A study commissioned by Madagascar-focused British environmental charity The Andrew Lees Trust found high concentrations of uranium and lead in water downstream of Rio Tinto's 80%-owned QMM ilmenite mine in Madagascar, Reuters reported Dec. 20.

The water, which is used by local residents for drinking, contained 350 times higher concentrations of uranium and 9.8 times higher concentrations of lead downstream of the mine than upstream.

The minerals, if ingested, can interfere with mental and physical development of children as well as damage kidneys, according to the report.

Rio Tinto denied that the increased levels of lead and uranium in the water were caused by its mining operations.

"The minerals in question are recognized as being present at relatively elevated levels in the natural environment with or without QMM operations," a Rio Tinto spokesman told Reuters.

The government of Madagascar owns a 20% stake in the QMM mine.

In April, Rio Tinto accepted responsibility that the QMM mine threatened to pollute a body of water used by locals as its drinking water source, Mining Technology reported.

The Andrew Lees Trust accused the company's Mandena operation, part of the QMM property, in September 2018 of polluting nearby local water sources with radioactive substances.