Possible Ecotoxicity in the Pacific Northwest?

After testing shipments of geoducks and oysters and seeing positive results for Arsenic and PSP (a biotoxin produced by algae) China banned all shellfish imports originating from the West Coast. More specifically, geoducks harvested from Poverty Bay in Redondo, Washington were targeted as having high levels of Arsenic. It is believed that China uses a much stricter measurement system than America, as Poverty Bay had been recently tested to determine the safety of the shellfish harvested there. American studies found the shellfish to be safe for human consumption, but really, how acceptable is any level of arsenic in your food? It's understandable that China would halt imports of shellfish if there was even the slightest possibility of it harming someone. Because of the results of the American study, it has led some to think that the ban was more rooted in political issues with the health concern being a convenient excuse to implement the ban.