{"id":91972,"date":"2025-06-01T11:10:24","date_gmt":"2025-06-01T11:10:24","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=91972"},"modified":"2025-06-01T11:10:24","modified_gmt":"2025-06-01T11:10:24","slug":"in-the-context-of-who-air-quality-guidelines-consider-the-following-s","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/","title":{"rendered":"In the context of WHO Air Quality Guidelines, consider the following s"},"content":{"rendered":"<p>In the context of WHO Air Quality Guidelines, consider the following statements :<\/p>\n<ul>\n<li>The 24-hour mean of PM$_{2.5}$ should not exceed 15 $\\mu$g\/m$^3$ and annual mean of PM$_{2.5}$ should not exceed 5 $\\mu$g\/m$^3$.<\/li>\n<li>In a year, the highest levels of ozone pollution occur during the periods of inclement weather.<\/li>\n<li>PM$_{10}$ can penetrate the lung barrier and enter the bloodstream.<\/li>\n<li>Excessive ozone in the air can trigger asthma.<\/li>\n<\/ul>\n<p>Which of the statements given above are correct ?<\/p>\n<p>[amp_mcq option1=&#8221;1, 3 and 4&#8243; option2=&#8221;1 and 4 only&#8221; option3=&#8221;2, 3 and 4&#8243; option4=&#8221;1 and 2 only&#8221; correct=&#8221;option2&#8243;]<\/p>\n<div class=\"psc-box-pyq-exam-year-detail\">\n<div class=\"pyq-exam\">\n<div class=\"psc-heading\">This question was previously asked in<\/div>\n<div class=\"psc-title line-ellipsis\">UPSC IAS &#8211; 2022<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-ias-2022.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-ias-2022\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nThe correct option is B, as statements 1 and 4 are correct.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\nStatement 1 is correct. The 2021 WHO Air Quality Guidelines recommend a 24-hour mean of PM$_{2.5}$ not exceeding 15 $\\mu$g\/m$^3$ and an annual mean not exceeding 5 $\\mu$g\/m$^3$.<br \/>\nStatement 2 is incorrect. Ground-level ozone is formed through photochemical reactions involving sunlight, NOx, and VOCs. High concentrations typically occur during hot, sunny weather with stagnant air, not during inclement weather which tends to break down or disperse pollutants.<br \/>\nStatement 3 is incorrect. While both PM$_{10}$ and PM$_{2.5}$ are harmful, smaller particles pose a greater health risk because they can penetrate deeper. PM$_{2.5}$ can reach the deep lung tissue and even enter the bloodstream. PM$_{10}$ mainly deposits in the upper respiratory tract and larger airways; crossing the lung barrier into the bloodstream is less characteristic of PM$_{10}$ as a whole compared to PM$_{2.5}$ and ultrafine particles.<br \/>\nStatement 4 is correct. Excessive exposure to ground-level ozone is a known respiratory irritant and can trigger or worsen asthma symptoms, causing coughing, wheezing, and difficulty breathing.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nThe WHO guidelines provide evidence-based recommendations for air quality levels to protect public health. Many countries have national air quality standards, which may differ from the WHO guidelines.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>In the context of WHO Air Quality Guidelines, consider the following statements : The 24-hour mean of PM$_{2.5}$ should not exceed 15 $\\mu$g\/m$^3$ and annual mean of PM$_{2.5}$ should not exceed 5 $\\mu$g\/m$^3$. In a year, the highest levels of ozone pollution occur during the periods of inclement weather. PM$_{10}$ can penetrate the lung barrier &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"In the context of WHO Air Quality Guidelines, consider the following s\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/#more-91972\">Detailed Solution<span class=\"screen-reader-text\">In the context of WHO Air Quality Guidelines, consider the following s<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1092],"tags":[1108,1136,1137],"class_list":["post-91972","post","type-post","status-publish","format-standard","hentry","category-upsc-ias","tag-1108","tag-environment-and-ecology","tag-pollution","no-featured-image-padding"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v22.2 (Yoast SEO v23.3) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>In the context of WHO Air Quality Guidelines, consider the following s<\/title>\n<meta name=\"description\" content=\"The correct option is B, as statements 1 and 4 are correct. Statement 1 is correct. The 2021 WHO Air Quality Guidelines recommend a 24-hour mean of PM$_{2.5}$ not exceeding 15 $mu$g\/m$^3$ and an annual mean not exceeding 5 $mu$g\/m$^3$. Statement 2 is incorrect. Ground-level ozone is formed through photochemical reactions involving sunlight, NOx, and VOCs. High concentrations typically occur during hot, sunny weather with stagnant air, not during inclement weather which tends to break down or disperse pollutants. Statement 3 is incorrect. While both PM$_{10}$ and PM$_{2.5}$ are harmful, smaller particles pose a greater health risk because they can penetrate deeper. PM$_{2.5}$ can reach the deep lung tissue and even enter the bloodstream. PM$_{10}$ mainly deposits in the upper respiratory tract and larger airways; crossing the lung barrier into the bloodstream is less characteristic of PM$_{10}$ as a whole compared to PM$_{2.5}$ and ultrafine particles. Statement 4 is correct. Excessive exposure to ground-level ozone is a known respiratory irritant and can trigger or worsen asthma symptoms, causing coughing, wheezing, and difficulty breathing.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"In the context of WHO Air Quality Guidelines, consider the following s\" \/>\n<meta property=\"og:description\" content=\"The correct option is B, as statements 1 and 4 are correct. Statement 1 is correct. The 2021 WHO Air Quality Guidelines recommend a 24-hour mean of PM$_{2.5}$ not exceeding 15 $mu$g\/m$^3$ and an annual mean not exceeding 5 $mu$g\/m$^3$. Statement 2 is incorrect. Ground-level ozone is formed through photochemical reactions involving sunlight, NOx, and VOCs. High concentrations typically occur during hot, sunny weather with stagnant air, not during inclement weather which tends to break down or disperse pollutants. Statement 3 is incorrect. While both PM$_{10}$ and PM$_{2.5}$ are harmful, smaller particles pose a greater health risk because they can penetrate deeper. PM$_{2.5}$ can reach the deep lung tissue and even enter the bloodstream. PM$_{10}$ mainly deposits in the upper respiratory tract and larger airways; crossing the lung barrier into the bloodstream is less characteristic of PM$_{10}$ as a whole compared to PM$_{2.5}$ and ultrafine particles. Statement 4 is correct. Excessive exposure to ground-level ozone is a known respiratory irritant and can trigger or worsen asthma symptoms, causing coughing, wheezing, and difficulty breathing.