Chronic dietary exposure to total arsenic, inorganic arsenic and water-soluble organic arsenic species based on results of the first German total diet study

Feasible approaches for arsenic speciation analysis in foods for dietary exposure assessment: a review

Arsenic (As) occurs naturally in different forms and oxidation states. Amongst them, inorganic arsenic (iAs) is classified as both genotoxic and carcinogenic whilst other organic arsenic species are considered less toxic. As in rice is mainly present in the form of iAs which therefore poses a health risk to populations that consume rice as a staple food. In 2011, the Joint Food and Agriculture Organisation/World Health Organisation Expert Committee on Food Additives determined the iAs benchmark dose lower confidence limit for a 0.5% increased incidence of lung cancer in humans (BMDL0.5) which computed to be 3.0 μg/kg body weight (bw)/day. However, the European Food Safety Authority (EFSA) has recently lowered the BMDL0.5 of iAs to 0.06 μg iAs/kg bw per day based on a low risk of bias case-control/cohort study on skin cancer as a Reference Point (RP). Subsequently, EFSA established a BMDL10 of 18.2 mg monomethylarsenic (V) (MMA(V))/kg bw/day and 1.1 mg dimethylarsenic (V) (DMA(V))/kg bw/day as RPs with reference to studies on skin cancer and urinary bladder tumours in rats respectively. Therefore, As speciation is essential when conducting dietary exposure assessment. Recent studies showed thiolated counterparts of MMA and DMA were found in certain foodstuffs, especially grain. However, these thiolated As species were not recognised in acidic, basic or peroxide systems as they transformed to MMA and DMA in these extractants. Therefore, one of the objectives of this review was to assess whether published analytical methods are fit for As speciation analysis, especially for iAs, MMA and DMA, in foodstuffs. Besides, discussion was conducted on whether limits of detection are sufficiently low for dietary exposure assessment with respect to recently established RPs of iAs, MMA and DMA when an upper bound approach is applied. Moreover, possible future research gaps are identified based on current knowledge and existing literature.

A comprehensive review on arsenic exposure and risk assessment in infants and young children diets: Health implications and mitigation interventions in a global perspective

The early stages of human development are critical for growth, and exposure to arsenic, particularly through the placenta and dietary sources, poses significant health risks. Despite extensive research, significant gaps remain in our comprehension of regional disparities in arsenic exposure and its cumulative impacts during these developmental stages. We hypothesize that infants in certain regions are at greater risk of arsenic exposure and its associated health complications. This review aims to fill these gaps by providing a comprehensive synthesis of epidemiological evidence related to arsenic exposure during early life, with an emphasis on the underlying mechanisms of arsenic toxicity that contribute to adverse health outcomes, including neurodevelopmental impairments, immune dysfunction, cardiovascular diseases, and cancer. Further, by systematically comparing dietary arsenic exposure in infants across Asia, the Americas, and Europe, our findings reveal that infants in Bangladesh, Pakistan, and India, exposed to levels significantly exceeding the health reference value range of 0.3-8 µg/kg/day, are particularly vulnerable to dietary inorganic arsenic. This comparative analysis not only highlights geographic disparities in exposure but also underscores the variability in regulatory frameworks. Finally, the review identifies early life as a critical window for dietary arsenic exposure and offers evidence-based recommendations for mitigating arsenic contamination in infant foods. These strategies include improved agricultural practices, dietary modifications, stricter regulatory limits on arsenic in infant products, and encouragement of low-arsenic dietary alternatives. Our work establishes the framework for future research and policy development aimed at reducing the burden of arsenic exposure from source to table and effectively addressing this significant public health challenge.

