Dietary exposure to total and inorganic arsenic in the United States, 2006–2008

Biomonitoring toxic and essential element accumulation in trout in the as pontes mine pit lake (NW Spain)

This study investigated the accumulation of toxic and essential elements in trout from a pit lake situated in the surroundings of the abandoned As Pontes de García Rodríguez lignite mine (NW Spain). The element concentrations were compared with those measured in fish from upstream of the River Eume and from a local fish farm. Liver and muscle samples from fish captured in the lake (n = 16), river (n = 14) and fish farm (n = 10) captured in March-April 2022 were acid digested and analyzed by ICP-MS. The mining activity in As Pontes was found to have significantly impacted the aquatic ecosystem. Concentrations of Cd, Ni, Co, and Cu in the livers of the lake fish were significantly higher than in the livers of the other groups of fish, probably due to run-off from the spoil heap reaching the lake. Similarly, higher concentrations of Al, Pb, and Hg were observed in the river trout, associated with coal combustion at a near thermal power plant. Despite these variations, toxic and essential elements in both the pit lake and river remained low, within water quality standards, and do not pose an immediate threat to aquatic life. Concentrations of the metals in the muscle of wild fish, although higher than in farmed fish, were within EU limits. The study findings highlight the value of fish as indicators of environmental exposure and emphasize the ongoing need to monitor the pit lake to assess the long-term impacts of mining activities on aquatic health. Examination of liver tissue proved to be particularly useful in the assessments, providing a precise reflection of metal exposure and serving as a valuable means of evaluating environmental contamination and ecosystem health.

Inorganic arsenic in aquatic products in Shenzhen, China from 2018 to 2024: Levels, temporal variation and health risk assessment

Aquatic products are a significant source of arsenic exposure, with inorganic arsenic (iAs) posing a significant risk to humans. This study assessed iAs levels in 1191 aquatic products from Shenzhen, China (2018-2024), and estimated health risks. Shellfish had lower mean iAs levels (0.01 mg/kg ∼ 0.07 mg/kg), while crab, fish, and shrimp had higher levels (0.04 mg/kg ∼ 0.06 mg/kg). The iAs levels in shellfish were stable from 2018 to 2024. Health risk assessments showed estimated daily intake values ranging from 0.01 μg/kg·bw/day to 0.39 μg/kg·bw/day, with children having the highest exposure. The target hazard quotient exceeded 1 for fish and shrimp in high-consumption scenarios for children, indicating potential non-carcinogenic risks. Cancer risk estimates surpassed acceptable thresholds, especially for children and adolescents, suggesting an increased cancer risk with high consumption. Authorities should strengthen surveillance of iAs in aquatic products, especially shellfish and shrimp, and enhance environmental monitoring in Shenzhen.

Microbiota-dependent in vivo biotransformation, accumulation, and excretion of arsenic from arsenobetaine-rich diet

Arsenobetaine (AB), a major organic arsenic (As) species in seafood, is regarded as safe by current regulatory assessments due to low toxicity and rapid unmodified urinary excretion. This notion has been challenged by reports of AB metabolism by intestinal bacteria in vitro and more recent evidence of in vivo AB metabolism in mice. However, these studies did not establish the causal role of intestinal bacteria in AB transformation in vivo. To address this, we employed gnotobiology and compared the biotransformation of As from naturally AB-rich rodent diet in mice that were either germ-free or colonized with gut microbiota of varying microbial diversity. Our results confirm the in vivo metabolism of AB in the intestine under chronic dietary exposure. The transformation of ingested As was dependent on the presence/absence and complexity of the gut microbiota. Notably, specific toxic As species were absent under germ-free condition. Furthermore, gut microbial colonization was linked to increased As accumulation in the intestinal lumen as well as systemically, along with delayed clearance from the body. These findings emphasize the mammalian gut microbiota as a critical factor in evaluating the safety of AB-accumulating seafoods.

