Short answers, pulled from the story.
The River Thames in London was declared biologically dead in 1952. This event marked a stretch of water so toxic that no fish could survive its depths while it remained the primary source of drinking water for millions of people downstream.
Water pollution results from human activities that introduce contaminants such as sewage discharges, industrial activities, agricultural runoff, and urban stormwater. These sources degrade aquatic ecosystems and spread water-borne diseases globally.
Approximately 4.5 billion people lacked safely managed sanitation as of 2017. This statistic directly correlates with the degradation of water quality worldwide and the spread of water-borne diseases.
Eutrophication is the process by which water bodies become overly enriched with nutrients like nitrogen and phosphorus from agricultural runoff and sewage. This leads to rapid algae growth that consumes dissolved oxygen, creating hypoxic conditions that suffocate fish and other aquatic life.
Approximately 35% of all ocean microplastics come from textiles and clothing due to the erosion of polyester, acrylic, or nylon-based clothing during the washing process. These microplastics persist in the environment for centuries and accumulate in the food chain.
The Clean Water Act was enacted in the United States in 1972. This legislation established a framework for regulating point source water pollution and requires infrastructure such as wastewater treatment plants to remove 90 percent or more of the pollutant load in sewage.