Air pollution: Needs economically sensitive quality guideline26 December 2022
Md Firoz Khan, PhD :
Air pollution has become a part of our daily life. People from every walk of life are familiar now with the changes in air quality. This issue is connected to the deterioration of public health during the winter episode each year in Dhaka and other Asian Cities. In the current context, should we care for clean air or blue sky over Bangladesh?
As we see, the messy mode of transportation in the cities is our great concern in daily life. An appropriate discipline or transport model in this sector may help to limit the emission of certain gases and particle pollution. An engine with a total efficiency of energy use is essential on the roads and in the manufacturing plants and will drive the economy very smoothly. An older or faulty engine could play a death trap for the people working with it. Regulatory bodies from the Government (DoE, BRTA, Ministry of Health, Municipal Authority) may work together and take care of this sector which has already become a daily concern of the people for their work and health. Delays on the road will cause more prolonged exposure to toxic gases and particles. Who is most vulnerable to this situation? In my eyes, children are most suffering from road emission exposure. Their respiratory and many other organs are premature, which may result in sudden health deterioration. The most significant hospital admission for children in winter is a visible scenario in the local clinics or hospitals each year. This colder season is relatively shorter in Bangladesh but causes enormous suffering for children and older adults. In a report published by the Health Effect Institute (HEI) in 2020, a total of 174,000 deaths were reported due to air pollution in Bangladesh. Surprisingly, 20% were infant deaths due to air pollution in Bangladesh in 2019. A small tiny air particle with 2.5 mm in aerodynamic diameter (PM2.5) is the most concern in this health emergency for Bangladesh. PM2.5 is tiny enough to reach out very deep into the respiratory tract.
Such absorption of PM2.5 in children's airways results in from asthma, coughing, including many other pulmonary diseases. The air particles may get free enough to pass through the plasma membrane in the cell, blood-brain barrier, and placenta barrier for pregnant mothers. There are suspected causes of children's neurological defects or IQ loss, such as dementia linked to poor air quality in indoor living places or outdoor ambient conditions. These particles are externally or internally mixed with toxic metals and organic compounds emitted from various sources or causes; in a recent article from BCSIR in Dhaka by lead Dr. Mohammad Moniruzzaman, collaborating with Aerosol Lab at North South University on the absorption of toxic metals from the air on the human respiratory airways published in Chemosphere, a high-ranking journal in Elsevier.It clearly shows that the possible exposure to toxic metals is relatively high in the middle of the day. A significant portion of the metals in PM2.5 is absorbed in the lower respiratory tract, an important health concern for the people in Dhaka City. This country needs an immediate inventory of emission sources of air particles and related processes responsible for children's deleterious health damages. An urgent call may protect the children from this modern version of 'Silent spring'.
As a tropical country, the ozone level, a short-lived air pollutant, and a climate variable are relatively higher at the surface level over the tropospheric air in Bangladesh. Ozone has no sources that are responsible for its high concentration. However, regional warming is fully accountable for this photochemically generated gas in the air. Ozone is more harmful to rural people as its concentration is relatively higher in those remote parts than in urban areas. In the rural region, ozone interaction with health and agriculture farming, vegetation, and plantation is very well reported. It is a very reactive short live molecule but can cause several respiratory diseases among children. It interrupts the growth of the plants or vegetation, which links to crop production yield. In our farming, a considerable effect may cause rice and wheat production. Several other atmospheric compositions also hamper fruit production and flowering in the trees. Mangoes and other seasonal fruits may get influenced by bad air quality. It links to the flowering of the trees for fruits and vegetables. For example, mangoes are popular seasonal fruits in Bangladesh. A large population in the western region of Bangladesh cultivates mangos and adds nutritional value to children and other aged groups of people. These seasonal fruits are an economic driver for a large group in our population. Thus, Bangladesh needs an economically sensitive air quality guideline that the local bodies still need to introduce. DoE may take it to the discussion table to see if there is any benefit to limiting the responsible gases in the air. An ecologically sensitive air quality guideline will produce economic benefits and prosperous life among the farmers in this country.
(The writer is Associate Professor and Leader of the Aerosol Lab, Department of Environmental Science and Management at North South University).