Inorganic Arsenic Concentrations Research Articles

Carcinogenic risks of inorganic arsenic in white rice in Asia

This study estimated the incremental lifetime cancer risk (ILCR) of inorganic arsenic (iAs) from white rice ingestion in eight countries (China, Korea, Pakistan, Saudi Arabia, Thailand, Vietnam, Bangladesh, and Cambodia) in Asia by using data collected from published literature (n = 4857). ILCR of iAs exposure from white rice ingestion substantially varied with region, ranging from 0.37 to 13.46 per 10000 people, with an average of 6.12 per 10000 people. Bangladesh had the highest ILCR, followed by Cambodia, Vietnam, Thailand, China, Korea, Saudi Arabia, and Pakistan. Carcinogenic risks of iAs exposure from white rice ingestion in China, Korea, Thailand, Vietnam, Bangladesh, and Cambodia are at an unacceptable level (more than 1 per 10000 people). Linear regression analysis indicated that ingestion rate and inorganic arsenic content were the critical factors determining regional differences in carcinogenic risk of iAs exposure from white rice ingestion in Asia.

Effect of Three Foliar Inhibitors on Accumulation of Cd and As in Rice Grains

This study investigated the impact of single and combined applications of three foliar inhibitors on the accumulation of cadmium （Cd） and arsenic （As） in rice grains. Two rice varieties, Songyazao 1 （for early rice） and Wuxiang Youyue （for late rice）, were selected for this experiment. We established nine treatments using a pot experiment method, including a control （CK） treated with no foliar inhibitor and three individual foliar inhibitors： cysteine （L-Cys）, potassium sulfide （K2S）, and dipotassium hydrogen phosphate （K2HPO4）. We then combined the applications of two foliar inhibitors： L-Cys with low/high concentrations of K2S, L-Cys with low/high concentrations of K2HPO4, and K2S with a low concentration of K2HPO4. The results showed that the single and combined applications of foliar inhibitors reduced Cd and As concentrations in rice grains. The Cd content in brown rice treated with L-Cys and K2S/K2HPO4 was reduced below the standard limit for food safety of 0.20 mg·kg-1. Compared to the CK, the content of inorganic arsenic （IAs） in early and late rice decreased by 4.68%-56.75% and 2.84%-16.91%, respectively. Foliar inhibitors applied individually or in combinations facilitated the transport of Cd and As from the stem to the leaf while inhibiting their transport from the leaf to the rice grain. This resulted in the sequestration of Cd and As within the leaf cell wall, ultimately reducing the content of these elements in rice grains. Among the combination treatments, the application of L-Cys and high-concentration K2S achieved the best results. The Cd content in early and late rice decreased by 37.64% and 26.37%, respectively, falling below 0.20 mg·kg-1. The IAs content in early and late rice was reduced to 0.10 mg·kg-1 （below 0.20 mg·kg-1） and 0.24 mg·kg-1, respectively. This study provides a valuable theoretical foundation and empirical data to support the achievement of safe rice production practices.

Development of cost-effective inorganic arsenic extraction method for resource-limited regions: Analysis of efficiency and regulatory implications

This study evaluated the effectiveness of coke and lemonade extraction methods compared to the standard 1 % v/v HNO3 method for determining inorganic arsenic (iAs) concentrations in rice bran samples using a field-deployable method (Arsenator field kit). The limit of detection (LOD) for the methods was 45 μg kg−1, comparable to existing literature. The extraction efficiencies were assessed by comparing iAs recovery rates, with coke extraction yielding the highest recovery of 127.4 %, followed by lemonade at 116.2 %, and HNO3 at 100 %. Statistical analysis indicated strong correlations between the extraction methods, particularly between HNO3 and coke (Pearson correlation coefficient, 0.990), suggesting that coke extraction is a reliable alternative to the traditional HNO3 method. However, lemonade extraction showed a lower correlation (0.940) and higher false negative rates, indicating potential limitations for regulatory compliance. Notably, at the maximum contaminant limit (MCL) of 0.100 mg kg−1, coke extraction produced an 8 % false positive rate with no false negatives, while lemonade extraction had an 8 % false positive rate and a 17 % false negative rate. This study underscores the potential of coke extraction as a cost-effective and efficient alternative for assessing iAs levels in rice products, especially in resource-limited settings. Recommendations include the standardization of coke extraction protocols and the development of robust monitoring programs to ensure food safety and public health protection against arsenic contamination. Overall, the findings contribute valuable insights for improving arsenic detection methods and regulatory compliance in food safety practices.

