An Assessment of Dietary Exposure to Cadmium in Residents of Guangzhou, China

Probabilistic risk assessment of dietary exposure to lead in residents of Guangzhou, China

Lead and its compounds can have cumulative harmful effects on the nervous, cardiovascular, and other systems, and especially affect the brain development of children. We collected 4918 samples from 15 food categories in 11 districts of Guangzhou, China, from 2017 to 2022, to investigate the extent of lead contamination in commercial foods and assess the health risk from dietary lead intake of the residents. Lead was measured in the samples using inductively coupled plasma mass spectrometry. Dietary exposure to lead was calculated based on the food consumption survey of Guangzhou residents in 2011, and the health risk of the population was evaluated using the margin of exposure (MOE) method. Lead was detected in 76.5% of the overall samples, with an average lead content of 29.4 µg kg-1. The highest lead level was found in bivalves. The mean daily dietary lead intakes were as follows: 0.44, 0.34, 0.25, and 0.28 µg kg-1 body weight (bw) day-1 for groups aged 3-6, 7-17, 18-59, and ≥ 60 years, respectively. Rice and rice products, leafy vegetables, and wheat flour and wheat products were identified as the primary sources of dietary lead exposure, accounting for 73.1%. The MOE values demonstrated the following tendency: younger age groups had lower MOEs, and 95% confidence ranges for the groups aged 3-6 and 7-17 began at 0.6 and 0.7, respectively, indicating the potential health risk of children, while those for other age groups were all above 1.0. Continued efforts are needed to reduce dietary lead exposure in Guangzhou.

Physiological and molecular mechanisms of boron in alleviating cadmium toxicity in Capsicum annuum

Soil cadmium (Cd) contamination threatens food safety and human health, particularly in developing countries. Previously, we have proposed that boron (B) could reduce Cd uptake and accumulation in hot peppers (Capsicum annuum) by regulating the expression of genes related to Cd transport in roots. However, only few studies have examined the role of B in plant leaves under Cd stress. It is unclear how B induces the expression of relevant genes and metabolites in hot pepper leaves and to what extent B is involved in leaf growth and Cd accumulation. The purpose of this study was to investigate the effects of B on growth and Cd accumulation in hot pepper leaves by determining physiological parameters and transcriptome sequencing. The results showed that B application significantly improved the concentration of chlorophyll a and intercellular CO2, stomatal conductance, and photosynthetic and transpiration rates by 18-41 % in Cd-stressed plants. Moreover, B enhanced Cd retention in the cell wall by upregulating the expression levels of pectin-, lignin-, and callose-related genes and improving the activity of pectin methylesterase by 30 %, resulting in an approximate 31 % increase in Cd retention in the cell wall. Furthermore, B application not only enhanced the expression levels of genes related to antioxidant enzymes (superoxide dismutase, catalase, and peroxidase) and their activities by 28-40 %, thereby counteracting Cd-induced oxidative stress, but also improved Cd chelation, sequestration, and exclusion by upregulating the expression levels of genes related to sulfur metabolism, heavy metal-associated isoprenylated plant protein (HIPP), and transporters such as vacuolar cation/proton exchanger (CAX3), metal-nicotianamine transporter (YSL), ATP-binding cassette (ABC), zinc/iron transporters (ZIP) and oxic-compound detoxification (DTX), ultimately reinforcing Cd tolerance. Together, our results suggest that B application reduces the negative effects of Cd on leaf growth, promotes photosynthesis, and decreases Cd transfer to fruits through its sequestration and retention.

Burden of diabetes attributable to dietary cadmium exposure in adolescents and adults in China

At present, the health risk assessment of cadmium exposure has become a major focus of environmental health research. However, there is still a lack of systematic research on the burden of diabetes (DM) attributable to dietary cadmium exposure in adolescents and adults in China. Using the top-down method, the blood cadmium level (B-Cd) of Chinese adolescents and adults from 2001 to 2023 was combined with the relative risk (RR) of cadmium-induced diabetes to calculate the population attribution score (PAF). Subsequently, PAF was used to assess the disease burden (DB) of diabetes caused by cadmium exposure, expressed in disability adjusted life years (DALYs), and attribution analysis was carried out for cadmium exposure from different sources. The average blood cadmium concentration in Chinese adolescents and adults was 1.54 ± 1.13 µg/L, and the burden of DM attributable to cadmium exposure was 56.52 (44.81, 70.33) × 105 DALYs. The contribution rate of dietary cadmium exposure was 59.78%, and the burden of DM attributable to dietary cadmium exposure was 337.86 (267.85, 420.42) × 108 DALYs. In addition, the highest blood cadmium concentrations were found in Henan, Shanxi, and Jiangxi provinces, while the highest burden of DM attributable to cadmium exposure was found in Jiangsu, Henan, and Guangdong provinces. Cadmium exposure is a risk factor for DM, and we need to take comprehensive action to reduce the burden of DM attributable to dietary cadmium from health, economic, and social perspectives.

