Many parents who recently dropped off their college students at dorms and apartments across the country worry about drugs — and rightly so. The use of marijuana by college students is increasing, and its use is increasing at a faster pace in those states where recreational marijuana use is legal.

David Kerr, Ph.D., a professor in the School of Psychological Science at Oregon State University, reported on the findings from seven universities — one large public Oregon university, where recreational marijuana use is legal, and six universities in states where recreational marijuana use was illegal. The study surveyed 10,924 undergraduate students in the years 2012 to 2016.

Of note, was the legalization of recreational marijuana in the state of Oregon. The study found that the students in Oregon had increased the use of marijuana at a greater rate compared to the other universities under study.

Soon, two states with high enrollment of students in public and private universities are going to be faced with a similar problem, thanks to recent legalization efforts last November California and Massachusetts.

California has 314 colleges: 154 public and 158 private. Massachusetts has 114 colleges; 30 public and 84 private. The city of Boston alone has 250,000 college students. Boston University has 32,000 students, and the University of California Los Angeles (UCLA) has 28,236 students.

Despite marijuana being legal in both states, it is not legal to have or use on any campus in the University of California system. This is going to create problems throughout the university community and residences. The marijuana smoking ban is loosely associated with the policies against on-campus use of tobacco or alcohol and, if violated, could result in dismissal from school.

There may be changes in the culture in some campuses. While not wholly serious, the UCLA student newspaper made comments about the formation of a weed club and specialized gardening clubs. But Babson College in Massachusetts has a group that organizes educational content around cannabis/marijuana entrepreneurship. They also have a club of sorts.

Bigger universities like Boston University are prepared for students this fall.

"The enforcement policy will continue for those under 21 and for smoking in public," said Scott Pare, the acting chief of the Boston University Police Department. "The use, possession, distribution, or cultivation of marijuana for recreational or medical purposes is not allowed in any Boston University residence hall or on any other Boston University premises. Nor is it allowed at any university-sponsored event or activity off campus or at any student organization event or activity."

He went on discuss violators facing "civil citation, state or federal prosecution, and university discipline."

Kerr also expects this increase of marijuana use to expand to states where recreational use remains illegal.

"It's likely that the rise in marijuana use across the country is tied in part to liberalization of attitudes about the drug as more states legalize it, for recreational or medical purposes or both," Kerr said. "So legalization both reflects changing attitudes and may influence them even outside of states where the drug is legal."

College towns, and in particular those in states where recreational marijuana is legal, must gear up to handle the social, physical and legal consequences of those students who are temporary residents.