It seems that Mexico has a swine flu problem. Lots of people seem to think it is perfectly OK to eat pork, but there are reasons why Jewish people were traditionally healthy. They followed health codes, one of which is to not eat pigs. Pigs are bottom feeders in the food chain, so they eat lots of waste material. Kind of like crustaceans that eat raw sewage off the ocean floor.
Given all the problems with chicken, which seems to be a much cleaner animal, it is surprising there has not been a major outbreak of some pig disease in recent memory until now.
If somebody cares about the environment in the US, they also would not be eating pig. They are not raised in a sustainable way there.