand, with an average of 2,487 new cases and 1,800 deaths annually in the region.

Professor Chalerm Liusrisakul said: 'This problem, which has been going on for over a decade, is expected to worsen, resulting in more hospital admissions.

'Analysis of lung cancer mortality rates from 2010 to 2021 across various regions reveals that the northern region, notably Chiang Mai and Lampang provinces, experiences the highest death rate from lung cancer.

'Furthermore, research indicates a disproportionately higher prevalence of lung cancer cases among young individuals in the northern region compared to other areas.

'This disparity is strongly correlated with PM2.5 exposure, consistent with global findings that prolonged exposure to PM 2.5 significantly elevates the risk of lung cancer.'

Dangerous levels of deadly PM 2.5 particles are recorded every year in Thailand between December and April when farmers across Southeast Asia burn waste crops to clear their land.

The rudimentary method, known as 'slash and burn', is quicker and cheaper than modern machinery, leaving relatively poor landowners unwilling to heed environmental and health concerns over economic necessity.

Despite paying lip service for several years, politicians have failed to stop individuals from burning their land due to it being cheaper and easier than modern farming methods. They also facing pressure from the lucrative agricultural industry, which profits from the soaring demand for food.

In March 2023, the Public Health Ministry of Thailand reported that around 1.3 million people in the country had been unwell due to the rising levels of air pollution. Officials said 200,000 residents were hospitalised in a single week.

Researchers from Peking University in Beijing, China, found that exposure to PM 2.5 air pollution is associated with an increased risk of lung cancer.

In December, Dr Krittai Thanasombatkul from Chiang Mai - one of the world's worst cities for air pollution - died of lung cancer. He had previously blamed PM 2.5 microdust particles for his condition.

The New York State Department of Health says PM 2.5 also increases the risk of heart disease, asthma, and low birth weight.

Medics from South Korea published research in the National Institute of Health in the United States that said the pollutant increases the risk of stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD), lung cancer, and other illnesses such as immune deficiency and even obesity.