There are many things that worry Fina Kao about working in a busy donut shop in an age of fear about a spreading virus. The elderly customer who shuffles across the brown linoleum floor of the shop, orders a glazed donut, and then coughs. The parents sitting at a table sharing a breakfast sandwich as their small child touches the tables and the floor and the drinks fridge with her dirty fingers. The regulars who come in and who Kao knows travel annually to China—one of whom proceeds to sit at the window and cut his fingernails. The fact that California now has 53 confirmed cases of coronavirus, more than any other state.

But Kao and her fellow workers at All Stars Donuts in the Richmond district of San Francisco don’t have much choice but to show up to work, their only shield from potential coronavirus carriers a 24-ounce bottle of aloe hand sanitizer they’ve put near the register. Kao works five days a week from 5 a.m. to 1 p.m. “If we don’t work,” says Kao, 31, “we don’t get paid.”

While employees of companies like Twitter are being encouraged to work from home to protect themselves from the virus, known as COVID-19, people like Kao, whose jobs depend on in-person interaction, feel more exposed than ever. In this way, the spread of the coronavirus exposes a widening chasm in the U.S. economy between college-educated workers, whose jobs can be done from anywhere on a computer, and less-educated workers who increasingly find themselves in jobs that require human contact. Since 1980, as automation has spread in the workplace and companies have sent more jobs overseas, economists say the labor market has polarized, with employment growing in high-wage jobs that require a lot of education and in low-wage jobs that don’t. Many of the low-wage jobs available are the type of non-routine service work that can’t be automated or outsourced —things like cleaning an office, changing a diaper, delivering a package, cooking an omelet.

Around 86 percent of U.S. workers are employed in service industry jobs, up from 68 percent in 1970, according to the Bureau of Labor Statistics. People in these non-routine, in-person jobs are already facing low pay, few benefits, and uncertain hours. Now, these workers are facing another challenge: “Because workers in these positions often have substantial face-to-face customer contact, they face elevated coronavirus exposure risk if the virus spreads,” says David Autor, an MIT labor economist.

Read the rest of Alana Semuel’s article here at TIME