CrowdScience listener Namrata and presenter Chhavi Sachdev have something in common. They both get more tanned in the summer in the United States than back home in India. Namrata wants to know why she came back from her run in Boston with such a deep tan and doesn’t have the same experience in India. She’s got quite a few theories herself and wonders if it’s to do with the angle of the sun, pollution or humidity.

Chhavi talks to dermatologist Neelam Vashi, who’s based in Boston, to find out how we tan and what protects us from the sun.

She meets Julian Groebner at the World Radiation Centre in Switzerland who compares the data in India and the United States for CrowdScience and comes up with a surprising answer.

She also talks to Indians in Mumbai who share their attitudes to tanning and what steps they take to protect themselves from the heat of the sun.

Presenter Chhavi Sachdev

Producer Jo Glanville

Editor Ben Motley

(Photo: Woman sunbathing on sun lounger by swimming pool. Credit: IndiaPix/Getty Images)