Millions of Americans commute to work every day, but the day can often be ruined before it begins if someone is a victim of hashtag #harassment coming into work.

It might be a woman groped on a train or an immigrant told to go back to where they come from while walking from the parking lot to the office. Researchers have long known what happens to a worker’s productivity when they’re harassed in the workplace, but what are the effects when they’re harassed on their way to work?

Beth Livingston, a professor of management and entrepreneurship in The University of Iowa Tippie College of Business, said it’s important for businesses to know. While commute harassment is rarely studied and its impact is mostly unquantified, it’s just as real and can affect a workers’ performance just as much as in-office harassment.

Livingston said harassment can cause emotional and psychological effects that reduce their productivity and cause other workplace problems. Employees who have been harassed can be slower to get into their job for the day because they’re dwelling on the incident and unable to focus on their work. They may spend time ruminating about the incident, or lead to aggression, incivility, and low morale, which also affects their colleagues. They may even act aggressively or unprofessionally to those who remind them of their harasser.

Livingston said businesses can take steps to mitigate the damage and help their employees who have been harassed become more productive. They can provide a quiet space for harassment victims to calm themselves and work through the incident before they start working, form a support group where victims can share their experiences and realize they’re not the only person this happens to, or provide extra flex time to cope.