Objective To analyze the levels and potential health risks of dietary cadmium exposure among residents of Chongqing city from 2012 to 2022, and to provide a basis for regional decision-making on food safety.

Methods The detection data from 2012 to 2022 on cadmium concentrations of 9 219 samples from 11 food categories, including rice and rice products, wheat and wheat products, other grains and grain products, leafy vegetables, root and tuber vegetables, legumes, other fresh vegetables, poultry, livestock, fruits, and eggs and egg products, were collected from the Chongqing Food Safety Risk Monitoring System. The cadmium content in food samples was detected by graphite furnace atomic absorption spectroscopy according to the national standard (GB 5009.15–2014) and inductively coupled plasma mass spectrometry according to (GB 5009.268–2016). The limit of detection (LOD) for different food types ranged from 0.000 1 to 0.01 mg/kg, and the left-censored results were replaced by the middle bound (MB) and upper bound (UB) detections. Dietary survey data from 3 354 residents in 6 districts/counties of Chongqing city were also extracted from the three waves of the China Health and Nutrition Survey conducted in 2011, 2015, and 2018. A Monte Carlo simulation was used to estimate dietary cadmium exposure levels for Chongqing residents during three time periods: 2012–2014, 2015–2018, and 2019–2022. The health risks associated with these exposure levels were then assessed.

Results Cadmium was detected in 5 143 (55.79%) of all samples at levels ranging from 0.015 6 to 0.024 7 mg/kg. For Chongqing residents during 2012–2014, 2015–2018, and 2019–2022, the estimated mean dietary cadmium intake (µg/kg bw/month) was 12.69, 13.47, and 11.19 with MB substitutions for the left-censored food sample measurements used in the estimates) and 12.87, 13.62, and 12.42 (with UB substitutions for the left-censored food sample measurements used in the estimates), respectively. All these values were below the provisional tolerable monthly intake (PTMI) of 25 µg/kg bw/month established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The estimated mean dietary cadmium intake (µg/kg bw/month) for the highly exposed population (95 th percentile) during 2012–2014, 2015–2018, and 2019–2022 was 40.53, 39.42, and 34.53 (with MB) and 40.47, 38.43, and 36.63 (with UB), respectively, which was 1.62, 1.58, and 1.38 times the PTMI. Rice and rice products were the main source of dietary cadmium exposure risk in all periods, contributing 52.45% (with MB) and 51.87% (with UB) of total dietary cadmium exposure in 2012–2014, 65.42% (with MB) and 62.13% (with UB) in 2015–2018, and 47.54% (with MB) and 42.88% (with UB) in 2019–2022. Leafy vegetables were the second largest contributor, accounting for 23.86% (with MB) and 23.39% (with UB) of total dietary cadmium exposure in 2012–2014, 15.12% (with MB) and 14.21% (with UB) in 2015–2018, and 29.98% (with MB) and 37.12% (with UB) in 2019–2022.

Conclusions Dietary cadmium exposure among Chongqing residents from 2012 to 2022 was relatively low, posing a minimal health risk to the general population. However, the high-exposure population may face some health risks from dietary cadmium exposure. Rice and rice products, and leafy vegetables were identified as the main sources of risk from dietary cadmium exposure.