Nishiyama said the increase was a concern, but also said the area is not a source of seafood and that the contamination posed no immediate threat to human health.

Advantages sof direct sampling are that areas hardest to clean and which are reasonably accessible can be evaluated, leading to establishing a level of contamination or residue per given surface area.

Changing and washing should follow a written procedure designed to minimise contamination of clean area clothing or carry-through of contaminants to the clean areas.