Pollution of the Pasig River

The Pasig River in the Philippines suffers from a high level of water pollution and efforts are being made to rehabilitate it.

After World War II, massive population growth, infrastructure construction, and the dispersal of economic activities to Manila's suburbs left the river neglected. The banks of the river attracted informal settlers and the remaining factories dumped their wastes into the river, making it effectively a huge sewer system. Industrialization had already polluted the river.^[1]

In the 1930s, observers noticed the increasing pollution of the river, as fish migration from Laguna de Bay diminished. People ceased using the river's water for laundering in the 1960s, and ferry transport declined. By the 1970s, the river started to emanate offensive smells as a result of waste from swine and poultry establishments in the area where protected Marikina watershed is located (Pinugay, Baras, Rizal) and in the 1980s, fishing in the river was prohibited. By 1990, the Pasig River was considered biologically dead.^[1][2]

In 2017, a study on river plastic emissions into the world's oceans cited the Pasig River as the world's eighth most polluting river in terms of unwanted micro and surface concentrations of plastic waste entering the marine environment.^[3]

In 2021, a research by the American Association for the Advancement of Science on the world's rivers ranked the Pasig River as the largest contributor of plastic waste to the world's oceans, additionally claiming that 28% of the rivers causing plastic pollution globally are in the Philippines.^[4][5]