Metal concentrations in fish, crabs, and bivalve molluscs from marine waters adjacent to a multi-metals smelter and refinery

Metal concentrations were determined in tissues of finfish, crabs, and bivalve molluscs collected from marine waters near Port Pirie, South Australia, the site of a long-standing multi-metals smelter and refinery. A general trend of tissue metal concentrations in order of highest to lowest was observed in bivalves > crabs > finfish. A lead concentration of 158 ± 6.6 mg/kg (wet wt.) was observed in blue mussels (Mytilus galloprovincialis) sampled close to the smelter. Lead concentrations correlated positively with proximity to the smelter in all biota analysed. Similar relationships were observed for cadmium, copper, zinc and selenium in all biota except razorfish (Pinna bicolor; Bivalvia: Pinnidae), which showed no correlation with proximity to the smelter for these metals. Inorganic arsenic concentrations were below the limit of reporting in the majority of the analysed samples, however inorganic arsenic concentrations in blue swimmer crabs (Portunus armatus) and blue mussels correlated with proximity to the smelter. Mercury concentrations in the biota analysed were generally low and showed variable relationships with proximity to the smelter, with no significant correlation observed in finfish and razorfish, a significant positive correlation in blue mussels, and a significant negative correlation in blue swimmer crabs. This is the first major study of metal concentrations in recreationally-targeted marine species near Port Pirie species for more than two decades. Comparison with data from previous studies conducted shows little change in tissue metal concentrations in marine biota near Port Pirie over the past 40 years.

Domestic fish for more versatile and safer consumption EU‐fish IV

Abstract Fish is an important part of nutrition and well‐being. The challenge of Finnish wild fish is contaminants which accumulate in some species in higher concentrations, partially limit the usability of the fish in the food/feed market and weaken the assessment of the state of the marine environment. The aim of this study was to obtain data on the amounts of nutrients and contaminants in domestic fish species that are commercially important or should be increased in use according to national plans. The aim was also to produce information for updating the national fish use recommendations. The concentrations of contaminants in Finnish fish were mostly below the maximum levels set by the EU. The trend of dioxin and PCB compound concentrations in the Baltic Sea has been declining since the 1980s, and the concentrations in Baltic herring appear to have settled around or below the maximum levels in all sea areas and size classes. The PFAS concentrations in the studied fish samples were within the maximum limits, except for Baltic herring in the Archipelago Sea and the Bothnian Sea. Additionally, the PFAS concentrations in Baltic herring rose quite sharply between 2009 and 2023. During the current study, PFAS concentrations in Baltic herring from the same sea area and size classes increased significantly from autumn 2022 to spring 2023. The seasonal trend was suspected to be related to the fish's diet, but factors affecting PFAS concentrations in fish, such as the impact of seasons and fitness (function of weight and size of the fish), need further investigation, and PFAS concentrations in Baltic herring should be monitored. PBDE concentrations in Finnish fish were found to be very low, although they exceeded the environmental quality standard. Mercury concentrations in fish, except for two samples, were lower than the maximum levels set by Commission Regulation (EU) 2023/915. The proportion of methylmercury in total mercury was 56–94% in different fish species. Inorganic arsenic concentrations in all fish samples were below the detection limit of 0.01 mg/kg. The highest concentrations of omega‐3 fatty acids were measured in Baltic herring and vendace. Fish caught from marine areas had higher vitamin D concentrations than those from inland waters, and there was significant variation in concentrations within fish species. With current food consumption and concentration data, the health benefits of fish consumption outweigh the health risks associated with contaminants in fish for all age groups. The greatest health benefits are seen in those over 45 years old, where fish consumption reduces the burden of diseases such as cardiovascular diseases and breast cancer, as well as overall mortality. On a national scale, the current use of domestic and imported fish is estimated to reduce the disease burden annually by nearly 70,000 disability‐adjusted life years (DALYs). As a conclusion, the health benefits of fish consumption outweigh the harms of contaminants in all age groups. Increasing the consumption of fish in accordance with nutritional recommendations would benefit the health of the population. For children and expectant or breastfeeding mothers, a diverse fish consumption is useful. The safe use recommendations of the Finnish Food Authority help this risk group to direct their fish consumption to fishing areas and fish species with the lowest amounts of contaminants.