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T11:10:24+00:00\" \/>\n<meta name=\"author\" content=\"rawan239\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rawan239\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"In the context of WHO Air Quality Guidelines, consider the following s","description":"The correct option is B, as statements 1 and 4 are correct. Statement 1 is correct. The 2021 WHO Air Quality Guidelines recommend a 24-hour mean of PM$_{2.5}$ not exceeding 15 $mu$g\/m$^3$ and an annual mean not exceeding 5 $mu$g\/m$^3$. Statement 2 is incorrect. Ground-level ozone is formed through photochemical reactions involving sunlight, NOx, and VOCs. High concentrations typically occur during hot, sunny weather with stagnant air, not during inclement weather which tends to break down or disperse pollutants. Statement 3 is incorrect. While both PM$_{10}$ and PM$_{2.5}$ are harmful, smaller particles pose a greater health risk because they can penetrate deeper. PM$_{2.5}$ can reach the deep lung tissue and even enter the bloodstream. PM$_{10}$ mainly deposits in the upper respiratory tract and larger airways; crossing the lung barrier into the bloodstream is less characteristic of PM$_{10}$ as a whole compared to PM$_{2.5}$ and ultrafine particles. Statement 4 is correct. Excessive exposure to ground-level ozone is a known respiratory irritant and can trigger or worsen asthma symptoms, causing coughing, wheezing, and difficulty breathing.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/","og_locale":"en_US","og_type":"article","og_title":"In the context of WHO Air Quality Guidelines, consider the following s","og_description":"The correct option is B, as statements 1 and 4 are correct. Statement 1 is correct. The 2021 WHO Air Quality Guidelines recommend a 24-hour mean of PM$_{2.5}$ not exceeding 15 $mu$g\/m$^3$ and an annual mean not exceeding 5 $mu$g\/m$^3$. Statement 2 is incorrect. Ground-level ozone is formed through photochemical reactions involving sunlight, NOx, and VOCs. High concentrations typically occur during hot, sunny weather with stagnant air, not during inclement weather which tends to break down or disperse pollutants. Statement 3 is incorrect. While both PM$_{10}$ and PM$_{2.5}$ are harmful, smaller particles pose a greater health risk because they can penetrate deeper. PM$_{2.5}$ can reach the deep lung tissue and even enter the bloodstream. PM$_{10}$ mainly deposits in the upper respiratory tract and larger airways; crossing the lung barrier into the bloodstream is less characteristic of PM$_{10}$ as a whole compared to PM$_{2.5}$ and ultrafine particles. Statement 4 is correct. Excessive exposure to ground-level ozone is a known respiratory irritant and can trigger or worsen asthma symptoms, causing coughing, wheezing, and difficulty breathing.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T11:10:24+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/","url":"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/","name":"In the context of WHO Air Quality Guidelines, consider the following s","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T11:10:24+00:00","dateModified":"2025-06-01T11:10:24+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The correct option is B, as statements 1 and 4 are correct. Statement 1 is correct. The 2021 WHO Air Quality Guidelines recommend a 24-hour mean of PM$_{2.5}$ not exceeding 15 $\\mu$g\/m$^3$ and an annual mean not exceeding 5 $\\mu$g\/m$^3$. Statement 2 is incorrect. Ground-level ozone is formed through photochemical reactions involving sunlight, NOx, and VOCs. High concentrations typically occur during hot, sunny weather with stagnant air, not during inclement weather which tends to break down or disperse pollutants. Statement 3 is incorrect. While both PM$_{10}$ and PM$_{2.5}$ are harmful, smaller particles pose a greater health risk because they can penetrate deeper. PM$_{2.5}$ can reach the deep lung tissue and even enter the bloodstream. PM$_{10}$ mainly deposits in the upper respiratory tract and larger airways; crossing the lung barrier into the bloodstream is less characteristic of PM$_{10}$ as a whole compared to PM$_{2.5}$ and ultrafine particles. Statement 4 is correct. Excessive exposure to ground-level ozone is a known respiratory irritant and can trigger or worsen asthma symptoms, causing coughing, wheezing, and difficulty breathing.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/in-the-context-of-who-air-quality-guidelines-consider-the-following-s\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC IAS","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-ias\/"},{"@type":"ListItem","position":3,"name":"In the context of WHO Air Quality Guidelines, consider the following s"}]},{"@type":"WebSite","@id":"https:\/\/exam.pscnotes.com\/mcq\/#website","url":"https:\/\/exam.pscnotes.com\/mcq\/","name":"MCQ and Quiz for Exams","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/exam.pscnotes.com\/mcq\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209","name":"rawan239","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","caption":"rawan239"},"sameAs":["https:\/\/exam.pscnotes.com"],"url":"https:\/\/exam.pscnotes.com\/mcq\/author\/rawan239\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/91972","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/comments?post=91972"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/91972\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=91972"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=91972"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=91972"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}