This is an incredibly misleading way to talk about this. First, there are ~200 countries, not 106. Second, Puerto Rico IS the USA. Third, "84th most polluted"

This is an incredibly misleading way to talk about this. First, there are ~200 countries, not 106. Second, Puerto Rico IS the USA. Third, "84th most polluted" out of a list of 106, is just a weird way to talk. It's like saying the valedictorian of a class of 100 is the 100th most underachieving student.