Zinc (Zn) is enriched in carbonate area related to geological genesis. To ensure safety of rice, soil threshold values of Zn in soil–rice systems were assessed based on analysis of soil–rice Zn concentration in relation to human health risk. Models for the prediction of Zn concentration of early-season and late-season rice grain were accurately established on the basis of significant partial correlations between log₁₀ (BAFs) and log₁₀ (soil properties). The rice threshold value ranged from 10.67 to 37.90 mg/kg, which might not suitable for male and urban residents. The soil safety threshold of early-season rice and late-season rice in carbonate area ranged from 148–200 mg/kg, 119–200 mg/kg with pH below 6.5, 148–250 mg/kg, 119–250 mg/kg with pH ranging from 6.5 to 7.5; 148–300 mg/kg, 119–300 mg/kg with pH above 7.5, respectively.

锌（Zn）富含与地质成因有关的碳酸盐区域。为了确保稻米的安全性，在对土壤-水稻系统中锌的浓度阈值进行分析的基础上，对土壤-锌系统中人类健康风险的阈值进行了评估。根据log ₁₀（BAFs）和log ₁₀之间的显着部分相关性，准确建立了预测早季和后期稻米锌浓度的模型（土壤性质）。大米的阈值范围为10.67至37.90 mg / kg，可能不适合男性和城市居民。碳酸盐地区早稻和晚稻的土壤安全阈值范围为148–200 mg / kg，119–200 mg / kg，pH值低于6.5、148–250 mg / kg，119–250 mg / kg pH值在6.5至7.5之间；pH值分别大于7.5时为148-300 mg / kg，119-300 mg / kg。