The Ganges is one of the largest rivers in Asia. It rises in the Himalaya Mountains and flows over 2,500 km through India and Bangladesh into the Bay of Bengal. However, the Ganges, India's holy river, is also one of the most polluted in the world. The Ganges River basin has a size of over 1 million square km. It lies in one of the most populous regions on earth. About 500 million people, half of India's overall population, live in the Ganges river plains. There are many causes of Ganges river pollution. About 2 million Hindus bathe in the river every day. During religious ceremonies, up to a hundred million people clean their sins away in the Ganges River. They believe that bathing in the river will make them pure. In addition, thousands of bodies are cremated near the river, especially around the holy city, Varanasi. The ashes are often released into Ganges. The Ganges also provides water for farming land, which is increasing at a tremendous rate. Irrigation projects cause water levels to go down along the river. More and more dams are being erected along India's holy river, mainly to produce energy for Delhi and other large cities in the area. The river flows through 30 cities with a population of over 100,000 each. Every day, 3 billion litres of untreated water from these big cities pass into the Ganges River, along with remains of animals. Because of India's lax environmental regulations, industries along the river release chemicals and other poisonous material into the Ganges. In some places they are a thousand times over the allowed limit. Especially India's traditional leather industry needs great amounts of water. In addition, fertilizers from the fields find their way into the ground water, and ultimately flow into the river. Altogether, the amount of industrial pollution has doubled in the past 20 years. This widespread pollution of the Ganges River has also led to major health problems. Many diseases are common, including cholera, hepatitis and diarrhea. While India's population keeps growing, more and more people are leaving the countryside and moving to big cities along the Ganges. As a result, the river will not be able to cope with even more people. Life in the river is also at risk. Recent reports have shown that there is a high level of mercury in some fish. The construction of dams is destroying forests and vegetation, killing off many animal and plants. Indian authorities are fighting an upward battle towards cleaning up the Ganges River. International organizations have offered help. The World Bank has agreed togive India a loan of up to a billion dollars to clean up the Ganges River.