I usually work in fairly professional buildings in Central London, but as an unusual job, I'm currently working in a building in zone 5. There are several recruitment agencies who recruit for low-paid work, and a lot of visitors to the building seem to be from disadvantaged backgrounds, or don't speak English very well, or don't seem to communicate very well. All very important work of course, but what I've noticed is that so many of them chew gum. The noisy, open-mouthed type of chewing. It's not just the visitors, but also a lot of the people who work here.
Is there some reason for this? The difference is really pronounced. I can't stand chewing but I'm really trying to be professional and understanding to everyone.