Prospect is supporting the campaign, called Time to Breathe, which calls on employers, policymakers and regulators to start taking seriously the health risks of ambient air pollution.

Research published in August 2018 by the government’s Committee on the Medical Effects of Air Pollutants estimated that 36,000 people die prematurely each year because of air pollution.

While there is growing recognition that air pollution is a public health emergency, outdoor workers have been largely overlooked.

The main pollutants of concern are particulates, nitrogen dioxide and ground level ozone, which are largely caused by, or a consequence of, the combustion of fossil fuels

Time to Breathe is also offering a free app called Canairy, built in partnership with King’s College London’s Environmental Research Group.

It uses the world-leading data from London’s Air Quality Network (LAQN) to model workers’ exposure to air pollution. It only works in the capital.

Canairy provides tips to workers about reducing their exposure to air pollution. The data it generates will help employers, in partnership with employees, make more informed decisions about scheduling work to avoid unhealthy levels of exposure.

Exposure to the various pollutants is pegged against limit values created by the World Health Organisation (WHO), which has undertaken a significant amount of research on the health impacts of air pollution.

The British Safety Council has produced general guidance for employers, which contains advice on how to limit workers’ exposure to pollutants. A guide for health and safety reps is in the pipeline.