These E numbers have been proven to cause cancer:
E 212, 213, 214, 215, 216, 217
Other E numbers are classified as "suspicious".
Using cheap soya sauce causes a condition called Chinese Restaurant Syndrome. I've had it and it is signified by a yukky headache.
Others cause intestinal disorders.
Check out the link to see which ones do what. Better yet, don't eat anything with these contaminants in them.