As we approach the winter season, it has become a habit to hear news about 'severe smog' situations in New Delhi. The current incident of smog occurring in the capital city of India, is just another example of how situation can go out of hand if proctive measures aren't taken soon. This is easier said than done. It will require a planned execution of preventive steps for a prolonged duration.
Having said that, we need to protect ourselves from the air pollution that spreads fast during such times. We also need a basic knowledge of the quality and types of pollutants around us so that we can take specific steps required to protect us from the particular pollutants.
Understanding Air Quality Index
Air Quality Index is one of the most common term used for checking air pollution. It’s a number defined by governments depending on the quality of air found in the region. The air quality is dependent on the quantity of few of the gases and components found in the air that includes Co2, S02, No2, Particulate Matter, Dust and suspended particles. The data also depends on the number of components one is including in the air quality measurement. A colour-indicated list is created that helps in estimating the level of the air quality.
Pollution Standards In India
In India, air is measured under the National Air Quality Monitoring Program (NAMP) that has installed 683 operating stations across 300 cities in 29 states and 6 union territories across India. The Indian government has included four major air pollutants in measuring the air quality, that includes Sulphur Dioxide (SO2), Oxides of Nitrogen as NO2, Respirable Suspended Particulate Matter (RSPM / PM10) and Fine Particulate Matter (PM2.5).
The Central Pollution Control Board (CPCB) under the Ministry of Environment, Forest and Climate Change monitors the current time data and displays it on its website. The average amount of various components in the air are categorised under industrial, rural, residential and other and ecologically sensitive areas. An area crossing limit of the listed amount of components is an indication of increase in the pollution in the particular area.
An average of 80 µg/m³ of SO2 and NO2, 100 µg/m³ of Particulate Matter (size less than 10 µg) and 60 µg/m³ of Particulate Matter (size less than 2.5 µg) is permissible and considered ‘satisfactory’ in Industrial, Residential and rural areas in India during an average day.
The current (12:07 pm) level of various pollutants in RK Puram, Delhi stands at Nitrogen Dioxide (NO2) 168.70 µg/m³, Sulphur Dioxide (SO2) 29.60 µg/m³, PM 2.5 616.97 µg/m³ and PM 10 at 973 µg/m³ on 9 November. The data taken from the CPCB website shows that the amount of one of the pollutants is more than nine times of its standard level.
The standard of the Indian pollution index is less stringent as compared to the level of permissible pollutants index issued by the World Health Organisation.
Prevention using Air purifiers and air masks
Air purifiers come in various sizes and varieties based on the places they are going to be used at and their capabilities. They can be installed at home, in the car or in office to filter out the access of few of these pollutants. Air purifiers available in the market vary in cost depending on the quality of the purification you are looking at, that further depends on the methods used by the air purifiers to clean the air.
Filter-based purifiers are the most common types of affordable purifiers available in the market. They contain High-efficiency particulate air (HEPA) filters that physically stop the particulate matter of varying size from entering from the filter. They are able to stop up-to 99 percent of the particles of 0.3 micro meter or above sizes. Then you have the the Activated carbon filters which use the principle of adsorption to be able to stop particles on a molecular level. These filters are often used with the HEPA filters to increase the purifying capability of the filters.
Thermodynamic sterilisation (TSS) method uses heat to purify the air. It uses a ceramic core that can be heated up to 200 degree Celsius, the air is passed through the heated core. The process kills microbiological particles including bacteria and viruses.
The third type of purifier uses ultraviolet particles to clean the germs present in air. This technology is also used in water purifiers.
The price of the purifiers varies based on their size and technology used to purify the air. It starts from as low as Rs 4,000-Rs 5000 and goes up to more than 1 Lakh rupees.
Air Masks are another option to protect oneself in the outdoor conditions. Air masks can be used while commuting or while one is exposed to a polluted area. The prices for air masks starts from Rs 100 and can go up to Rs 500 and more.
Air mask protect us from suspended air particles and particulate matter up to the size of 2.5 microns and above. Their usage is limited to some days and should be disposed off after their prescribed duration of usage. Some of these masks also include a layer of Activated carbon to filter the air.