Toxic Metals and Metalloids in Food: Current Status, Health Risks, and Mitigation Strategies

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. 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.

The Accumulation of Toxic Elements (Pb, Hg, Cd, As, and Cu) in Red Swamp Crayfish (Procambarus clarkii) in Qianjiang and the Associated Risks to Human Health

Due to rapidly expanding crayfish consumption worldwide, the food safety of red swamp crayfish (Procambarus clarkii) is of great concern. China is the largest consumer and producer of crayfish globally. As of yet, it is unknown whether the main crayfish production cities in China are within safe levels of toxic heavy metals and metalloids. For 16 consecutive years, Qianjiang city ranked first in China in processing export volumes of red swamp crayfish. This study presents a comprehensive analysis of the enrichment levels and associated health risks of the species in Qianjiang. In our research, samples of four crayfish tissues, including the head, hepatopancreas, gills, and muscles, were collected from 38 sampling sites distributed in Qianjiang to evaluate the concentration levels of five heavy metals (Pb, Hg, Cd, As, and Cu). The concentration levels of all five metals in muscle did not surpass the national standard. Furthermore, eight significant correlations have been found. For further in-depth assess risk of crayfish in Qianjiang, estimated daily intake (EDI), target hazard quotient (THQ), carcinogenic risk (CR), and estimated maximum allowable consumption rates (CR_mm) were evaluated in the abdomen muscle and hepatopancreas. The THQ values for each metal were found to be less than 1, while the CR values were below 10^-6. Additionally, the CR_mm for adults was determined to be 17.2 meals per month. These findings, based on the analysis of five metallic elements included in this study, suggest that the consumption of crayfish abdomen muscle in Qianjiang does not pose any significant health risks. However, it is noteworthy that certain regions exhibit elevated levels of arsenic in the hepatopancreas, surpassing the national standard, thereby rendering them unsuitable for excessive consumption. In general, the findings can be used to provide guidance for safe dietary practices in China.

Consumer health risk assessment of Arsenic and Mercury in hen eggs through Monte Carlo simulations

BACKGROUND

This study was conducted to assess the concentration of heavy metals (arsenic and mercury) and estimate the probability that consumption of hen egg products collected in Iran has carcinogenic or non-carcinogenic consequences.

METHODS

A total of eighty-four hen eggs from 21 major brands were randomly selected from among thirty local supermarkets in two seasons (winter (January) and summer (August) 2022). Arsenic (As) and Mercury (Hg) was determined by using ICP-MS. The human health risk assessment refers to the formulation of the USEPA standard focused on Estimated Daily Intake (EDI), International Lifetime Cancer Risk (ILCR), Target Hazard Quotient (THQ), and Monte Carlo simulation (MCS) as a probabilistic method. Data analysis was carried out using the statistical software SPSS. Differences in mean concentrations of As and Hg in two seasons were tested by paired t-test.

RESULTS

Over two seasons, the average As and Hg concentrations in hen eggs were 0.79 and 0.18 µg.kg^-1, respectively. Seasonal difference in As concentration (p = 0.451) was not significant, whereas that of Hg concentration (p < 0.001) was significant. The calculated value of EDI was 0.29 µg As/day and 0.06 µg Hg/day. The EWI in the maximum scenario of as level in hen eggs was estimated to be 8.71 µg As and 1.89 µg Hg/month for Iranian adults. THQ's mean for As and Hg in adults was determined to be 0.00385 and 0.00066, respectively. In addition, ILCRs by MCS for As were 4.35E-4.

CONCLUSION

In total, the result indicates that there was not a significant risk of developing cancer; the calculation of THQ was still below the accepted level of 1, indicating that there was no risk while, according to most regulatory programs (ILCR > 10^- 4) shows a threshold carcinogenic risk of arsenic through consuming in hen eggs. Therefore, policymakers need to be aware that it is prohibited to establish chicken farms in heavily polluted urban areas. It is essential to regularly conduct examinations to measure the presence of heavy metals in both ground waters used for agriculture and the feed provided to chickens. Additionally, it is advisable to focus on raising public awareness about the importance of maintaining a healthy diet.

