Fifty years of research suggests police behavior makes the biggest difference in how safe protests are for everyone. Plus, how tear gas ups COVID-19 risk.
Plus, understanding false negative results in COVID-19 tests and the sounds of elusive narwhals, captured on tape.
The Trump administration is paving the way for polluters.
A Harvard research team finds that an increase of one part per billion of air pollution is linked with an 8% increase in COVID-19 mortality.
Plus, a breakdown of this week’s COVID-19 news, including what we do and don’t know about the virus in semen and coronavirus mutations.