{"id":30383,"date":"2026-09-26T17:59:00","date_gmt":"2026-09-26T12:29:00","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=30383"},"modified":"2026-09-26T17:59:00","modified_gmt":"2026-09-26T12:29:00","slug":"national-air-quality-index","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/national-air-quality-index\/","title":{"rendered":"National Air Quality Index (NAQI), Meaning, Objectives, Parameters"},"content":{"rendered":"<p><b>National Air Quality Index (NAQI)<\/b><span style=\"font-weight: 400\"> is a tool that reports daily air quality by converting complex pollutant data into a single value, category, and colour code, highlighting potential health effects from polluted air. AQI helps compare air quality across locations, track improvements or deterioration, and raise public awareness, especially for vulnerable groups.<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">In India, the <\/span><b>Central<\/b> <b>Pollution<\/b> <b>Control<\/b> <b>Board<\/b> <b>(CPCB)<\/b><span style=\"font-weight: 400\"> issues the AQI and covers pollutants like PM10, PM2.5, NO\u2082, SO\u2082, CO, O\u2083, NH\u2083, and Pb. WHO provides global guidelines, setting strict limits for pollutants such as PM2.5 and PM10 to protect health and guide cleaner air policies.<\/span><\/p>\r\n<h2><span style=\"font-weight: 400\">National Air Quality Index (NAQI) Meaning<\/span><\/h2>\r\n<p><b>National Air Quality Index (NAQI)<\/b> <b>was launched in<\/b><span style=\"font-weight: 400\"> 2014 to make air-quality information simple, accessible and understandable to the general public. It follows the principle of \u201cOne Number-One Colour-One Description\u201d, converting complex data on air pollutants into a single index value with a corresponding category and colour code.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Daily reporting:<\/b><span style=\"font-weight: 400\"> Provides a simplified assessment of the daily ambient air quality.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Pollution status:<\/b><span style=\"font-weight: 400\"> Indicates whether the air is clean or polluted and conveys the associated health risks.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Health-oriented:<\/b><span style=\"font-weight: 400\"> Primarily reflects short-term health effects that may arise from exposure to polluted air over a few hours or days.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Simple communication:<\/b><span style=\"font-weight: 400\"> Presents complex pollutant information in an easily understandable form, enabling citizens to assess air quality at a glance.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">National Air Quality Index (NAQI) Objectives<\/span><\/h2>\r\n<p><b>National Air Quality Index (NAQI)<\/b><span style=\"font-weight: 400\"> aims to improve understanding and management of air quality by providing clear information for public awareness, comparison, and informed action.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Comparison: <\/b><span style=\"font-weight: 400\">Facilitates comparison of air-quality conditions across different cities and locations.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Trend monitoring: <\/b><span style=\"font-weight: 400\">Tracks improvements or deterioration in air quality over time.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Monitoring gaps: <\/b><span style=\"font-weight: 400\">Helps identify deficiencies in air-quality standards and gaps in monitoring systems.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Public awareness:<\/b><span style=\"font-weight: 400\"> Keeps citizens informed about <\/span><strong><a href=\"https:\/\/vajiramandravi.com\/upsc-exam\/environment\/\" target=\"_blank\">environment<\/a><\/strong><span style=\"font-weight: 400\">\u00a0conditions and enables vulnerable groups to take appropriate precautions.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">National Air Quality Index (NAQI) Issuing Authority<\/span><\/h2>\r\n<p><b>The National Air Quality Index India<\/b><span style=\"font-weight: 400\"> is released by the<\/span><b> Central Pollution Control Board (CPCB) <\/b><span style=\"font-weight: 400\">under the Ministry of Environment, Forest and Climate Change (MoEFCC). CPCB is responsible for monitoring and disseminating ambient air-quality information across India.<\/span><\/p>\r\n<h2><span style=\"font-weight: 400\">National Air Quality Index Map<\/span><\/h2>\r\n<p><b>The National Air Quality Index Map<\/b><span style=\"font-weight: 400\"> provides a visual representation of air-quality conditions across different cities and monitoring locations in India, using <\/span><b>National Air Quality Index <\/b><span style=\"font-weight: 400\">values and colour-coded categories to indicate pollution levels.