Pre-pregnancy exposure to arsenic in diet and non-cardiac birth defects

OBJECTIVES

To explore associations between maternal pre-pregnancy exposure to arsenic in diet and non-cardiac birth defects.

DESIGN

This is a population-based, case-control study using maternal responses to a dietary assessment and published arsenic concentration estimates in food items to calculate average daily total and inorganic arsenic exposure during the year before pregnancy. Assigning tertiles of total and inorganic arsenic exposure, logistic regression analysis was used to estimate OR for middle and high tertiles, compared to the low tertile.

SETTING

US National Birth Defects Prevention Study, 1997-2011.

PARTICIPANTS

Mothers of 10 446 children without birth defects and 14 408 children diagnosed with a non-cardiac birth defect.

RESULTS

Maternal exposure to total dietary arsenic in the middle and high tertiles was associated with a threefold increase in cloacal exstrophy, with weak positive associations (1·2-1·5) observed either in both tertiles (intercalary limb deficiency) or the high tertile only (encephalocele, glaucoma/anterior chamber defects and bladder exstrophy). Maternal exposure to inorganic arsenic showed mostly weak, positive associations in both tertiles (colonic atresia/stenosis, oesophageal atresia, bilateral renal agenesis/hypoplasia, hypospadias, cloacal exstrophy and gastroschisis), or the high (glaucoma/anterior chamber defects, choanal atresia and intestinal atresia stenosis) or middle (encephalocele, intercalary limb deficiency and transverse limb deficiency) tertiles only. The remaining associations estimated were near the null or inverse.

CONCLUSIONS

This exploration of arsenic in diet and non-cardiac birth defects produced several positive, but mostly weak associations. Limitations in exposure assessment may have resulted in exposure misclassification. Continued research with improved exposure assessment is recommended to identify if these associations are true signals or chance findings.

Assessment of cause-specific mortality and disability-adjusted life years (DALYs) induced by exposure to inorganic arsenic through drinking water and foodstuffs in Iran

The health risk and burden of disease induced by exposure to inorganic arsenic (iAs) through drinking water and foodstuffs in Iran were assessed. The iAs levels in drinking water and foodstuffs (15 food groups) in the country were determined through systematic review of three international databases (PubMed, Scopus, and Web of Science) and meta-analysis. Based on the results of the systematic review and meta-analysis, the average iAs levels in drinking water and all the food groups at the national level were lower than the maximum permissible levels. The total average non-carcinogenic risk of dietary exposure to iAs in terms of hazard index (HI) was 3.4. The average incremental lifetime cancer risk (ILCR) values of dietary exposure to iAs were determined to be 1.5 × 10^-3 for skin cancer, 1.0 × 10^-3 for lung cancer, and 4.0 × 10^-4 for bladder cancer. Over two-thirds of the non-carcinogenic and carcinogenic risk of dietary exposure to iAs was attributed to bread and cereals, drinking water, and rice. The total annual cancer incidence, deaths, disability-adjusted life years (DALYs), death rate, and DALY rate (per 100,000 people) were assessed to be 3347 (95 % uncertainty interval: 1791 to 5999), 1302 (697 to 2336), 72,606 (38,833 to 130,228), 1.6 (0.87 to 2.9), and 91 (49 to 160). The contribution of mortality in the attributable burden of disease was 95.1 %. The contributions of the causes in the attributable burden of disease were 72 % for lung cancer, 16 % for bladder cancer, and 12 % for skin cancer. Due to the significant attributable burden of disease, national and subnational action plans consisting of multi-disciplinary approaches for risk management of dietary exposure to iAs, especially for the higher arsenic-affected areas and high-risk population groups in the country are recommended.

