BUENOS AIRES (AP) ― The picturesque La Boca district draws hordes of tourists to stroll its narrow streets lined with colorful buildings and eat at outdoor restaurants. Now it has a new, unwanted claim to fame: The Riachuelo river flowing through the neighborhood has been named one of the planet’s 10 dirtiest places.

Thousands of people live along the river, and environmentalists say a court-ordered cleanup of decades of industrial pollution and sewage has made little progress in five years. Many residents still need to be relocated under the court ruling, and toxic substances are still emptying into the Riachuelo.

On a recent day, tourists ambled along the Caminito walkway full of souvenir shops and cafes amid the funk emanating from the river. Although the odor of the brown-gray river can be overpowering some days, the historic district, which is known as a tango hotspot and home of the popular soccer team Boca Juniors, remains one of Buenos Aires’ top tourist draws.

“I smell it from my home, just a few blocks away, and I often have to keep the windows closed,” said Edgardo Gomez.

“When are they going to finish this cleanup plan?”

Many are asking the same question. About 3.5 million people live in the southern districts of Buenos Aires and the 14 nearby municipalities as the river flows some 60 kilometers from Buenos Aires province to just south of the capital.

A report by the environmental activist groups Blacksmith Institute and Green Cross of Switzerland stirred up Argentines by ranking the river as the eighth most polluted place in the world.

The study says makers of chemical products are responsible for more than a third of the contamination, and says tests indicate 80 percent of water taken from wells near the river is not safe.

The study does say several cleanup programs are making some “progress” with support from the World Bank.

About 20,000 people live near the river basin, while 15,000 industries discharge effluent into the river, the report says.

Environment Secretary Juan Jose Mussi last week accused the media and the report of exaggerating the river’s condition. But he also concedes the pollution problem is “not solved.”

Can the Riachuelo be saved? Experts say yes, although much needs to be done.

“There’s a long-term, high-cost solution that could take decades,” said Raul Estrada Oyuela, a member of Argentina’s Environmental Sciences Academy.

“This requires political will and thorough measures,” Estrada Oyuela said. One of the measures would be a strict restriction on dumping pollutants and raw sewage.

Today, muddy bubbles can be seen across the river’s surface. “These are gases produced by heavy metals on the bottom,” said Alfredo Alberti, president of the La Boca Neighbors Association.