The Ig Novel award 2013 for chemistry has been awarded to
"Shinsuke Imai, Nobuaki Tsuge, Muneaki Tomotake, Yoshiaki Nagatome, Hidehiko Kumgai (Japan) and Toshiyuki Nagata (Japan/Germany)"
for discovering that the biochemical process by which onions make people cry is even more complicated than scientists previously realized.
The award is based on a paper published in Nature in 2002 by these scientists. They studied the biochemistry of onion enzyme that works in a process producing compounds responsible for eye water.
More on Ig Nobel here.