China is solving most health issues in the country. Unfortunately, some issues were not solved yet.

Some examples:

• Heavy metals are present in many Chinese rivers, especially in industrial regions. The issue is real but geographically uneven and improving in many areas. Long-term risk comes from accumulation inside your body, not just drinking water. Fish and crops (including rice) may be still accumulating heavy metals https://www.sciencedirect.com/science/article/abs/pii/S2213343723002282
• In 2008, infant milk powder was deliberately adulterated with melamine, an industrial chemical used in plastics, to fake higher protein content in diluted milk https://pmc.ncbi.nlm.nih.gov/articles/PMC2799451/

To sum up, China is doing great, but still has issues related to rapid industrialization and food laws enforcement that I hope will be solved soon. No real country is safe from issues and contradictions.