evidence: People opposed to mask mandates have staged protests, and one local health official in Orange County, Calif., quit her job after receiving a death threat for a mask order. Not long after, California Gov. Gavin Newsom ordered Californians to wear face coverings in public. Meanwhile in Texas, Gov. Greg Abbott recently allowed some counties to impose mask mandates on businesses, despite an earlier order forbidding penalties on individuals for not wearing masks. [...] Other recent studies offer indirect evidence for universal mask use, even if worn by people who are feeling healthy. One study, published in late May in BMJ Global Health, looked at people in households in Beijing where one person was confirmed to have COVID-19. At the time, explains study co-author Raina MacIntyre, research was already showing that the majority of transmission of the virus was happening inside households, and China already had a culture of mask wearing. The study found that in households where everyone was wearing a face mask indoors as a precaution before they knew anyone who lived there was sick, the risk of transmission was cut by 79%.