🔍 Quick Facts
Topic: rivers ranked by severity of human-caused pollution
Core idea: there is no single official global ranking of the world’s most polluted rivers, because pollution can mean very different things: untreated sewage, industrial chemicals, heavy metals, pathogens, plastic waste, pharmaceutical residues, or combinations of them. A major global study in PNAS found pharmaceutical contamination in almost all sampled rivers, with some concentrations potentially toxic to aquatic life, which shows how hard it is to reduce river pollution to one metric.
When people talk about the “most polluted rivers in the world,” they usually mean rivers whose pollution is both extreme and socially consequential—rivers where contamination is obvious, chronic, and dangerous to ecosystems and nearby populations. On that basis, some names appear again and again across credible reporting and institutional sources: Citarum, Buriganga, Yamuna, the Ganges, the Marilao-Meycauayan-Obando river system, and the Pasig.
For Rivers.wiki, the key point is that “most polluted” is not a purely technical title. It is an editorial judgment built from severity, scale, pollutant type, and human impact. The ranking below is therefore a reasoned comparative ranking, not a formal international league table.
Ranking table
Table 1: Most polluted rivers in the world
| Rank | River / river system | Why it ranks so highly |
|---|---|---|
| 1 | Citarum River (Indonesia) | severe industrial and domestic pollution; widely described as among the world’s most polluted rivers |
| 2 | Marilao-Meycauayan-Obando river system (Philippines) | one of the worst polluted water bodies in the world; heavy metals, chromium, lead, sewage |
| 3 | Buriganga River (Bangladesh) | water described as pitch black; industrial and human waste; biologically degraded |
| 4 | Yamuna River (India) | extreme sewage loading, industrial pollution, toxic foam, severe water-quality failure in Delhi stretch |
| 5 | Ganges River (India) | highly polluted over much of its course by sewage, industrial waste, runoff, pathogens, and toxic substances |
| 6 | Pasig River (Philippines) | heavily polluted urban river, major plastic-waste source, long regarded as one of the world’s most polluted rivers |
This ranking weighs severity, persistence, and human/ecological harm, not just one pollutant type.
1. Citarum River
The Citarum River in Indonesia is the strongest candidate for number one in a broad public-interest ranking. A 2023 UNDP Indonesia article says that in 2018 the Citarum was considered one of the 10 most polluted rivers in the world, and it describes the river as being choked by toxic waste from factories along its basin. The same article notes that the basin hosts more than 2,000 industries, helping explain why contamination became so severe.
What makes the Citarum especially alarming is the combination of industrial waste, household pollution, and direct human dependence. UNDP notes that the river provides water to major urban areas including Bandung, Jakarta, and Tangerang, meaning pollution is not confined to an isolated industrial corridor but affects millions of people.
2. Marilao-Meycauayan-Obando river system
The Marilao-Meycauayan-Obando (MMO) river system in the Philippines is one of the strongest contenders for the top tier. Pure Earth describes it as “one of the worst polluted water bodies in the world” and says it feeds directly into Manila Bay. The organization also describes the basin as a catchment of untreated household, commercial, and industrial waste.
Pure Earth’s project pages give unusually concrete details about the contaminants: the system contains carcinogenic hexavalent chromium, lead, and human sewage, and the local population relies on it as a source of domestic and agricultural water. That combination of toxic industrial pollutants and human exposure is exactly why the MMO system belongs near the top of any world pollution ranking.
3. Buriganga River
The Buriganga River in Bangladesh is one of the most visibly degraded rivers in the world. A 2023 Reuters special report says the Buriganga is so polluted that its water appears pitch black outside the monsoon season and emits a foul stench through the year. Reuters also reports that untreated sewage, dyeing by-products, and chemical waste from mills and factories flow into it daily.
Reuters further reports that people bathing in the river suffer skin and eye irritation, and cites local environmental advocates describing the river as “biologically dead” in the dry season, with no fish or aquatic life. That makes the Buriganga one of the clearest examples of a river whose pollution is not only severe but socially and biologically obvious.
4. Yamuna River
The Yamuna River, especially its Delhi stretch, ranks among the world’s worst polluted major rivers. Britannica says the Yamuna has become one of the most-polluted in India because so much of its course passes through densely populated areas where vast quantities of sewage have been discharged directly into it.
The most current official evidence in the retrieved sources comes from India’s Press Information Bureau, citing CPCB and Delhi Jal Board data from 2025. It says Delhi generates 3,596 million litres per day of sewage, that 641 MLD remains untreated and enters the river or drainage network, and that 14 of 37 operational sewage treatment plants were non-compliant with norms at the time reported. Those figures show why the Yamuna’s pollution remains chronic despite long-running cleanup programs.
5. Ganges River
The Ganges is one of the world’s most spiritually important rivers, but it is also one of the world’s most polluted major rivers. Britannica states that the river’s water over much of its course is highly polluted, with untreated sewage from cities and towns, industrial waste from manufacturing facilities, agricultural runoff, animal carcasses, and cremation-related remains all contributing.
Britannica also states that high levels of disease-causing bacteria and toxic substances including chromium, cadmium, and arsenic have been found in the river. That combination of pathogen loading and toxic contamination makes the Ganges one of the clearest cases where a river is both culturally central and environmentally endangered.
6. Pasig River
The Pasig River in Manila belongs on this list because of its long-standing reputation for severe urban pollution and plastic waste. A 2021 Reuters report describes it as one of the world’s most polluted rivers and says the river was left all but dead by urbanization and poor sewage planning. Reuters also reports that the Pasig contributes significantly to ocean plastic emissions.
The Pasig’s danger lies in the combination of solid waste, sewage, stagnant polluted water, and urban exposure. Reuters’ reporting on volunteers collecting vast quantities of river trash shows that this is not an abstract water-quality issue; it is a visible daily crisis in the middle of a large capital city.
How to read this ranking
This ranking should be understood as a comparative pollution-severity list, not a precise scientific index. Some rivers rank high because of heavy metals and industrial toxins; others because of pathogens and sewage; others because of plastic and urban waste. A river that is “worse” on one measure may be less extreme on another.
That is why a mixed-method editorial ranking is more honest than pretending one single pollution number settles the question. The rivers listed here all have strong evidence of extreme contamination, but their pollutant profiles differ substantially.
🌊 Why It Matters
The world’s most polluted rivers matter because river pollution is not just an environmental problem. It is also a public-health problem, a food-security problem, and a livelihoods problem. In the cases above, people still rely on these rivers for water, transport, fishing, irrigation, or nearby employment even when the rivers are visibly contaminated.
For Rivers.wiki, this topic is especially important because it shows how badly a river can be damaged when wastewater, industrial effluents, and plastic waste overwhelm its natural capacity. A polluted river is not just a dirty river; it is often a river whose ecological functions, social value, and human safety have been deeply compromised.
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