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Understanding The Pollutants That Influence Your Outdoor Air

Air pollution is one of the biggest challenges in the urban world. Everyday new studies are being conducted about how the deteriorating air quality is damaging our health and environment. Particulate pollution is now known to decrease our average life span, increase the risk of respiratory diseases, induce cardiovascular diseases, affect our reproductive organs and even affect the health of babies still in the womb.

Man-made sources such as emissions from factories, traffic related air pollution (TRAP) and construction dust commonly contribute to poor AQI (Air Quality Index). But there are other natural sources that add to or stimulate ambient air pollution levels - smoke from wildfires, volcanic eruptions, earthquakes, wind patterns, pollen or biogenic carbon emissions.

Common Air Pollutants

Various sources add various types of pollutants into the outdoor air. While some are manageable, others are lethally harmful to the human bodies as well as the environment.

Particulate matter (PM10 and PM2.5) - Also known as "particle pollution" or "PM" refers to very minute solid and liquid droplets suspended in the atmosphere such as nitrates, sulphates, organic compounds, metals, soil or dust particles and allergens (pollen, mold).

To give you an idea of the size, the diameter of an average human hair is 50 to 70 microns or micrometer. Whereas, PM10 has a diameter of 10 microns/micrometres or less, making them tiny enough to easily get into our respiratory tract through the nose or mouth and cause blockage in the functioning of lungs and heart. Meanwhile, PM2.5 has a diameter of 2.5 microns/micrometres or less. These particles are even smaller and can penetrate through the lung membrane entering into our bloodstream making it a greater health hazard.

Ozone (O3) - Ground level ozone is a main component of smog, which is why a smog blanket in the sky is dangerous to our health. O3 is created when sunlight interacts with emissions from sources like motor vehicles and industries. It can spread wide and build up higher concentrations from the initial polluting sources. Even at low concentrations, ground-level ozone can cause chest pains, lung inflammation, asthma attacks, throat irritation and prolonged exposure can permanently scar lung tissue.

Nitrogen dioxide (NO2) - Nitrogen dioxide is a highly reactive gas that is created by emissions from combustion activities, commercial manufacturing, motor vehicles, power plants, welding, explosives etc. Exposure to NO2 can cause respiratory infections and chronic lung diseases.

Carbon monoxide (CO) - Carbon monoxide is an odourless, colourless gas which forms when the carbon in fuels doesn’t entirely burn. It is mostly produced by industrial activities and motor vehicles but it can also naturally occur from forest fires. Carbon monoxide levels are typically highest during winter, because cold weather slows down combustion and traps pollutants close to the ground.

Sulphur dioxide (SO2) - Sulphur dioxide is a gas with a strong, unpleasant odour that is extremely reactive. It is commonly formed during fossil fuel combustion at power plants, petroleum refineries, metal processing or smelting activities. Volcanic eruptions or decomposition of organic waste also generate sulphur gases naturally. Exposure to SO2 can cause eye irritation, respiratory tract infection and secretion of mucus triggering asthma or chronic bronchitis.

Outdoor Air Pollution affects your home air

Most of us prefer to allow natural sunlight and fresh air from outside into our homes. But with the growing air pollution, this fresh oxygen also brings in toxic gases, particulate matter and allergens into our indoor spaces. Since we spend most of our time indoors, homes, offices, schools, filtration of air is now a necessity for our health. Indoor air already has various sources like gas stoves, heating/cooling appliances, damp walls, paint, cleaning chemicals, that add to household pollution. In such situations, air quality tests help analyse what is making your indoor air unhealthy and implement the right solutions.

Government Policies on Ambient Air Pollution

Since the biggest contributors are sources such as industries, traffic and construction, government intervention is very important. The Central Pollution Control Board (CPCB) in India has been working on monitoring and regulating air pollution, however, it’s still a long battle. Both public and private sectors need to join hands in introducing and funding innovative and effective measures to guarantee cleaner air. Bettering public transport systems in terms of availability, hygiene and safety will encourage people to reject private vehicles reducing road traffic. Buildings should be reoriented in order to adopt cleaner technologies instead of fossil powered generators, use energy-efficient lighting, heating and cooling facilities. Construction activities must be regulated to control dust pollution, as well as green construction policies should be promoted to reduce carbon emissions from the built environment.

Air pollution is reducing our life span by years. Even though there isn’t much we can do as individuals to fix the ambient air pollution, indoor air quality of our homes is still in our control. Improving the IAQ today can give us and our loved ones several healthier tomorrows to look forward to.


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