As of January 8, 2014, over one thousand people have reportedly been made ill by pesticide known as malathion - and while an insecticide, its toxicity to humans is relatively low.
The matter has been referred to Gunma-ken (Gunma Prefecture) police where the contamination and food packing appears to have taken place because prefecture health officials could find no evidence of contamination during the actual production - meaning this appears to be poisoning case perhaps by a disgruntled employee.
As such, police are talking to about 300 employees of the packaged food plant.
Back on December 29, 2013, the Tokyo-based Maruha Nichiro said it was recalling about 6.4 million bags of frozen foods, including croquettes, frozen pizza (see image above) and chicken nuggets.
Now, lest we all start pointing fingers at Maruha Nichiro, note that a company spokesman has stated that it tests packed foods several times a day for spoilage in accordance to current Japanese food laws, but it does not test for pesticides because there was no reason to believe pesticides would ever be present.
In my opinion, Japanese food companies should perform internal (at the company) testing, as well as utilize the services of a third-party laboratory. The third-party should test for something - and I don't know what or how - but I really have no idea how you test for all known toxins or illnesses... it simply can't be done for every single batch of food products manufactured - not without the cost of food being driven up markedly.
Your damned if you do and damned if you don't.
In this case, with such a concentrated amount of pesticide present, it is difficult to not assume it was added during the production of the products by a disturbed individual. At the same time, by using a low-level toxic insecticide that should not kill anyone, it does show some level of chemical or medical knowledge.
Or it shows that they had assumed it would kill someone, and their plan failed miserably.
Whatever the reason, I'm glad no one seems to be in danger of dying.