PETALING JAYA: More must be done to protect global health by battling the threat of air pollution – as a new study emerges linking long-term exposure to air pollution with increased Covid-19 risks, say health experts.
They say that the findings have once again highlighted the importance of promoting a healthier environment as it has an inseparable connection with health.
Prof Dr Moy Foong Ming from the Social and Preventive Medicine Department, Medicine Faculty, Universiti Malaya, said based on the existing evidence on environment and health, air pollution is recognised as a leading problem for public health and a major environmental health problem around the world.
“Air pollution is the largest environmental cause of disease and early death in the world.
“It has been associated with at least five million premature deaths every year.
“While air pollution impacts everyone, the burden of disease is highest among the poor and the vulnerable ones, minorities, and the marginalised,” she said when contacted.
Moy was asked to comment on a new study released on Nov 13 from the Boston-based not-for-profit research organisation, the Health Effects Institute (HEI), which found that long-term exposure to outdoor air pollution is linked with adverse Covid-19 health effects.
In the study, researchers followed 3.7 million adults in Denmark during the Covid-19 pandemic between March 2020 and April 2021, focusing on five outdoor air pollutants: fine particulate matter – known as PM2.5 (particles of 2.5 microns or smaller), coarse particulate matter – known as PM10 (particles of 10 microns or smaller), black carbon, nitrogen dioxide, and ozone.
A micron is a millionth of a metre, and PM10 or smaller particles can be inhaled and lodged in the lungs, where they can induce adverse health effects.
Their findings showed elevated risks of Covid-19 incidence, hospitalisations and death associated with long-term exposure to PM2.5, PM10, black carbon and nitrogen dioxide.
Researchers did not find associations between exposure to the ozone and Covid-19 incidence.
Risks of increased Covid-19 incidence and hospitalisations were strongest with exposure to nitrogen dioxide, which is largely produced from combustion of fossil fuels, especially in motor vehicles.
The risk of Covid-19 mortality, however, was strongest with exposure to fine particulate matter, for which major sources include industrial and agricultural activities, wildfires and fuel combustion.
Overall, older adults and lower socioeconomic populations had the greatest risk of contracting Covid-19, according to the study.
Moy said that air pollution affects people over their lifespan, causing a wide range of acute and chronic diseases from childhood to old age.
Almost all organs, systems and processes in the human body may be impacted – including the lungs, the heart, the brain, the vascular system, the metabolism and reproduction, she said.
“Promoting an environment conducive to health will definitely improve human health and well being.
“However, this needs multi-sectoral stakeholders to work towards this goal,” she said, adding that combustion of fossil fuels and biomass is the most significant source of air pollution,” said Moy, who added air pollution can be controlled in a cost-effective manner through a combination of policies, legislation, regulation, standards and enforcement coupled with implementing new technologies and increasing social awareness.
“For example, there should be health education and awareness activities carried out in the communities and schools.
“Besides adults, it is hoped that children can also be agents of change for their family members.
“Meanwhile, corporations should be educated, encouraged and provided with incentives if they implement environmental friendly measures,” she said.
Moy added that as a safety measure, the public could monitor the air pollution index in their community and avoid outdoor activities if possible when the index is high.
Assoc Prof Dr Mohd Hasni Jaafar from the Public Health Medicine Department, Medicine Faculty, Universiti Kebangsaan Malaysia cited findings of the WHO, which found that 80% of the disease burden is due to poor environment.
This includes the poor air quality, unhygienic food, unsafe drinking water, poor sanitation and unkempt housekeeping, he said.
“During the early years of the Covid-19 pandemic, it was thought that the virus spread through air droplets or aerosol during speaking, coughing and sneezing.
“But from many studies, including one research at the Hospital Canselor Tuanku Muhriz (HCTM), the virus was found to also spread through fine particulate matter and has the ability to invade all the way down to the alveoli.
“Particulates are formed indoors and outdoors, either naturally or man-made.
“To a certain extent, humans have a significant impact on the quality of the environment,” he said, adding that proactive action should have been taken a long time ago to ensure a healthy environment, not only for the current generation but also for subsequent ones.
Dr Mohd Hasni also said that Covid-19 is an airborne disease which has proven capable of being attached to the surfaces of fine particulate matter up to a week.
“Long-term exposure to air pollution, especially to PM10 or PM2.5, may have a certain extent of disruption on the natural respiratory defense mechanisms like cilia biliary bodies that produce mucus to trap particulate matter and microbes.
“Poor mucus production will increase the risk of infection and secondary bacterial complications.
“Air pollution also destroys defense cells called macrophages at the alveoli, which are important to engulf and kill any foreign bodies – including the Covid-19 virus,” he said.
He added that poor air quality is contributed by many sources, including open burning, smoking, vaping, exposure to occupational smoke, dust and vehicle emissions.
“Saying no to smoking and vaping is actually one brilliant step in preventing Covid-19,” said Dr Mohd Hasni, who added that open burning – especially in agriculture – must be stopped, and that all industries including small and medium enterprises (SMEs) should follow clean air regulations to reduce air pollution, while the use of electric vehicles should be also be promoted.
Dr Mohd Hasni added that as the other 20% portion of the disease burden is dependent on the genetic makeup, nutrition and immune system of a person, such as having a balanced diet as among the arsenal to protect oneself from infections.
“The Health Ministry promotes a healthy diet nearly every day.
“For those not able to tolerate certain foods, supplements are recommended.
“Stop smoking, vaping or taking alcohol.
“Be positive and happy to suppress all stress enzymes like cortisol and adrenaline which normally may interrupt our immune system if they are present at levels that are too high or not at the correct time.
“And wear a mask when you go outside, especially during this time of haze,” he added.