'Death' mucus has haunted Venezuela for 40 years

The mysterious black mucus killed 1,800 people in just the first five years after it appeared on a stretch of highway near Caracas.

In 1986 in Venezuela, a strange venom -like mucus oozed from a busy highway connecting Simón Bolívar International Airport to the capital Caracas. Just as quickly as it appeared, the mysterious mucus named La Mancha Negra (black spot) began to spread, turning the highway into a death trap for drivers, according to IFL Science .

Mucus of unknown origin becomes a threat to many drivers on the highway. (Photo: Pinterest)

The black slime first appeared on a 46m stretch of tarmac on the motorway and continued to expand until it covered 13km with a thickness of 2.5cm in some places. Black as tar, the mucus has the consistency of chewing gum. In the first 5 years after its appearance, La Mancha Negra claimed the lives of 1,800 people who tried to cross the path it "swallowed".

Although it briefly disappeared for no reason in the 90s, La Mancha Negra reappeared in 2001 and remains just as mysterious. To this day, this is still a mystery leading to many conspiracy theories.

One theory is that the slime was created by a batch of poor quality asphalt, which helps explain its tar-like appearance. Asphalt contains tar, a substance that becomes extremely sticky when heated. Like tar, one of the important characteristics of La Mancha Negra is that it reacts to the weather, expanding when it is hot and rainy, and contracting when temperature and humidity decrease.

Another theory is that the mucus resulted from a nearby natural crude oil field. Caracas city is located near the Orinoco belt, using pipelines to transport heavy oil to Caracas and many other Venezuelan cities. However, Ramanan Krishnamoorti, a professor of chemical and petroleum engineering at the University of Houston, said "usually, a leak from a near-surface mine needs to be located at the fault point and is less likely to spread across the road." 13km long like that. In addition, heavy oil usually settles and does not leak onto the ground."

Reinaldo Gonzalez, a lecturer in the petroleum engineering department at the University of Houston who was in Venezuela during the 1986 incident, said the simplest possible explanation is that the stages of applying treated asphalt were separated, One of them "floats" to the surface, creating a slightly sticky black streak on the road.

According to another theory, raw sewage from neighboring slums is behind, causing the asphalt to chemically decompose as it flows downhill below the road. Others said it was burning rubber from tires or oil leaking from the car engine.

One leading theory speculates that defective asphalt is the result of poor government budget management, skimming money through the use of substandard materials in road repair and maintenance. There is even speculation that both the government and private companies generate large profits by repeatedly carrying out road repairs and lengthy cleanup efforts.

In 2001, when the mucus appeared for the second time, Caracas mayor Freddy Bernal claimed to have hired people to throw used oil bags onto the highway at night to tarnish his reputation. Although the sample contained 60% brake fluid and 40% used oil, indicating that the substance was intentionally created, Bernal's claim is unsubstantiated and cannot explain the first leak of mucus. .

However, the Venezuelan government has spent millions of dollars to understand the composition of mucus. But despite hiring experts from the US, Canada and Europe, chemical tests could not verify what was inside the mucus. Authorities also tried many times to find ways to clean it with water, air and scrape off the sticky compound from the road surface, but all efforts failed. The mucus seemed to be spreading again. They even tried to dry it out by pouring crushed limestone on the road. However, this only creates additional problems as the dust from the limestone affects air quality and visibility in the area.

Traffic congestion has become common on busy highways. Red warning signs are posted to remind drivers to slow down. Local residents and taxi drivers will avoid driving on the highway. The area is closed four nights a week so workers can temporarily repair the road surface.

Although the exact details of the mucus remain controversial, it caused real chaos in Venezuela for years before suddenly disappearing without explanation in the 1990s. Researchers still don't know what stopped it. La Mancha Negra. They speculate that massive landslides in 1999 that spurred new road construction may be part of the reason. However, they could not stop La Mancha Negra because it reappeared in 2001. A report on the current status of La Mancha Negra said it stopped in the early 2000s.