Largest skin cancer screening (multiple location)

According to Official Guinness Records,

The largest simultaneous skin cancer screening involved 34,435 participants at 170 different locations across Brazil, for an event organised by the Brazilian Society of Dermatology for the Skin Cancer Prevention National Campaign, on 5 December, 2009.
This was the 11th year of the campaign and it has been seen to grown every year.

For a complete list of 2009 records, please visit 2009 Guinness Records in Brazil.

Related Images

Other Brazil records that might interest you:

• Largest collection of cachaça bottles
• Longest time breath held voluntarily (female)
• Largest punch bag
• Fastest time to scan and bag 50 shopping items
• Longest police stand-off with a videogame peripheral