Risk assessment of complex organoarsenic species in food

The European Commission asked EFSA for a risk assessment on complex organoarsenic species in food. They are typically found in marine foods and comprise mainly arsenobetaine (AsB), arsenosugars and arsenolipids. For AsB, no reference point (RP) could be derived because of insufficient toxicity data. AsB did not show adverse effects in the two available repeat dose toxicity tests in rodents. It has not shown genotoxicity in in vitro assays. There is no indication of an association with adverse outcomes in human studies. The highest 95th percentile exposure for AsB was observed in 'Toddlers' with an estimate of 12.5 μg As/kg bw per day (AsB expressed as elemental arsenic). There is sufficient evidence to conclude that AsB at current dietary exposure levels does not raise a health concern. For glycerol arsenosugar (AsSugOH) a RP of 0.85 mg As/kg bw per day was derived based on the BMDL10 values for cognitive and motor function in mice. A margin of exposure (MOE) of ≥ 1000 would not raise a health concern. The highest 95th percentile estimate of exposure for AsSugOH (for adult consumers of red seaweed Nori/Laver) was 0.71 μg As/kg bw per day (AsSugOH expressed as elemental arsenic), which results in an MOE > 1000, not raising a health concern. Based on qualitative consideration of all identified uncertainties, it is regarded likely that the dietary exposures to AsB and AsSugOH do not raise a health concern. No conclusions could be drawn regarding other arsenosugars. No risk characterisation could be conducted for arsenolipids, due to the lack of data.

Evaluation of groundwater quality with multi-source pollution based on source identification and health risks

Groundwater is a crucial water supply source in Chengdu City, western China, a region experiencing significant water scarcity. The sources of inorganic pollutants in groundwater and their potential health risks are of great concern. In this study, based on 156 groundwater samples collected in 2021 in the study area were analyzed for hydrochemical characterization and controlling factors. The Positive Matrix Factorization (PMF) model was used for contaminant source analysis, and Monte Carlo Simulation (MCS) combined with the Health Risk Evaluation Model (HREM) was used to quantify the health risks. The results indicate that the groundwater in the study area is predominantly of the Ca·Na-SO4·HCO3, Ca·Na-HCO3·SO4 and Ca-HCO3·SO4 types, mainly influenced by the combination of evaporation-concentration-crystallization and rock leaching-weathering. K+, Na+, and Cl- mainly originate from the weathering and dissolution of potassium feldspar and rock salt, while Ca2+, Mg2+, HCO3-, and SO42- primarily come from the weathering and dissolution of sulfate minerals. The main sources of groundwater pollution and their contributions are as follows: domestic pollution (25.6 %), dissolution-filtration-evaporation-concentration action (22.8 %), hydrogeochemical evolution (15.8 %), water-rock interactions (12.8 %), primary geologic context (12.1 %), and agricultural non-point source pollution (11.0 %). Cl- and As are the primary contributors to non-carcinogenic and carcinogenic risks, respectively. Non-carcinogenic risks are below USEPA standards, while the average carcinogenic risk for arsenic exceeded the maximum acceptable risk level thresholds by 23 and 109 times for adults and children, respectively. Non-carcinogenic and carcinogenic health risks were mainly influenced by pollutant concentrations. The primary geological background and domestic pollution contributed the most to the non-carcinogenic risk for adults (50.3 %) and children (77.1 %), and 38.2 % and 10.3 %, respectively. This study highlights the necessity of establishing a comprehensive groundwater pollution monitoring system, enhancing industrial waste management practices, and raising public awareness to mitigate contamination and ensure the sustainable use of groundwater resources in Chengdu City.

Arsenic in Rice and Rice-Based Products with Regard to Consumer Health

Most articles on the exposure to arsenic (As) associated with rice and rice products come from Asia where these products are consumed in the largest quantities; relatively few of the articles have focused on European consumers. Since rice products can represent a significant contribution to overall arsenic exposure, the aim of the study was to determine the total arsenic content (tAs) in rice and the most commonly-consumed rice products available on the Polish market. The tAs determination was performed by hydride generation coupled to inductively-coupled plasma optical emission spectrometry (HG-ICP-OES). Because an inorganic form of As (iAs) is mutagenic and carcinogenic and about 100-fold more toxic than the organic form, an additional aim of the study was to assess the risk of its ingestion, assuming that it constitutes 67.7%, 72.7%, or 90% of tAs. In all products tested, the calculated iAs content was below the maximum permissible levels, and no threat was found for any of the analyzed Polish consumers, based on the mean rice consumption in Poland and the mean calculated iAs content. However, a potential health risk was noted among infants and young children, assuming maximum iAs levels and threefold higher consumption (16.2 g d-1). To avoid a risk of developing cancer, infants up to one year of age should consume no more than 32.2 g of the studied products per week, children under three years of age up to 68.7 g, and adults 243 g. Consumers should strive to include a variety of cereals in their daily diet and choose products shown to have low arsenic contamination levels based on testing and inspection rankings.

