Gross!
From the guy who drinks tuna from the can to the person who snores at their desk, dealing with gross colleagues can be a real challenge. So what can you do to fix things? One option is to directly converse with them and politely ask them to clean up their act (or their toenail clippings).
Another approach is to start a “clean desk” initiative in the office and make it a group effort to keep things tidy and hygienic. Or you could always start wearing a gas mask to work. Of course, these tactics might not solve the problem completely, but they might make your work environment more bearable.