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Spatial comparison:<\/b><span style=\"font-weight: 400\"> Enables quick comparison of air-quality conditions across different locations.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Pollution hotspots:<\/b><span style=\"font-weight: 400\"> Helps identify areas experiencing poor, very poor or severe air quality.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Public awareness:<\/b><span style=\"font-weight: 400\"> Makes regional variations in air pollution easier for citizens and authorities to understand.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">National Air Quality Index Measuring Parameters<\/span><\/h2>\r\n<p><b>The India National Air Quality Index <\/b><span style=\"font-weight: 400\">measures ambient air quality using eight key pollutants and converts their concentrations into individual sub-indices; the highest sub-index determines the overall AQI for a monitoring location.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>National Air Quality Index Pollutants: National Air Quality Index <\/b><span style=\"font-weight: 400\">considers eight major air pollutants for assessing ambient air quality:<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Particulate Matter:<\/b><span style=\"font-weight: 400\"> PM\u2081\u2080 and PM\u2082.\u2085<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Gases:<\/b><span style=\"font-weight: 400\"> NO\u2082, SO\u2082, CO, O\u2083 and NH\u2083<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Heavy metal:<\/b><span style=\"font-weight: 400\"> Lead (Pb)<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li style=\"font-weight: 400\"><b>Averaging period:<\/b><span style=\"font-weight: 400\"> Uses 24-hour average concentrations for most pollutants, while CO and O\u2083 are assessed using an 8-hour average.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Data requirement:<\/b><span style=\"font-weight: 400\"> A minimum of 16 hours of data is required to calculate a pollutant sub-index.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Overall Air Quality Index:<\/b><span style=\"font-weight: 400\"> Requires data for at least three pollutants, with PM\u2082.\u2085 or PM\u2081\u2080 being one of them; otherwise, the overall <\/span><b>Air Quality Index <\/b><span style=\"font-weight: 400\">is considered insufficient.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Location-specific monitoring:<\/b><span style=\"font-weight: 400\"> All eight pollutants are not necessarily monitored at every location, depending on the monitoring network.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Pollutant-wise assessment:<\/b><span style=\"font-weight: 400\"> Individual sub-indices can be calculated and reported even when an overall AQI cannot be determined.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Continuous monitoring:<\/b><span style=\"font-weight: 400\"> Automated monitoring stations generate real-time AQI using running-average values, reducing the need for manual intervention.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Manual monitoring:<\/b><span style=\"font-weight: 400\"> An AQI calculator is available for manually monitored stations to calculate the index from observed pollutant concentrations.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">National Ambient Air Quality Standards (NAAQS)<\/span><\/h2>\r\n<p><b>National Ambient Air Quality Standards (NAAQS)<\/b><span style=\"font-weight: 400\"> specify permissible concentration levels of air pollutants in <\/span><b>ambient (outdoor) air<\/b><span style=\"font-weight: 400\"> to protect public health and the environment.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Legal basis:<\/b><span style=\"font-weight: 400\"> The standards are prescribed under the <a href=\"https:\/\/vajiramandravi.com\/current-affairs\/air-prevention-and-control-of-pollution-act-1981\/\" target=\"_blank\"><strong>Air (Prevention and Control of Pollution) Act, 1981<\/strong><\/a>.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Prescribed by:<\/b> <b>Central Pollution Control Board (CPCB)<\/b><span style=\"font-weight: 400\">.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Coverage:<\/b><span style=\"font-weight: 400\"> The revised NAAQS, notified in 2009, cover 12 pollutants.