A thousand health professionals have backed an appeal for hospital staff to be given improved personal protective equipment.

Writing to political leaders in the UK, the group says there is growing evidence that tiny coronavirus particles can spread through the air and are seeking for general ward staff to be given the type of high-quality masks usually only worn in intensive care.

Research during the course of last year highlighted how it is also possible for the virus to be carried in what are called aerosols, drifting and accumulating in the air. This counters the early belief that to catch the disease you had to either be close to an infected person and hit by droplets from their coughs or sneezes or touch a surface they had contaminated.

Public Health England has issued guidance on what PPE staff in different settings require, although it has not been updated since October 2020. Across the UK, the guidance for hospital staff is to wear surgical masks in most areas. More sophisticated masks - a type known as FFP3 that includes an air filter - are only required in intensive care or when certain procedures are carried out that are known to generate aerosols.

Most infections are thought to have occurred indoors in badly ventilated rooms, and many studies have shown that the 'airborne route' can be an important factor.

The letter argues that healthcare workers are three to four times more likely to become infected than the general population. But they also emphasise that staff in intensive care units, who have the best level of protection, have about half the risk of catching the virus than colleagues on general wards.