On Sunday, thousands of people who participated in the half marathon had to run the 21-km stretch through a thick cover of smog.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/smog-hovers-over-capital-air-quality-plummets
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-standards
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-index-aqi
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rspm-pm-10
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/lung-disease
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution