Joe Palca is a science correspondent for NPR. Since joining NPR in 1992, Palca has covered a range of science topics — everything from biomedical research to astronomy. He is currently focused on the eponymous series, "Joe's Big Idea." Stories in the series explore the minds and motivations of scientists and inventors. Palca is also the founder of NPR Scicommers – A science communication collective.
It's the latest corner of the human body where tiny bits of plastic have turned up -- the testicles. Exposure to environmental toxins like microplastics are believed to be contributing to the global decline in sperm count in humans.
Violent storms and tornadoes swept across Iowa on Tuesday, leaving multiple people dead and dozens injured. The city of Greenfield in southwestern Iowa took a direct hit from a powerful twister.