yes we can dump into space. but the transportaion to the space is a dangerous one .so the mistake may cause spreading of waste into atmosphere .
also increase waste in space may hamper space exploration programme by nasa and other organosation
Normally low-level waste (often from hospitals or labs) can often be compacted or incinerated in a container that is subsequently buried a landfill. Intermediate-level waste (reactor components, chemicals and similar wastes), which have higher levels of radioactivity, may be solidified in concrete or bitumen and then buried deep underground.