This is a question of people's heart and society, and it is also a question of law. . .
Back to the topic, at the chemical level, the current food safety is mainly due to the lack of some comprehensive national standards to restrict the use and input of chemicals in China. Because the country is too big, supervision is more important.
What I said above about health is that food problems have a positive impact on health. Eating something that shouldn't appear, absorbing it but not metabolizing it, will definitely do harm to the body.
Health is only the consequence, chemistry is only the method, and the root of food safety is legal constraints and social speculation.