Taken from an interview on the Health Talk FM.102 program, Happy & Healthy, airing every Saturday from 9:00 a.m. to 10:00 a.m. - "Toxic Air Pollution in Bangkok"

Escalating Presence of Toxic Dust in Bangkok

The prevalence of toxic dust in Bangkok is steadily increasing, prompting heightened awareness among individuals regarding the perils of air pollution. Concerns about the detrimental effects of pollution on personal well-being and the health of their children have become paramount. Particularly in numerous areas, the concentration of PM 2.5 dust particles surpasses acceptable levels, necessitating the avoidance of outdoor activities and the consistent use of masks as a preventive measure against dust.

                      Bangkok, like many other areas, routinely experiences the presence of toxic dust on a daily basis. However, the current situation has become more pronounced. This is particularly noticeable during the months of December, January, and February, which are characterized by stable weather conditions and minimal wind activity. Such conditions, often referred to as 'closed air,' exacerbate the visibility of dust particles. The economic zones, marked by extensive construction activities, are particularly affected. The dust we encounter is not limited to hazardous PM 2.5 particles; there is also the presence of PM 10 dust, resulting from various construction works that converge when the air is stagnant. Consequently, the dust particles settle and become easier to inhale, resembling mist or smoke. However, when the air is open and wind is present, these dust particles tend to disperse and diminish.

                    First and foremost, let's familiarize ourselves with the term PM, which stands for Particulate Matter. Specifically, PM refers to particulate matter measuring 2.5 microns in size, commonly known as PM 2.5 dust. The World Health Organization has officially classified PM 2.5 dust as a group of carcinogens. Despite being invisible to the naked eye, PM 2.5 contains various harmful toxins, including ozone gas, nitrogen dioxide, carbon monoxide, sulfur dioxide, arsenic, and lead. These pollutants are present in the air we breathe and can be inhaled. They originate from sources such as vehicle emissions, particularly from diesel-powered vehicles that do not burn fuel completely. Other contributors include dust from crushed tires on asphalt roads, incineration processes like open burning and power generation that release sulfur dioxide and nitrogen gas, as well as industrial activities in places like the Rayong industrial zone, which may introduce mercury and arsenic into the air.

                    When we breathe in through our noses, larger dust particles are usually trapped by our nose hairs, leading to a mucus membrane reaction or the production of nasal mucus. However, if the dust particles are smaller than our nose hairs, they can pass through the nasal cavity, down the larynx, and into the throat, eventually reaching the larger bronchi. At the trachea, there are small, waving hairs called cilia that help expel foreign particles as sputum or may cause symptoms like a cold or sore throat, often diagnosed as an infection. This mucus can also be coughed up and expelled. However, smaller dust particles can travel further down into the bronchioles, the sub-trachea, and eventually settle in the alveoli, which are small air sacs in the lungs. This is a critical point of concern because the alveoli are surrounded by blood vessels. Consequently, the dust particles can enter our bloodstream. When this occurs, our body triggers an inflammatory response that can lead to acute or chronic diseases, particularly if the dust reaches organs such as the heart, brain, or blood vessels. It's important to note that individuals with a healthy body are generally less susceptible to these diseases.

                While immediate disease may not result from dust exposure, short-term effects can occur, particularly for individuals with allergies or sensitivities. Once dust particles enter the nasal passages, they can trigger symptoms such as rhinitis, allergies, asthma, persistent coughing, and conjunctivitis. These symptoms can often be managed in the short term. However, in the long term, daily exposure to dust can lead to its accumulation within the body. While this accumulation may not pose a significant problem for healthy individuals, it can be more concerning for young children in their developmental stages, older individuals with pre-existing conditions like heart disease, diabetes, or high blood pressure, and those with compromised health. In such cases, more severe diseases may arise.

                In situations where avoiding dusty environments is not feasible, preventive measures must be taken. Wearing a dust mask is highly recommended. Individuals should also aim to reach indoor environments quickly to minimize exposure. Refraining from outdoor exercise during periods when dust levels exceed acceptable standards is crucial. Individuals who work outdoors, such as traffic police officers, street vendors, or officials in Bangkok, are advised to wear an N95 mask for their safety. The N95 mask is capable of filtering dust particles as small as 0.3 microns and provides coverage from the nose to under the chin, forming a semi-circular seal on the face. It is important to wear the N95 mask correctly, which involves breathing through the nose and exhaling through the mouth. Normal green masks may not provide adequate filtration, but masks labeled "Extra" with an additional layer of filtration are recommended. (Green masks can filter particles up to 10 microns, suitable for filtering construction or regular dust but not PM 2.5 particles.)

                By being aware of the dangers posed by PM 2.5 dust and taking precautions like wearing masks, avoiding outdoor exercise, and minimizing time spent in heavily polluted areas, we can reduce the risk of serious diseases. It is advisable to monitor and refer to the Air Quality Index (AQI) to assess the level of air quality, categorized into five levels (blue, green, yellow, orange, and red) based on their impact on health. Nonetheless, it is important to continue living a normal life while prioritizing protective measures to mitigate the risk of various severe diseases.

by Dr. Kanda Kumueang, M.D.

Medical Examination Department Doctor Trained in Occupational Medicine