Mongabay: Decades of oil extraction in the Western Amazon has caused widespread pollution, raising questions about the impact of a new oil boom in the region, according to a team of Spanish researchers presenting at a conference in California. Led by Antoni Rosell-Mele of the Universitat Autnoma de Barcelona, the team assembled a database of chemical analyses taken from 18 wastewater dumping sites from 10 different Amazon tributaries from 1983 to 2013. They looked at nine pollutants including lead, mercury...