<\/span><\/li>\r\n<\/ul>\r\n<p><img decoding=\"async\" class=\"wp-image-30387 aligncenter\" src=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/09\/26121207\/WhatsApp-Image-2026-09-26-at-12.11.09-PM.jpeg\" alt=\"National Ambient Air Quality Standards\" width=\"559\" height=\"527\" srcset=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/09\/26121207\/WhatsApp-Image-2026-09-26-at-12.11.09-PM.jpeg 1600w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/09\/26121207\/WhatsApp-Image-2026-09-26-at-12.11.09-PM-768x724.jpeg 768w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/09\/26121207\/WhatsApp-Image-2026-09-26-at-12.11.09-PM-1536x1448.jpeg 1536w\" sizes=\"(max-width: 559px) 100vw, 559px\" \/><\/p>\r\n<h2><span style=\"font-weight: 400\">National Air Quality Index (NAQI) Categories<\/span><\/h2>\r\n<p><b>National Air Quality Index India<\/b><span style=\"font-weight: 400\"> classifies air quality into six categories based on the AQI value:<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Good (0\u201350):<\/b><span style=\"font-weight: 400\"> Air quality poses minimal or no health risk.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Satisfactory (51-100):<\/b><span style=\"font-weight: 400\"> May cause slight breathing discomfort in sensitive individuals.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Moderately Polluted (101-200): <\/b><span style=\"font-weight: 400\">Can trigger breathing difficulties in people with lung conditions like asthma, and cause discomfort for those with heart disease, children, and the elderly.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Poor (201-300): <\/b><span style=\"font-weight: 400\">Prolonged exposure may lead to breathing issues and discomfort for people with heart conditions.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Very Poor (301-400):<\/b><span style=\"font-weight: 400\"> Can cause respiratory illnesses with prolonged exposure; effects are stronger for individuals with lung or heart diseases.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Severe (401-500): <\/b><span style=\"font-weight: 400\">May cause respiratory problems even in healthy individuals and serious health risks for those with lung or heart conditions; difficulties may occur during light physical activity.<\/span><\/li>\r\n<\/ul>\r\n<p><img decoding=\"async\" class=\"wp-image-30385 aligncenter\" src=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/09\/26115958\/1544612065737.png\" alt=\"National Air Quality Index (NAQI) Categories\" width=\"680\" height=\"350\" srcset=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/09\/26115958\/1544612065737.png 865w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/09\/26115958\/1544612065737-768x395.png 768w\" sizes=\"(max-width: 680px) 100vw, 680px\" \/><\/p>\r\n<h2><span style=\"font-weight: 400\">WHO Air Quality Guidelines<\/span><\/h2>\r\n<p><b>National Air Quality Index India<\/b><span style=\"font-weight: 400\"> can be compared with the <\/span><strong><a href=\"https:\/\/vajiramandravi.com\/upsc-exam\/world-health-organisation\/\" target=\"_blank\">World Health Organisation (WHO)<\/a><\/strong><b> Air Quality Guidelines (AQGs)<\/b><span style=\"font-weight: 400\">, which provide health-based recommendations for major air pollutants and serve as a reference for policymakers in managing ambient air pollution.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The WHO Air Quality Guidelines (AQGs) <\/span><b>PM2.5<\/b><span style=\"font-weight: 400\"> recommendations:<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>PM2.5:<\/b><span style=\"font-weight: 400\"> 5\u202f\u00b5g\/m\u00b3 annual mean and 15\u202f\u00b5g\/m\u00b3 24-hour mean.<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">To help areas with high pollution achieve cleaner air, the <\/span><b>WHO sets interim targets for PM2.5<\/b><span style=\"font-weight: 400\"> as step-by-step milestones, especially for cities and countries with severe air quality issues. These targets are:<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">35 \u00b5g\/m3 annual mean, 75 \u00b5g\/m3 24-hour mean.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">25 \u00b5g\/m3 annual mean, 50 \u00b5g\/m3 24-hour mean.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">15 \u00b5g\/m3 annual mean, 37.5 \u00b5g\/m3 24-hour mean.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">10 \u00b5g\/m3 annual mean, 25 \u00b5g\/m3 24-hour mean.