Case Study on a World Level

Case Study 3 - World: Erosion in the Amazon Basin

The following case study demonstrates the secondary effect of soil erosion on human health. The case demonstrates how soil eroded from land brings with it undesirable chemicals to rivers where it contaminates fish that are consumed by humans.

Soil erosion is contributing to mercury contamination of rivers in the Amazon. In the Amazon, soil is rich in mercury primarily because of volcanic activity that deposited mercury rich dust onto the land. In particular, villagers living on the banks of the Tapajos River in central Brazil have been adversely affected by mercury through the fish they consume. Existing vegetation and forests are cleared through slashing and burning. Lack of good soil management practices in these agricultural lands has contributed to mercury rich soil being eroded into the Tapajos River. International agencies are working to educate villagers in their fish eating habit as well as implement management practices to reduce soil erosion.

Map of the Amazon River Basin.

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Thinking Question:

Much of the agriculture occurs along the bank of the Tapajos River. You are part of the international agencies working to educate villagers on soil erosion. Before you guide them with erosion control practices, you must first lay the foundation with information to establish the importance of soil. Describe the information about soil that you think is important for the villagers to know along the Tapajos River.