How many polluted lakes are there in the world?

Estimating the exact number of polluted lakes worldwide is challenging due to varying definitions of pollution and differing assessment methods. However, studies indicate that millions of lakes are affected by pollution, particularly from agricultural runoff, industrial discharges, and urban waste. In some regions, up to 40% of lakes may be considered polluted. Ongoing monitoring and research are essential to address and mitigate this issue effectively.