Heterozygous disruption of beclin 1 alleviates neurotoxicity induced by sub-chronic exposure of arsenite in mice

Arsenite is a well-documented neurotoxicant that widely exists in the environment. However, the detailed mechanisms of arsenite neurotoxicity are not fully clarified. Autophagy has been reported to be involved in many neurological problems induced by arsenite. Since beclin 1 is an essential mediator of autophagy, we herein used both adult wild-type (beclin 1^+/+) and heterozygous disruption of beclin 1 (beclin 1^+/-) mice for chronic administration of 50 mg/L arsenite via drinking water for 3 months. Our results demonstrated that exposure of arsenite caused the working memory deficit, anxiety-like behavior and motor coordination disorder in beclin 1^+/+ mice, accompanied with pathological changes in morphology and electrophysiology in the cortical tissues. This treatment of arsenite significantly reduced the number of neuronal cells and induced microglia activation and synaptic transmission disorders in the wild-type mice as compared with vehicle controls. Intriguingly, by using beclin 1^+/- mice, we found that heterozygous disruption of beclin 1 profoundly attenuated these neurotoxic effects induced by arsenite, mainly manifested by improvements in the neurobehavioral impairments, abnormal electrophysiologic alterations as well as dysregulation of synaptic transmission. These findings together indicate that regulation of autophagy via beclin 1 would be a potential strategy for treatment against arsenite neurotoxicity.

Macroelements and toxic trace elements in muscle and liver of fish species from the largest three reservoirs in Turkey and human risk assessment based on the worst-case scenarios

Macroelement (Na, K, Ca, Mg and P) and toxic trace element (As, Cd and Pb) contents were investigated in muscle and liver of the two fish species (common carp and trout barb) from the largest three reservoirs (Atatürk, Keban and Karakaya) in Turkey. Also, human health risks for consumers using the worst-case scenarios were assessed. Potassium was the most abundant macroelement in muscle of both fish species in all reservoirs, whereas phosphorus was the most abundant in liver. Toxic trace element contents in the liver of the two fish species from the three reservoirs were higher than those in muscle. The mean levels of As and Pb in muscle and liver of fish species from the Karakaya Reservoir were higher than those from the other two reservoirs. Three-way ANOVA showed that the interaction between fish species, reservoir and fish tissue was significant for only Cd (p < 0.01). The maximum levels of As, Cd and Pb in muscle and liver of fish species from the three reservoirs were below permissible limits. The estimated daily intakes of toxic trace elements in fish species were much lower than their corresponding tolerable daily intakes. The target hazard quotient (THQ) and total THQ values in fish species were below 1, which indicated that non-carcinogenic health effects are not expected. The carcinogenic risk values for inorganic arsenic were within acceptable range. The results revealed that toxic trace elements in common carp and trout barb from the Atatürk, Keban and Karakaya reservoirs do not pose a significant health risk to consumers.

Pre-pregnancy dietary arsenic consumption among women in the United States

BACKGROUND

Arsenic is associated with several adverse health outcomes, including some birth defects. Although diet is the predominant route of arsenic exposure in the United States (U.S.), limited data exist regarding pre-pregnancy dietary arsenic consumption among U.S. women.

METHODS

Using data collected in the National Birth Defects Prevention Study (NBDPS), we estimated daily dietary arsenic consumption during the year before pregnancy for 10,886 mothers of nonmalformed control children delivered from 1997-2011. Responses to the NBDPS dietary assessment and food item estimates of total and inorganic arsenic were used to estimate consumption. Associations between total and inorganic arsenic consumption and selected maternal characteristics were estimated using multinomial logistic regression.