Occurrence and dietary exposure assessment of heavy metals in baby foods in the Kingdom of Saudi Arabia

Early childhood exposure to heavy metals like arsenic (As), cadmium (Cd), and lead (Pb) through baby foods unfolds many concerns about their toxic effects on growth and health. In this study, occurrence and dietary intake of As, Cd, and Pb in stage 1 infant formula (0-6 months), stage 2 infant formula (7-12 months), cereal-based meals, and biscuits were estimated. First, the levels of As, Cd, and Pb were determined with ICP-MS, followed by the calculation of estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) for As and Cd, and margin of exposure (MoE) for Pb. Mean levels of As, Cd, and Pb were the highest in cereal-based meals and biscuits as 15.5-11.1, 5.18-8.76, and 35.2-53.8 μg/kg, respectively. Newborns to 6 months old infants were estimated to be the highest exposed population to Cd and Pb (0.08 and 0.36 μg/kg bw/day), while infants aged 7-12 months old were exposed the highest to As. Based on the THQ, HI, and MoE findings, the current exposure levels from the selected baby foods to As, Cd, and Pb pose low potential chronic risks to both infant age groups. This research provides a roadmap for future investigations in chemical contaminants often detected in baby foods consumed regularly by Saudi infants.

Cadmium Exposure in Aquatic Products and Health Risk Classification Assessment in Residents of Zhejiang, China

Cadmium (Cd) pollution of food safety is a prominent food safety concern worldwide. The concentration of Cd in six aquatic food categories collected from 2018 to 2022 was analyzed using inductively coupled plasma mass spectrometry, and the Cd exposure levels were calculated by combining the Cd concentration and food consumption data of 18913 urban and rural residents in Zhejiang Province in 2015-2016. The mean Cd concentration was 0.699 mg/kg and the mean Cd exposure of aquatic foods was 0.00951 mg/kg BW/month for the general population. Marine crustaceans were the largest Cd contributor, corresponding to 82.7%. The regional distribution results showed that the average Cd exposure levels of 11 cities did not exceed the provisional tolerable monthly intake (PTMI). According to the subgroups, the Cd mean exposure level of 2-3-year-old children was significantly higher than that of the other age groups but did not exceed the PTMI. Health risk classification assessment demonstrated that the final risk score was six, and the health risk level of Cd exposure in aquatic products in the Zhejiang population was medium. These results demonstrated that the risk of Cd exposure in certain food types or age groups should be given more concern.

Multigenerational genetic effects of paternal cadmium exposure on ovarian granulosa cell apoptosis

To explore whether paternal cadmium (Cd) exposure causes ovarian granulosa cell (GC) apoptosis in offspring and the multigenerational genetic effects. From postnatal day 28 (PND28) until adulthood (PND56), SPF male Sprague-Dawley (SD) rats were gavaged daily with varying concentrations of CdCl_2. (0, 0.5, 2, and 8 mg/kg). After treatment, the F1 generation was produced by mating with untreated female rats, and the F1 generation male rats were mated with untreated female rats to produce the F2 generation. Apoptotic bodies (electron microscopy) and significantly higher apoptotic rates (flow cytometry) were observed in both F1 and F2 ovarian GCs following paternal Cd exposure. Moreover, the mRNA (qRTPCR) or protein (Western blotting) levels of bax, bcl2, bcl-xl, caspase 3, caspase 8, and caspase 9 were changed to varying degrees. Apoptosis-related miRNAs (qRTPCR) and methylation modifications of apoptosis-related genes (bisulfite-sequencing PCR) in ovarian GCs were further detected. Compared with those of controls, the expression patterns of miRNAs in F1 and F2 offspring were different after paternal Cd exposure, while the average methylation level of apoptosis-related genes did not change significantly (except for individual loci). In summary, there are paternal genetic intergenerational and transgenerational effects on ovarian GC apoptosis induced by paternal Cd exposure. These genetic effects were related to the upregulation of BAX, BCL-XL, Cle-CASPASE 3, and Cle-CASPASE 9 in F1 and the upregulation of Cle-CASPASE 3 in F2 progeny. Important changes in apoptosis-related miRNAs were also observed.