<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">WHO recommended <\/span><b>guideline levels for other key pollutants:<\/b>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>PM10:<\/b><span style=\"font-weight: 400\"> 15\u202f\u00b5g\/m\u00b3 annual mean, 45\u202f\u00b5g\/m\u00b3 24-hour mean<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Ozone (O\u2083):<\/b><span style=\"font-weight: 400\"> 100\u202f\u00b5g\/m\u00b3 8-hour mean<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Nitrogen Dioxide (NO\u2082):<\/b><span style=\"font-weight: 400\"> 10\u202f\u00b5g\/m\u00b3 annual average, 25\u202f\u00b5g\/m\u00b3 24-hour mean<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Sulphur Dioxide (SO\u2082):<\/b><span style=\"font-weight: 400\"> 40\u202f\u00b5g\/m\u00b3 24-hour mean<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Carbon Monoxide (CO):<\/b><span style=\"font-weight: 400\"> 7\u202f\u00b5g\/m\u00b3 24-hour mean<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">National Air Quality Index (NAQI) UPSC PYQs<\/span><\/h2>\r\n<p><b>Q1: <\/b><span style=\"font-weight: 400\">Describe the key points of the revised Global Air Quality Guidelines (AQGs) recently released by the World Health Organisation (WHO). How are these different from its last update in 2005? What changes in India\u2019s <a href=\"https:\/\/vajiramandravi.com\/upsc-exam\/national-clean-air-programme\/\" target=\"_blank\"><strong>National Clean Air Programme<\/strong><\/a> are required to achieve revised standards? <\/span><b>(UPSC Mains 2021)<\/b><\/p>\r\n<p><b>Q2: <\/b><span style=\"font-weight: 400\">Consider the following statements regarding mercury pollution: <b>(UPSC Prelims 2023)<\/b><\/span><\/p>\r\n<ol>\r\n\t<li><span style=\"font-weight: 400\"> Gold mining activity is a source of mercury pollution in the world.<\/span><\/li>\r\n\t<li><span style=\"font-weight: 400\"> Coal-based thermal power plants cause mercury pollution.<\/span><\/li>\r\n\t<li><span style=\"font-weight: 400\"> There is no known safe level of exposure to mercury.<\/span><\/li>\r\n<\/ol>\r\n<p><span style=\"font-weight: 400\">How many of the above statements are correct?<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">(a) Only one<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">(b) Only two<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">(c) All three<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">(d) None<\/span><\/p>\r\n<p><b>Ans: (b)<\/b><\/p>\r\n<p><b>Q3:<\/b><span style=\"font-weight: 400\">\u00a0In the context of WHO Air Quality Guidelines, consider the following statements: <b>(UPSC Prelims 2022)<\/b><\/span><\/p>\r\n<ol>\r\n\t<li><span style=\"font-weight: 400\"> The 24-hour mean of PM2.5 should not exceed 15 \u00b5g\/m3 and annual mean of PM2.5 should not exceed 5 \u00b5g\/m3.<\/span><\/li>\r\n\t<li><span style=\"font-weight: 400\"> In a year, the highest levels of ozone pollution occur during the periods of inclement weather.<\/span><\/li>\r\n\t<li><span style=\"font-weight: 400\"> PM10 can penetrate the lung barrier and enter the bloodstream.<\/span><\/li>\r\n\t<li><span style=\"font-weight: 400\"> Excessive ozone in the air can trigger asthma.<\/span><\/li>\r\n<\/ol>\r\n<p><span style=\"font-weight: 400\">Which of the statements given above are correct?\u00a0<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">a) 1, 3 and 4<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">b) 1 and 4 only<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">c) 2, 3 and 4<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">a) 1 and 2 only<\/span><\/p>\r\n<p><b>Ans: (b)<\/b><\/p>","protected":false},"excerpt":{"rendered":"<p>National Air Quality Index (NAQI) converts complex air-quality data from eight pollutants into a single index value, category, and colour code. Check more about meaning, objectives &#038; parameters.<\/p>\n","protected":false},"author":22,"featured_media":30425,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[38,33],"tags":[2073,40,654],"class_list":["post-30383","post","type-post","status-publish","format-standard","has-post-thumbnail","category-upsc-notes","category-upsc-environment-ecology-notes","tag-national-air-quality-index","tag-quest","tag-upsc-environment-and-ecology-notes"],"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/30383","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=30383"}],"version-history":[{"count":5,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/30383\/revisions"}],"predecessor-version":[{"id":30431,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/30383\/revisions\/30431"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/30425"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=30383"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=30383"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=30383"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}