A layer of foam that has been described as fetid and even “toxic” has been spreading throughout the town of Mosquera, just outside Colombia's capital city, Bogota. Large clouds of foam have been seen lifting off the river's surface into the air and being sent flying around the town, clinging to wherever it lands.
The foam is a combination of the discharge of chemical surfactants from industry and households in waterways surrounding the town. As the river flows beneath rivers or in canals, turbulence increases which can create foam with the right substances in the water. Although the pheromone is not new, it appears to have been exacerbated by the rainy season
The town's mayor, Gian Gerometta, tweeted to say the problem of waste and detergents in the River Bojaca was being aggravated by the rainy season and vegetal matter in the water. Although there were fears the foam may be toxic, Gerometta explained in a Twitter thread no threat ot public health had been found.
"Together with the Ministry of the Environment, the Ministry of Health, the Risk Management Directorate, the Municipal Personería, the Regional Autonomous Corporation (@CAR_Cundi) and the Fire Department, we have monitored and accompanied the Los Puentes sector," he said. "The team from the Ministry of Health found that there are no effects on the population that are related to this environmental problem."
However, inhabitants have started using inhalers to counteract the “fetid smell” that emanates from the foam.
Town officials also confirmed that removing some plants from the river bed might reduce river turbulence and so reduce the chance of foam forming.