Close to 40% of the secondhand clothes that are imported into the two East African countries of Tanzania and Kenya are of such deplorable quality that they can't be sold anymore—those are essentially textile waste dumped there in the guise of pre-loved clothing.
A fact-finding study of the use of secondhand clothing by Greenpeace found that huge amounts of textile waste that Tanzania and Kenya are flooded with daily have severe consequences for people and the environment. The findings were presented in a report titled Poisoned Gifts: From donations to the dumpsite: textiles waste disguised as secondhand clothes exported to East Africa.
The numbers are staggering. The report mentioned: "In Kenya, 185,000 tonnes of second-hand clothes were imported in 2019, and according to Africa Collect Textiles and other local sources local sources, 30–40% of mitumba is of such bad quality that it cannot be sold anymore. This means that 55,500 to 74,000 tonnes of it was actually textile waste. This amounts to about 150–200 tonnes of textile waste a day."
These countries do not have the requisite infrastructure (quite unlike the exporting countries), the fallout is this: textile waste is dumped everywhere, some of it is burnt leading to air quality issues, and a lot of the apparel trash gets dumped in rivers and drains, clogging them right away.
That's not all. As the report points out, "The decomposing clothes release methane, a harmful greenhouse gas that contributes to climate change; synthetic fabrics like polyester and lycra can take hundreds of years to biodegrade. In addition, many clothes contain hazardous chemicals, used during the production process."