KUALA LUMPUR, Sept 23 — The most severe episode of the annual haze season in recent years has increased concerns about regular and prolonged exposure to the chronic air pollution among Malaysians.

While immediate health risks such as breathing difficulties and well as ear, nose, throat and eye irritation in the short term are known, frequent and extended could result in more severe and even potentially deadly complications and diseases.

These may include cancer, heart attacks and stunted physical and mental development.

Respiratory specialist Dr Helmy Haja Mydin from Pantai Hospital Kuala Lumpur warned that even the shorter-term effects could have serious repercussions due to prolonged breathing of pollutants suspended in the air.

"The health risks associated with particulate matter of less than 2.5 microns in diameter (PM2.5) are well known. These are capable of penetrating deep into lung passageways and entering the bloodstream leading to effects on the heart, brain and lungs,” Dr Helmy told Malay Mail.

"It's a known risk factor for lung cancer. Lungs-wise, haze can lead to reduced lung function, increased respiratory infections and more asthma attacks.”

Dr Helmy said there was added danger to expectant mothers who may birth underweight infants or premature babies.

Children were at higher risk of developing long-term issues as their exposure is magnified by their more rapid breath intakes, he explained.

Dr Rohan S. Shanmuganathan, a physician at Klinik Kesihatan Taman Medan, said regular exposure to the haze could also lead to relapses of breathing illnesses such as asthma that may have gone dormant in sufferers.

"It'll trigger allergies, asthma and chronic lung disease. If goes on year after year those with no issues can get allergic symptoms and contract rhinitis and conjunctivitis,” Dr Rohan told Malay Mail.

Long-term risks also include underdeveloped lungs in children leading to future breathing illnesses and higher probability of cancer, said Dr Thomas Koshy, a physician from Sungai Buloh Hospital.

Dr Thomas cautioned that such risks must be seriously considered as Malaysians may not be significantly minimise their exposure to air pollution from the haze even if they avoid the outdoors.

"There aren’t any studies to suggest staying indoors is definitely going to reduce the risk of respiratory problems but continued exposure to unhealthy levels of API will bring on higher risk of heart attacks,” he told Malay Mail.

Damage to the lungs could also accumulate due to the seasonal nature of the haze crisis, he warned when saying that the pollution would take its toll on health even if this was not immediately apparent.

Comparing the lungs to the liver, he said the former could not regenerate and heal like the latter.

"They don't fully recover. [For example] even if you stop smoking, your lung functions will get better but it won’t be a hundred per cent,” he explained.

All the doctors advised staying indoors when possible and to take measures to reduce air pollution and contaminants in such areas.

Dr Rohan suggested ensuring that fans and vents are regularly cleaned to ensure they do not contribute to the air pollution indoors.

"Air purifiers and humidifiers are advertised to help clear the air of particles, so should help clean up the internal environment,” he said.

For Dr Thomas, he said there has been a definite increase in the incidence of breathing problems since the haze started but said it was difficult to determine if these were due to the prevailing air pollution or contributory factors such as smoking.

Nevertheless, he said the public should take steps to protect themselves even if the links between the haze and lasting health problems could not yet be conclusively shown.

"I urge the public for the benefit of their long-term health to wear a face mask  if you’re going outdoors.”

Malaysia continues to grapple with haze almost every year, with this year set to be as bad as 2015, exacerbated dry weather patterns.

The status quo between Asean members has yet to bring forth any change, leading Putrajaya to consider tabling laws to punish those responsible for open burning and forest fires that cause the smog.