Current Levels of Environmental Exposure to Cadmium in Industrialized Countries as a Risk Factor for Kidney Damage in the General Population: A Comprehensive Review of Available Data

The growing number of reports indicating unfavorable outcomes for human health upon environmental exposure to cadmium (Cd) have focused attention on the threat to the general population posed by this heavy metal. The kidney is a target organ during chronic Cd intoxication. The aim of this article was to critically review the available literature on the impact of the current levels of environmental exposure to this xenobiotic in industrialized countries on the kidney, and to evaluate the associated risk of organ damage, including chronic kidney disease (CKD). Based on a comprehensive review of the available data, we recognized that the observed adverse effect levels (NOAELs) of Cd concentration in the blood and urine for clinically relevant kidney damage (glomerular dysfunction) are 0.18 μg/L and 0.27 μg/g creatinine, respectively, whereas the lowest observed adverse effect levels (LOAELs) are >0.18 μg/L and >0.27 μg/g creatinine, respectively, which are within the lower range of concentrations noted in inhabitants of industrialized countries. In conclusion, the current levels of environmental exposure to Cd may increase the risk of clinically relevant kidney damage, resulting in, or at least contributing to, the development of CKD.

Cadmium dietary exposure assessment in the adult population and pre-school children in the Republic of Serbia

Cadmium (Cd) is a toxic metal, present in all matrices of the environment and a common food contaminant. Human exposure to it may elicit many diverse health impairments. The aim of this study was to assess the dietary exposure to Cd for the adult population and preschool children in Serbia using probabilistic methodology. We measured Cd in 11,227 food samples belonging to 50 food items on the Serbian market. Cd was detected in 90% of the tested food items, and in 30.8% of the overall tested samples. The food item that contributed the most to total dietary Cd intake was potatoes (median Cd concentration of 7 ng/g) in adults, and fruit and vegetable juices in children (median Cd concentration of 19 ng/g). Weekly Cd intake shown as 50th and 95th percentiles were 2.54 and 4.74 µg/kg bw in the adult population, and 3.29 and 4.93 µg/kg bw in children. The results of this study are rather preliminary and should be considered as an indication of the need for further, more refined research, which would contribute to a more realistic risk assessment as a high-priority approach, especially in the case of vulnerable subpopulations such as children. Abbreviations: AT SDR: Agency for Toxic Substances and Disease Registry; EEA: European Environment Agency; EFSA: European Food Safety Authority; FAO/WHO: Food and Agriculture Organization/World Health Organization; HI: hazard index; IARC: International Agency for Research on Cancer; JECFA: Joint FAO/WHO Expert Committee on Food Additives; LOD: limit of detection; Cd: cadmium; TWI: tolerable weekly intake; UNEP: United Nations Environment Program; WI: weekly intake.

Probabilistic Risk Assessment of Dietary Exposure to Cadmium in Residents of Guangzhou, China-Young Children Potentially at a Health Risk

Cadmium (Cd) and its compounds are hazardous environmental pollutants with renal toxicity and human carcinogenicity, with ingestion of contaminated foods representing the major mode of exposure. There have been a number of reports evaluating the Cd content in various foods; however, regarding the actual risk posed by dietary cadmium exposure, only a few reports are available in which single point evaluation (less accurate than multiple point evaluation) was employed. In this study, we used a margin of exposure (MOE) model and @RISK software (for multiple evaluation) to evaluate Cd-related health risk in the local Guangzhou residents at varying ages, through a comparison between the estimated monthly exposures and the provisional tolerable monthly intake (0.025 mg/kg body weight (b.w.)), based on the Cd contents in various food categories available locally (a total of 3964 food samples were collected from each of the 13 districts of Guangzhou between 2015 and 2019), which were determined by using inductively coupled plasma mass spectrometry. In this study, Cd was detected in 69.6% of the samples (averaged 0.120 mg/kg), and rice and its products, leafy vegetables, bivalves, and shrimp and crabs contributed most to Cd exposure (8.63, 3.18, 2.79, and 1.48 ng/kg b.w./day, respectively). The MOE values demonstrated the following tendency: the younger age group, the lower MOE, and its 95% confidence range for the (youngest) 3~6 year old group started from 0.92, indicating a health risk of young children, while that for the other age groups were all above 1.0. Our preliminary findings warrant further clarification using biomarker assays in the relevant population.

Remediation of soil cadmium pollution by biomineralization using microbial-induced precipitation: a review

In recent years, with industrial pollution and the application of agricultural fertilizers with high cadmium (Cd) content, soil Cd pollution has become increasingly serious. A large amount of Cd is discharged into the environment, greatly endangering the stability of the ecological environment and human health. The use of microorganisms to induce Cd precipitation and mineralization is an important bioremediation method. Itis highly efficient, has a low cost, enables environmental protection, and convenient to operate. This article summarizes the pollution status, pollution source, biological toxicity and existing forms of Cd, as well as the biomineralization mechanism of microbial induced Cd(II) precipitation, mainly including microbial-induced carbonate precipitation, microbial-induced phosphate precipitation and microbial-induced sulfide precipitation. Factors affecting the bioremediation of Cd, such as pH, coexisting ions, and temperature, are introduced. Finally, the key points and difficulties of future microbe-induced Cd(II) biomineralization research are highlighted, providing a scientific basis and theoretical guidance for the application of microbe-induced Cd(II) immobilization in soil.