Risk assessment of small organoarsenic species in food

The European Commission asked EFSA for a risk assessment on small organoarsenic species in food. For monomethylarsonic acid MMA(V), decreased body weight resulting from diarrhoea in rats was identified as the critical endpoint and a BMDL10 of 18.2 mg MMA(V)/kg body weight (bw) per day (equivalent to 9.7 mg As/kg bw per day) was calculated as a reference point (RP). For dimethylarsinic acid DMA(V), increased incidence in urinary bladder tumours in rats was identified as the critical endpoint. A BMDL10 of 1.1 mg DMA(V)/kg bw per day (equivalent to 0.6 mg As/kg bw per day) was calculated as an RP. For other small organoarsenic species, the toxicological data are insufficient to identify critical effects and RPs, and they could not be included in the risk assessment. For both MMA(V) and DMA(V), the toxicological database is incomplete and a margin of exposure (MOE) approach was applied for risk characterisation. The highest chronic dietary exposure to DMA(V) was estimated in 'Toddlers', with rice and fish meat as the main contributors across population groups. For MMA(V), the highest chronic dietary exposures were estimated for high consumers of fish meat and processed/preserved fish in 'Infants' and 'Elderly' age class, respectively. For MMA(V), an MOE of ≥ 500 was identified not to raise a health concern. For MMA(V), all MOEs were well above 500 for average and high consumers and thus do not raise a health concern. For DMA(V), an MOE of 10,000 was identified as of low health concern as it is genotoxic and carcinogenic, although the mechanisms of genotoxicity and its role in carcinogenicity of DMA(V) are not fully elucidated. For DMA(V), MOEs were below 10,000 in many cases across dietary surveys and age groups, in particular for some 95th percentile exposures. The Panel considers that this would raise a health concern.

Progress of photocatalytic oxidation-adsorption synergistic removal of organic arsenic in water

Photocatalytic oxidation-adsorption synergistic treatment of organic arsenic pollutants is a promising wastewater treatment technology, which not only degrades organic arsenic pollutants by photocatalytic degradation but also removes the generated inorganic arsenic by adsorption. This paper compares the results of photocatalytic oxidation-adsorption co-treatment of organic arsenic pollutants such as monomethylarsonic acid, dimethylarsinic acid, phenylarsonic acid, p-arsanilic acid, and 3-nitro-4-hydroxyphenylarsonic acid on titanium dioxide, goethite, zinc oxide, and copper oxide. It examines the influence of the morphology of organic arsenic molecules, pH, coexisting ions, and the role of natural organic matter. The photocatalytic oxidation-adsorption co-treatment mechanism is investigated, comparing the hydroxyl radical oxidation mechanism, the hydroxyl radical and superoxide anion radical cooxidation mechanism, and the hydroxyl radical and hole cooxidation mechanism. Finally, the future prospects of metal oxide photocatalytic materials and the development of robust and efficient technologies for removing organic arsenic are envisioned.

