Men visse pressionsgrupper har sagt at afspore forskningen i retning af pesticider, mens WHO i 1984 slog fast, at optagelse af forgiftet, forfalsket spiseolie var den eneste sandsynlige årsag til sygdom men.
Certain pressure groups, however, have tried to divert the research towards pesticides, whereas in 1984 the WHO established that absorption of adulterated contaminated