The Police Federation described the "appalling" rise in offences nationally as a stain on society and said emergency workers should be able to carry out their duties safely.
Home Office figures show Gwent Police recorded 446 assaults on emergency workers in the year to March.
Most of the alleged victims were police constables – there were 268 assaults without injury on PCs last year and 112 with injury, while there were 66 on other emergency workers.
The total number recorded last year was up from 211 in 2020-21, when assaults on emergency workers who are not police constables were recorded for the first time.
Across the two nations, 44,600 emergency worker assaults were recorded in 2021-22 – a rise of 10% on the 40,400 the year before.
Since the Assaults on Emergency Workers Bill came into law in 2018, the maximum prison sentence for common assault on an emergency worker has been 12 months.
The offence applies to attacks on 'blue light' workers such as the police, paramedics and fire fighters, along with many others, including prison officers, NHS workers, and St John’s Ambulance volunteers.
The Police Federation said the rise in assaults on emergency workers is appalling and must not be tolerated or seen as just part of the job.
Steve Hartshorn, national chairman of the organisation, added: “Crime levels rose once Covid restrictions were lifted and a split-second act of violence, whether an injury is sustained or not, often leaves devastating and long-term effects on police officers.
"The physical and mental scars of these assaults can last a lifetime and are unacceptable.
“Assaults on emergency workers are a stain on society and many of these assaults which are recorded without an injury would have been vile spitting and coughing attacks."
He said it is vital judges and magistrates make full use of the new law to ensure the sentence handed down reflects the seriousness and gravity of the crime.
Separate figures show that the proportion of offenders charged has fallen nationwide, from 68% to just 62% in 2021-22.
However, in Gwent, 368 emergency worker assault investigations concluded last year, with 64% resulting in a charge or summons – up from 62% in 2020-21.
PTSD 999, a support organisation for all emergency services, said stronger sentencing for offenders would protect both the public and those facing assaults.
Gary Hayes, co-founder of the group, said: "Assaults on emergency service workers can be traumatising but not necessarily at the time of the event, the effects on the individual may present itself days, weeks, months or years later.
"There is no time scale as to how and when someone may start to struggle with an assault."
A Government spokesperson said: “Assaults on members of our emergency services are unacceptable, which is why this government has doubled the maximum penalty for assaulting an emergency worker."