At present, wearing a mask is not a "golden bell"

Governments need to treat information about mandatory mask wearing with caution to ensure the policy is fully effective, the researchers said

After officials in Bangladesh announced a law requiring masks, the number of linked trips rose instead of falling

"…daily mobility was statistically significantly associated with daily new cases," the researchers noted

Dr Zia Ward, associate professor at the University of Leeds' School of Chemical and Process Engineering, who led the research, said there was growing evidence from laboratory and observational studies that properly wearing masks could reduce the spread of the virus that causes COVID-19

"In Bangladesh, there is evidence that people may have taken the statement that they were required to wear masks as a signal that they can return to their normal life>

But that's not the case

The study, involving scientists from the University of Leeds and Bangladesh University, revealed so-called 'risk compensation', where people adopt high-risk behaviours if they feel an intervention makes them safer - for example, cyclists wearing safety gear Will drive faster after the cap

A study published today (January 10, 2022) in the journal BMJ Global Health

Some 160 countries have made masks mandatory

Bangladesh began to shut down from mid-March 2020 as the number of COVID-19 cases began to increase rapidly

The Bangladesh study included an analysis of Google's community mobile data, collected from cell phones and other Android devices

Data provides general location information about people

The analysis found "statistically significant evidence" that in the days following mandatory mask wearing, activity at specific locations increased within seven days:

• 5.

  
  

It takes about 10 days from when someone is infected until their cases are reflected in official data

Co-author Dr Sheikh Mokhlesur Rahman, from the Bangladesh University of Engineering and Technology, added: "Research suggests that mandatory mask wearing may have a risk compensation effect that reduces the intended effect of wearing a mask

Reference: “Face mask mandates and risk compensation: an analysis of mobility data during the COVID-19 pandemic in Bangladesh” 10 January 2022, BMJ Global Health .