Coordination polymer gel mediated spectrophotometric, ICP-AES and spectrofluorimetric methods for trace As(III) determination in water and food samples

Herein, a coordination polymer gel is proposed for the determination of As(III) in real samples through multispectroscopic techniques viz. spectrophotometry, spectrofluorimetry, and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Taguchi L32 (46 21) design and adaptive neuro fuzzy inference system (ANFIS) optimized the controllable factors affecting the extraction yielding an experimental S/N ratio of 39.94 dB. The fluorescence quenching (KSV = 2.63 × 106 L mol-1) was static with photoelectron transfer being the main mechanism confirmed by the density functional theory calculations. The limits of detection (LODs), limits of quantification (LOQs) and linear ranges were 0.038 μg L-1, 0.13 μg L-1 and 1.67-116.67 μg L-1, 0.40 μg L-1, 1.21 μg L-1 and 1.67-33.33 μg L-1, 1.07 μg L-1, 3.24 μg L-1 and 3.32-35.37 μg L-1 for the developed enrichment coupled ICP-AES, spectrophotometry and fluorescence sensing methods. Among these methods, the enrichment - ICP-AES method has the lowest LOD, LOQ and the widest linear range followed by the enrichment - spectrophotometry and fluorescene sensing methods. Spectrofluorimetry offers high sensitivity, selectivity, and possible real time monitoring, spectrophotometry provides a cost-effective and versatile option, while ICP-AES manifests multi-element analysis with high sensitivity and low interference. The developed methods were validated and employed for the successful determination of trace As(III) in real samples. The employment of these methods enhances the overall analytical capability for a wide range of sample types and concentrations.

Solvent Extraction with Cyanex 923 to Remove Arsenic(V) from Solutions

The removal of harmful arsenic(V) from aqueous solutions using Cyanex 923 (solvation extractant) was investigated using various experimental variables: equilibration time, the acidity of the aqueous phase, temperature, extractant and arsenic concentrations, and O/A ratio. Cyanex 923 extracted As(V) (and sulfuric acid) from acidic solutions; however, it could not be used to remove the metal from slightly acid or neutral solutions. The extraction of arsenic is exothermic and responded to the formation of H3AsO4·nL species in the organic phase (L represents the extractant, and the stoichiometric factor, n = 1 or 2, depends on the acidity of the aqueous phase). Extraction isotherms are derived from the experimental results. Both arsenic and sulfuric acid loaded onto the organic phase can be stripped with water, and stripping isotherms are also derived from the experimental results. The selectivity of the system against the presence of other metals (Cu(II), Ni(II), Bi(III), and Sb(III)) is investigated, and the ability of Cyanex 923 to extract As(V) and sulfuric acid compared to the use of other P=O-based solvation reagents, such dibutyl butylphosphonate (DBBP) and tri-butyl phosphate (TBP), is also investigated.

Study of geochemical features of soils on the territory of an abandoned coal mining area using geoinformation technologies

The article describes the results of a study of the geochemical features of soils on the territory of an abandoned mining area. The Kizel coal basin (Russia) is of particular interest for studying the consequences of technogenic and post-technogenic transformation of the natural environment. The study of the soil as a deposit medium made it possible to identify geochemical indicators of the negative impact. Such a detailed study of the distribution of chemical elements in this area was conducted for the first time. Geoinformation system and maps with interpolation were created to study the spatial distribution of metals and metalloids in soils. Umbric Retisols Abruptic and Haplic Retisols Abruptic soils are common in the territory. Sampling for geochemical testing was carried out from two horizons: humus and podzolic. Sampling from two depths made it possible to identify elements that continue to be contaminated at the time of the study. A total of 103 sample plots were established in the study area. The results obtained were compared with the background of the natural region of the Western Urals to identify the contribution of technogenesis. As a result, the coefficients of concentration and dispersion of chemical elements were calculated. Due to this, elements were identified, the accumulation of which occurs on the territory of the Kizelovsky coal basin. To identify the current and accumulated pollution, the ratio between the humus and podzolic horizons was calculated. As a result, it was found that at the moment in the humus horizon in some areas there is a high accumulation of Co, Mn, Ni and Sr. The geochemical series of the territory for the humus and podzolic horizons was obtained: Fe > Ti > Mn > Sr > Cr > V > Zn > Ni > Co > Pb > As. Data on the geochemical specificity of the territory of the Kizel coal basin have been obtained. The created geoinformation database reflects the physical and chemical properties of soils, metals and metalloids content, dispersion and accumulation coefficients, coefficients of the ratio of the humus and podzolic horizon. Based on it, it is possible to obtain data on the geochemical features of the territory, geoecological characteristics, spatial distribution of metals and metalloids and identification of pollution sources. Co (24 ± 2.8 mg/kg), Mn (1100 ± 155 mg/kg), Ni (69 ± 9.3 mg/kg), As (10 ± 3.5 mg/kg), Cr (178 ± 20 mg/kg), Zn (80 ± 7.8 mg/kg) and Sr (221 ± 26 mg/kg) accumulate in the humus horizon. Co (24 ± 1.8 mg/kg), Mn (1000 ± 103 mg/kg), Ni (60 ± 6.4 mg/kg) and Cr (153 ± 15.2 mg/kg) accumulate in the podzolic horizon.