Health risk assessment of total exposure from cadmium in South China

Heavy metal pollution and hazards are a global major concern. Heavy metals can be directly or indirectly harmful to humans through ingestion, inhalation, and deraml. According to the literature survey, cadmium (Cd) total exposure assessment and health risk assessment were performed in a population group from South China. Results showed that the Cd contents in PM_2.5 and vegetables exceeded national standard limits. The same sources of Cd pollution contributed to different media; the main sources were artificial industrial activities such as electroplating, mining and smelting. The average daily dose of Cd via ingestion exceeded the provisional tolerable monthly intake proposed by the Joint Expert Committee on Food Additives (JECFA). Multimedia exposure via all three pathways followed the order 0-5-year-old children (3.26 × 10^-3 mg kg^-1·d^-1)>6-17-year-old children (1.46 × 10^-3 mg kg^-1·d^-1)>adults (1.18 × 10^-3 mg kg^-1·d^-1). The exposure from point source pollution was quite different from the results for nonpoint sources. Ingestion was the exposure pathway that contributes the largest proportion of multipathway and multimedia total exposure, accounting for over 99% of the total exposure in different populations. Staple foods, vegetables and meat were the three main exposure media for ingestion. The hazard quotients of multipathway and multimedia exposure to Cd in different populations were 5.57, 2.87 and 2.26, respectively, all at unacceptable risk levels. This study highlights the importance of multipathway and multimedia in the health risk assessment of heavy metal exposure in South China, and provides risk management measures to reduce noncarcinogenic health risks.

Dietary Lead Exposure and Associated Health Risks in Guangzhou, China

Lead exposure is associated with a wide range of adverse effects on human health. The principal exposure route in the general population is through the diet. In this study, we estimate the dietary lead intake and associated health risks among the residents of Guangzhou, China. Data on lead concentrations were derived from the food safety risk monitoring system, which included 6339 samples from 27 food categories collected in 2014–2017. Food consumption data were taken from a 2011 dietary survey of 2960 Guangzhou residents from 998 households. Dietary lead intake was estimated by age group (3–6, 7–17, 18–59, and ≥60 years), and relevant health risks were assessed using the margin of exposure (MOE) method. The mean and 95th percentiles (P95) of dietary lead intake were respectively 0.7466 and 2.4525 μg/kg body weight per day for preschool children aged 3–6 years; 0.4739 and 1.5522 μg/kg bw/day for school children aged 7–17 years; 0.3759 and 1.1832 μg/kg bw/day for adults aged 18–59 years; and 0.4031 and 1.3589 μg/kg bw/day for adults aged ≥60 years. The MOE value was less than 1 for preschool children at the mean exposure level and for all age groups at the P95 exposure level. Rice and its products, leafy vegetables, and wheat flour and its products were found to be the primary food sources of lead exposure. Our findings suggest that the health risk from dietary lead exposure is low for Guangzhou residents overall, but that young children and consumers of certain foods may be at increased risk. Continued efforts are needed to reduce the dietary lead exposure in Guangzhou.

Risk assessment for potentially toxic metal(loid)s in potatoes in the indigenous zinc smelting area of northwestern Guizhou Province, China

We investigated potentially toxic metal (loid)s (arsenic, As; cadmium, Cd; chromium, Cr; copper, Cu; mercury, Hg; lead, Pb; selenium, Se; and zinc, Zn) in agricultural samples (i.e., Solanum tuberosum L. tubers (potatoes) and their planting media) in the indigenous zinc smelting area of northwestern Guizhou Province, China. Based on the pollution index values for As, Cd, Pb and Zn, the order of the samples was as follow: slag > planting soil with slag > planting soil without slag, and the order of the samples in terms of the bioconcentration factor was the opposite. Cr, Cu and Hg were present in the planting soil with and without slag at slight pollution levels, and the other potentially toxic metal (loid)s had different degrees of contamination. Additionally, the potentially toxic metal (loid) contents in potato were under their limit values except for Cd (all samples) and Pb and Se (some samples). All bioconcentration factors for potatoes were below 0.5, and no health risk index value for potatoes was higher than 0.1. Therefore, although no significant health risk associated with potentially toxic metal (loid)s via consuming potato exists for either adult men or women in the research area, the Cd concentration in this crop should be monitored.