The word 'untreated' is correct and usable in written English.
You can use it when you want to describe something that has not been processed, handled, or dealt with. For example, "The untreated water was murky and had a foul smell."
In adults, it can cause chronic illness through damage to the liver, intestines, lungs, and bladder that, if left untreated, may result in death.
Nick Martlew, senior conflict and humanitarian advocacy adviser at Save the Children, said: "We're already seeing an impact on children's health, with increasing numbers suffering from conditions such as diarrhoea, hepatitis A and upper respiratory tract infections – all of which can be deadly if left untreated.
Most sewage from the camps was collected by trucks and dumped untreated in lagoons at a waste site only metres from the sea, or anywhere out of sight.
The fever may be the result of an infection which, if left untreated, could be life-threatening.
Gehry going back to his youth of rough-and-ready steel and untreated plywood.
Gonorrhoea, or "the clap", can be similarly silent – with around half of women not experiencing any symptoms, and can also lead to infertility if left untreated.
On Saturday the Met Office issued a severe weather alert – predicting temperatures would fall sharply, with the risk of widespread ice forming on untreated surfaces.
The sheer profusion and extent of some of these deformations leads the viewer to see the past with different eyes, and imagine the horror show the pays-bas of Britain's cities must have provided, when there were so many of the untreated wandering its pullulating byways.
At the time, London was in the grip of an epidemic of cholera, a disease that triggers vomiting and diarrhoea; it can still lead to death if untreated.
The plan is to avert 55m tonnes of "untreated sewage" (this is actually storm sewage, 95% of which is rain water) from overflowing into the River Thames.
Such mice lived for 100 days longer when treated with the new molecules than they did when untreated.
