The Irish Nurses and Midwives Organisation says the Trolley Watch figures are an early indicator of what the Winter season will hold.
August has been already been identified as one of the worst since Trolley Watch began and the union says the ongoing increase highlights the need for safe staffing legislation.
The union says all hospitals should have sufficient staff to diagnose, treat and discharge patients safely.
Cork University Hospital was again the second most overcrowded hospital in the country with 984 patients treated on trolleys at the facility last month.
Speaking to RedFM News Colm Porter of the INMO in Cork says the recruitment and retention crisis facing nursing will have a direct impact on patient care:
"Surveys that the IMO have undertaken over the past year shows that the main reason why nurses and midwives are leaving or would intend to leave is down to their working conditions. So the working conditions for our members have become so bad that they're actually considering leaving the profession. If this happens it will not only worsen the crisis of people without bed but it's going to be worse as there won't be nurses there to treat those patients on the trolleys"
