Today I learned

[timelets]

How to wash vegetables:

To get rid of pesticide residue and microbes like bacteria on vegetables, you should always wash them well before consumption.

Generally, a 30-second rinse followed by a 15-minute soak, and a final rinse will help to remove a significant portion of pesticide residue, said the Agri-Food and Veterinary Authority of Singapore (AVA).
http://www.straitstimes.com/singapore/health/the-st-guide-to-washing-fruits-and-vegetables