Itsu bean and hijiki lunch roll

This year I have been eating a lot more Japanese food - mainly because I really like it but also because its good quality food. Itsu who have a takeaway stall outside my office provide me with excellent miso soup and what they call a lunch roll nearly every working day. The lunch roll is a tube of rice with different ingredients rolled up inside. Mostly I have ginger chicken - very spicy! Since last week though I have purchased the Bean and Hijiki lunch roll and very satisfying it is. I was interested to know what hijiki is and looked it up on the web today and hijiki is a black seaweed finely sliced but I also to my horror read that hijiki contains inorganic arsenic that is known to add to the risk of people developing cancer. I read this on the Food Standards Agency website - a UK government agency. I have also pinged off a question to Itsu about the use of hijiki in their lunch rolls using the Itsu question form. Hopefully I will get a concise answer back as to the risks of eating Itsu's hijiki. Update! I got a quick email response from Glenn at Itsu : Yes it does reassure me! I can continue to choose the Bean and Hijiki lunch roll for my lunch without any worries!