The checks, carried out by local station Real Radio North West using using specialist wipes, found that 92 per cent of the 100-plus facilities examined carried traces of the drug.
They tested changing units in public toilets in shopping centres, hospitals, police stations, courts and churches.
Shadow health secretary Andy Burnham said the findings were 'shocking':
"These are some some shocking results. Cocaine use has become much more widespread and the figures illustrate that. The damage that cocaine causes to young people's health and their life choices are enormous.
"I have seen people fall by the wayside that have misused drugs and you have to get the message across that this is something that is incredibly damaging to their lives.
"We're looking at hundreds of police disappearing from our communities. It terrifies me because it's not just the activities of those selling on our streets, it's all the inquisitive crime that goes with these very addictive substances and the affect that has on the community."
The UK was named the 'cocaine capital' of Europe last month, with 4.8 per cent of people estimated to have used it over the last year.
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