Toxicity Weighting for Human Biomonitoring Mixture Risk Assessment: A Proof of Concept

Chemical mixture risk assessment has, in the past, primarily focused on exposures quantified in the external environment. Assessing health risks using human biomonitoring (HBM) data provides information on the internal concentration, from which a dose can be derived, of chemicals to which human populations are exposed. This study describes a proof of concept for conducting mixture risk assessment with HBM data, using the population-representative German Environmental Survey (GerES) V as a case study. We first attempted to identify groups of correlated biomarkers (also known as 'communities', reflecting co-occurrence patterns of chemicals) using a network analysis approach (n = 515 individuals) on 51 chemical substances in urine. The underlying question is whether the combined body burden of multiple chemicals is of potential health concern. If so, subsequent questions are which chemicals and which co-occurrence patterns are driving the potential health risks. To address this, a biomonitoring hazard index was developed by summing over hazard quotients, where each biomarker concentration was weighted (divided) by the associated HBM health-based guidance value (HBM-HBGV, HBM value or equivalent). Altogether, for 17 out of the 51 substances, health-based guidance values were available. If the hazard index was higher than 1, then the community was considered of potential health concern and should be evaluated further. Overall, seven communities were identified in the GerES V data. Of the five mixture communities where a hazard index was calculated, the highest hazard community contained N-Acetyl-S-(2-carbamoyl-ethyl)cysteine (AAMA), but this was the only biomarker for which a guidance value was available. Of the other four communities, one included the phthalate metabolites mono-isobutyl phthalate (MiBP) and mono-n-butyl phthalate (MnBP) with high hazard quotients, which led to hazard indices that exceed the value of one in 5.8% of the participants included in the GerES V study. This biological index method can put forward communities of co-occurrence patterns of chemicals on a population level that need further assessment in toxicology or health effects studies. Future mixture risk assessment using HBM data will benefit from additional HBM health-based guidance values based on population studies. Additionally, accounting for different biomonitoring matrices would provide a wider range of exposures. Future hazard index analyses could also take a common mode of action approach, rather than the more agnostic and non-specific approach we have taken in this proof of concept.

Trace elements in aquatic products from Shenzhen, China and their implications for human exposure

Aquatic organisms in industrially polluted areas can accumulate large quantities of heavy metals. To assess the resulting health risks, 11 trace elements in 184 aquatic products representing 14 species of fish, crustaceans, and bivalves collected from Shenzhen, China were determined. Aluminum (Al), chromium (Cr), nickel (Ni), selenium (Se), antimony (Sb), manganese (Mn), copper (Cu), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were determined by inductively coupled plasma mass spectrometry. The pollution levels of each product and the human health risk resulting from their consumption were then assessed. The concentrations of As in 57 % of samples and Cd in 11 % of samples exceeded the upper limits stipulated by the Chinese National Food Safety Standards (GB 2762-2017), which was mainly due to high concentrations of trace elements in crustaceans and bivalves. The Nemerow integrated pollution index indicated that the aquatic products accumulated high levels of As and Cd. Health risk assessments using the target hazard quotient (THQ) and hazard index (HI) suggested that As and Cd exposure due to consumption of aquatic products presents a potential health risk for residents of Shenzhen.