Cadmium (Cd) is a toxic and carcinogenic pollutant widely distributed in the environment. Dietary intake is the main source of Cd exposure for the nonsmoking population. Assessment of dietary Cd intake provides a pathway to predict Cd body burden and potential health effects. Kidney has been considered as the most sensitive target of chronic Cd exposure. Because of the proportional relationship between Cd accumulation in kidney and Cd excretion via urine, urinary Cd (UCd) has been used as a biomarker of Cd exposure. Here, we review the dietary Cd intake levels in different countries, summarize the global food Cd concentrations reported in both market basket and field surveys, discuss UCd levels among different populations, and illustrate the associations between dietary Cd intake and UCd levels in population-based studies. Recommendations for the prevention and reduction of Cd exposure through anthropogenic inputs and the food chain are also proposed. This review presents a worldwide overview of Cd exposure status through diet for the general population as well as those living in contaminated areas, and provides evidence for policy makers to protect humans from Cd exposure and related health effects. Graphical Abstract

Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences. Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences.

Ingestion of metal-contaminated soils poses risks to human health. To accurately assess the risks, in vitro assays have been developed to measure metal bioaccessibility. However, they often differ considerably in gastrointestinal fluid components and assay parameters, leading to inconsistent bioaccessibility results. As such, in vitro assays need to be validated against in vivo bioassays based on in vivo-in vitro correlations (IVIVCs). To help researchers to select the best in vitro assay and increase the robustness of the IVIVCs, there is a need to review and compile existing data. In this review, we focus on three metals (As, Pb, and Cd), five common in vitro assays (SBRC, UBM, IVG, DIN, and PBET), and two in vivo bioassays (mouse and swine models). Specifically, we 1) discuss variations in metal bioaccessibility measurements among different in vitro assays, 2) identify the roles of major gastrointestinal fluid constitutes and assay parameters in affecting metal bioaccessibility, 3) summarize weaknesses associated with existing IVIVCs, and 4) establish new IVIVCs using pooled soil samples from different studies. In addition, future research directions are highlighted, including better understanding of the roles of gastrointestinal fluid components, improving in vitro assays to better correlate with in vivo bioassays, expanding bioaccessibility measurements using different in vitro assays, validation of IVIVCs using independent soils, assessing the reliability of in vitro assays in remediated soils, and addressing the mechanisms behind IVIVCs.

Purpose of Review: Exposure to toxic metals/metalloids, such as arsenic (As), cadmium (Cd), and lead (Pb), through food consumption is a global public health concern. This review examines the contamination status of these metals/metalloids in food, assesses dietary intake across different populations, and proposes strategies to reduce metal/metalloid exposures throughout the food chain. Recent Findings: For the general population, dietary intake of metals/metalloids is generally lower than health-based guidance values. However, for vulnerable populations, such as infants, children, and pregnant women, their dietary intake levels are close to or even higher than the guidance values. Among different food categories, seafood shows higher total As, but largely present as organic species. Rice accumulates higher As concentration than other cereals, with inorganic As (iAs) and dimethylarsinic acid (DMA) being the main As species. Methylated thioarsenate species, such as dimethylmonothioarsenate, have also been detected in rice. The distribution of iAs and DMA in rice shows geographical variation. Additionally, seafood and cocoa products generally contain more Cd than other food, but seafood consumption does not significantly increase in adverse health effects due to its high zinc and iron content. Compared to As and Cd, Pb concentrations in food are generally lower. To minimize the health risks of metal/metalloid exposure, several strategies are proposed. Summary: Food contamination with toxic metals/metalloids poses significant concerns for human health, particularly for vulnerable populations. This review provides scientific evidence and suggestions for policy makers to reduce human exposure of metals/metalloids via dietary intake.