Manaus is the largest city in the Brazilian state of Amazonas, home to more than 2 million people, located near the point where the Rio Negro – a tributary of the Amazon River which accounts for up to 14% of the discharge in the Amazon basin – joins the Solimões, the name given to the upper Amazon River.
Every day, close to 30 tonnes of debris is pulled from the waterways running through the city, informs Phys.org. The floating debris, including plastics and other wastes like home appliances mixed with leaves and tree branches, covers the water surface to the point that the water cannot be seen in some areas.
Although the amount of trash in the water usually increases at this time of year, the local authorities think it is getting even worse. A total of 4,500 tonnes of trash have been collected between January and May.
Locals complain that “the people who live on the water's edge throw garbage straight into the streams... few people put it in the trash". The city estimates it could save around $190,000 every month in clean-up costs if there was more awareness of the problem, the undersecretary of sanitation Jose Reboucas told AFP.
Manaus is in the middle of the Amazon Rainforest, with unparalleled biodiversity. The urban area covers all or part of four river basins, all of them tributaries of the Rio Negro. Floating pollution in its waterways will eventually end up in the Amazon River.
A 2019 study pointed to plastic pollution as an emerging threat in the Amazon region, already subject to the impact of deforestation and other adverse environmental impacts derived from economic activities. It is a complex challenge with different aspects, including lack of adequate waste management and lack of awareness, compounded by torrential rain and frequent floods that wash plastic waste into waterways. Much of the trash ends up in rivers, making the Amazon the world’s second most polluted river in terms of plastic, only behind the Yangtze River in China.
Plastic waste can end up trapped in flooded forests an degrade into microplastics that pose additional threats to the Amazon ecosystem. Ingested by fish, the effects of human consumption of microplastic particles are unknown but pose a concern for public health. The consequences are far reaching, as plastics and microplastics will eventually reach the Atlantic Ocean, contributing to the growing global pollution problem.