RESULTS

Estimates of mean maternal total and inorganic dietary arsenic consumption were 14.9 and 5.2 μg/day, respectively. Several positive and inverse associations with confidence intervals that excluded the null were observed. Comparing mothers in the middle or high total arsenic consumption tertiles to those in the low tertile, we observed positive associations (odds ratios = 1.3-3.8) for maternal age (≥30 years), lower (0-8 years) or higher (>12 years) education, race/ethnicity (non-Hispanic Black, Hispanic, other), and early pregnancy drinking with no binge episodes, and inverse associations (odds ratios = 0.4-0.8) for age (<25 years), body mass index (≥30.0 kg/m2 ), and early pregnancy smoking. Findings tended to be similar for inorganic arsenic consumption.

CONCLUSIONS

These contemporary estimates of pre-pregnancy dietary arsenic consumption among U.S. women show associations between both total and inorganic dietary arsenic consumption and several maternal characteristics, improving characterization of the public health impact of this exposure.

Lifetime excess cancer risk due to carcinogens in food and beverages: Urban versus rural differences in Canada

OBJECTIVES

To explore differences in urban versus rural lifetime excess risk of cancer from five specific contaminants found in food and beverages.

METHODS

Probable contaminant intake is estimated using Monte Carlo simulations of contaminant concentrations in combination with dietary patterns. Contaminant concentrations for arsenic, benzene, lead, polychlorinated biphenyls (PCBs) and tetrachloroethylene (PERC) were derived from government dietary studies. The dietary patterns of 34 944 Canadians from 10 provinces were available from Health Canada's Canadian Community Health Survey, Cycle 2.2, Nutrition (2004). Associated lifetime excess cancer risk (LECR) was subsequently calculated from the results of the simulations.

RESULTS

In the calculation of LECR from food and beverages for the five selected substances, two (lead and PERC) were shown to have excess risk below 10 per million; whereas for the remaining three (arsenic, benzene and PCBs), it was shown that at least 50% of the population were above 10 per million excess cancers. Arsenic residues, ingested via rice and rice cereal, registered the greatest disparity between urban and rural intake, with LECR per million levels well above 1000 per million at the upper bound. The majority of PCBs ingestion comes from meat, with values slightly higher for urban populations and LECR per million estimates between 50 and 400. Drinking water is the primary contributor of benzene intake in both urban and rural populations, with LECR per million estimates of 35 extra cancers in the top 1% of sampled population.

CONCLUSION

Overall, there are few disparities between urban and rural lifetime excess cancer risk from contaminants found in food and beverages. Estimates could be improved with more complete Canadian dietary intake and concentration data in support of detailed exposure assessments in estimating LECR.

Arsenic alters transcriptional responses to Pseudomonas aeruginosa infection and decreases antimicrobial defense of human airway epithelial cells

Arsenic contamination of drinking water and food threatens the health of hundreds of millions of people worldwide by increasing the risk of numerous diseases. Arsenic exposure has been associated with infectious lung disease in epidemiological studies, but it is not yet understood how ingestion of low levels of arsenic increases susceptibility to bacterial infection. Accordingly, the goal of this study was to examine the effect of arsenic on gene expression in primary human bronchial epithelial (HBE) cells and to determine if arsenic altered epithelial cell responses to Pseudomonas aeruginosa, an opportunistic pathogen. Bronchial epithelial cells line the airway surface, providing a physical barrier and serving critical roles in antimicrobial defense and signaling to professional immune cells. We used RNA-seq to define the transcriptional response of HBE cells to Pseudomonas aeruginosa, and investigated how arsenic affected HBE gene networks in the presence and absence of the bacterial challenge. Environmentally relevant levels of arsenic significantly changed the expression of genes involved in cellular redox homeostasis and host defense to bacterial infection, and decreased genes that code for secreted antimicrobial factors such as lysozyme. Using pathway analysis, we identified Sox4 and Nrf2-regulated gene networks that are predicted to mediate the arsenic-induced decrease in lysozyme secretion. In addition, we demonstrated that arsenic decreased lysozyme in the airway surface liquid, resulting in reduced lysis of Microccocus luteus. Thus, arsenic alters the expression of genes and proteins in innate host defense pathways, thereby decreasing the ability of the lung epithelium to fight bacterial infection.