Indians have reacted to US president Donald Trump describing the air in India, China and Russia as "filthy" during the final election debate.
His remarks drew both anger and introspection, with some Indians asking Prime Minister Narendra Modi to take notice.
Others agreed that capital Delhi's air was among the most foul in the world.
In recent weeks, the city's air quality has turned "severe", with residents complaining of breathing difficulties.
India's dreaded pollution season has returned as levels of PM2.5 - dangerous tiny pollutants in the air - in the capital have averaged around 180-300 micrograms per cubic metre in recent weeks, 12 times higher than the WHO's safe limits.
"Look at China, how filthy it is. Look at Russia. Look at India. It's filthy. The air is filthy. I walked out of the Paris Accord as we had to take out trillions of dollars and we were treated very unfairly," Mr Trump said talking about the decision to pull out of the Paris Climate Accord which aims to cap global warming "well below" 2C.
While his comments about China may not be strictly true, they have resonated with many in India.
The air in several cities in northern India is especially bad in winter months - November to February - when several factors, such as farmers burning crop stubble to clear their fields, vehicular and industrial pollution, festive fireworks and low wind speed, contribute to what doctors calls is a "deadly cocktail of poisonous gases". Despite the spikes in air pollution year after year, few concrete steps have been taken to control it.
On Friday morning, soon after Mr Trump's remarks, "filthy" and "Howdy! Modi" rose to the top of trends on Twitter.
The "Howdy, Modi!" event, held in Houston in September 2019 was attended by nearly 50,000 people. It was billed as one of the largest ever receptions for a foreign leader in the US and Mr Trump had called it a "profoundly historic event".
A senior leader of India's opposition Congress party, Kapil Sibal, asked if President Trump's remark on India's air was the "fruits of friendship" between the leaders of both the countries and a result of Howdy! Modi.
Many pointed to Mr Trump's visit to India in February this year when Mr Modi put on a grand show for his "good friend", complete with songs, dances and a mega reception at a cricket stadium.
Following the remarks, many tweeted screenshots of the Air Quality Index in Delhi which has risen to "severe" levels in parts of the city.
Writer Kiran Manral tweeted that "air reaches levels of toxicity every single year".
"Instead of getting all insulted and upset, can we just take it up as a challenge to clean up our surroundings and our air? So no one can ever dare say that again," she wrote.
The spike in the air quality in recent weeks is bad news for India's fight against coronavirus because several studies around the world have linked air pollution to higher Covid-19 case numbers and deaths.
And doctors and epidemiologists have warned that toxic air will only hamper India's fight against the virus.