Consider the following statements regarding mercury pollution : 1. Gold mining activity is a source of mercury pollution in the world. 2. Coal-based thermal power plants cause mercury pollution. 3. There is no known safe level of exposure to mercury. How many of the above statements are correct?

All three statements are correct because artisanal gold mining is the largest global source of mercury, coal combustion releases significant mercury into the atmosphere, and the WHO states there is no known safe level of exposure due to its extreme toxicity. Option (b) is the most tempting wrong choice because candidates often confuse "permissible regulatory limits" with "safe biological levels," incorrectly assuming a safe threshold exists for heavy metals. This question tests the core concept of anthropogenic sources and health impacts of persistent pollutants, specifically in the context of the Minamata Convention.