MEXICO CITY (Reuters) - Chronic pollution in Mexico City, which stains the sky yellow and can trigger government warnings to stay indoors, could be killing off residents' sense of smell, scientists say.
Tests showed people in Mexico City -- a sprawling metropolis crammed with around 20 million people and 4 million cars -- struggled to sniff out everyday odors like coffee and orange juice compared to residents of a nearby town.
Their noses are so badly damaged from a life inhaling toxic particles that they also find it harder to detect the scent of rotten food, said researcher Robyn Hudson who ran the study.
"We added a substance (to powdered milk) that is a common contaminant of food, something that smells disgusting basically -- like a sour, rotting cabbage," said Hudson. "We were able to see at what point ... they would start to reject the contaminated sample, say 'ew yuck! no! take it away please,'" said Hudson, an Australian and a senior research scientist at Mexico's National Autonomous University (UNAM).
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http://www.enn.com/pollution/article/37315