Since 2009 researchers from Stanford University, working hand in hand with the Peruvian government and various Peruvian universities and NGO’s, have been studying the levels and effects of mercury in fish and people in the Puerto Maldonado, in the Amazon region of Peru, where artisanal gold mining is rife.

The basic findings to date according to the Carnegie Amazon Mercury Ecosystem Project (CAMEP) show: 

  • 60 percent of the species of fish sold in Puerto Maldonado had mercury levels that exceeded international mercury concentration limits for fish. Mercury levels of 9 of the 15 most consumed fish species had average levels of mercury above the international mercury reference limit (0.3 ppm) 
  • Mercury levels increased in 90 percent of fish species between 2009 and 2012.
  • 78 percent of adults in Puerto Maldonado had hair mercury concentrations above international mercury reference limits for human hair. More than three out of four adults analyzed in Puerto Maldonado had mercury concentrations higher than the reference limit.
  • The most vulnerable population, Women of Child Bearing Age, had the highest average mercury levels.
  • The human population of Puerto Maldonado has a very high risk of mercury exposure and associated heath effects due to high consumption of local contaminated fish, experience in gold mining, and from inhalation of airborne mercury from gold buying shops.

Mercury levels extremely high in areas of gold mining

Mercury levels extremely high in areas of gold mining