Amazon Gold Rush

The Madeira river, a tributary of the Amazon, yields tons of gold each year. The garimpeiros or gold seekers extract it from the bottom of the river. However, mercury, a very poisonous chemical, is used to process the ore. Mercury vapour escapes to the atmosphere polluting the air and also contaminates fish in the river. Steps have been taken by big dredge owners to recycle the mercury to prevent it from escaping, but much more needs to be done. Hazards to the environment such as these will be discussed at the global Conference on the Environment and Development to be convened by the United Nations in Brazil in 1992.