A review of arsenic speciation in freshwater fish: Perspectives on monitoring approaches and analytical methods

Arsenic accumulation in fish poses concerns for subsistence and recreational fishers worldwide. However, the toxicity of arsenic to consumers strongly depends on the chemical forms, or species, present. Risk assessments often rely on total arsenic concentrations ([As]), adjusting for assumed small percentages of the most harmful inorganic species. While studies on arsenic speciation in marine fish are widespread, and commonly report less toxic arsenobetaine (AsB) as the dominant form, fewer studies have been conducted on freshwater fish, where arsenic speciation may be more variable. To assess these findings, we conducted a systematic literature review on arsenic speciation in freshwater fish using Covidence© review management software. From over 1100 screened studies, 41 were selected for inclusion based on predefined criteria. These studies reported highly variable arsenic speciation patterns in freshwater fish, calling into question the assumption that AsB is the dominant form present. Sites with suspected or known arsenic contamination issues were prominent, with >50% of data reviewed originating from a contaminated river or lake, but the effect of contamination on arsenic speciation was variable. Although AsB and other organic forms typically dominated, some studies (6/41; 15%) identified fish with elevated concentrations of inorganic arsenic (>1 mg/kg dry wt.), most often corresponding to over 20% of total arsenic. Furthermore, arsenic speciation results accounted for a highly variable proportion of total [As] in fish, often less than 50%. Assuming 20% inorganic arsenic appears to be a poor approximation that cannot be applied to all fish. Based on this considerable variability, we recommend the direct measurement of arsenic species whenever possible, especially when total [As] is elevated above relevant guidelines for the most toxic species (e.g., 0.1-2 mg/kg inorganic arsenic wet wt.). We also recommend future works communicate their results in more detail, including complete description of QAQC protocols, to improve the potential for future meta-analyses. Additional work is needed to characterize arsenic speciation in freshwater fish and assess the toxicity of various arsenic species to accurately evaluate the environmental and human health risks associated with arsenic in fish.

Survey of arsenic content in edible seaweeds and their health risk assessment

Since humans are especially sensitive to arsenic exposure, predominantly through diet, a strict control of the most widely consumed seaweeds is mandatory. Total arsenic contents and arsenic species in twenty-five different seaweeds from five different origins were studied. Seaweeds selected, included Phaeophyta (brown seaweed), Chlorophyta (green seaweed) and Rhodophyta (red seaweed) genera. The highest arsenic content appears in the Phaeophyta seaweed in the range from 11 to 162 mg kg−1 dried weight. Arsenosugars were found to be the predominant species of arsenic in most seaweeds, being up to 99.7% of total arsenic in some samples. The arsenic dietary intakes for seaweeds studied were assessed and the Target Hazard Quotients (THQ) and the Target Cancer Risk (TCR) were calculated, taking into account inorganic arsenic contents (iAs). iAs species in seaweeds showed low risk of arsenic intake except for Hizikia fusiforme samples.

Genotoxicity in humans exposed to arsenic, lithium, and boron in drinking water in the Bolivian Andes-A cross sectional study.

Elevated concentrations of arsenic, lithium and boron in drinking water have already been reported in Bolivia. Arsenic is known to cause genotoxicity but that caused by lithium and boron is less well known. The aim of the present cross-sectional study was to evaluate potential genotoxic effects of exposure to arsenic, while considering exposure to lithium and boron and genetic susceptibility. Women (n = 230) were recruited in villages located around Lake Poopó. Exposure to arsenic was determined as the sum of concentrations of arsenic metabolites inorganic arsenic, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in urine. Exposure to lithium and boron was determined based on their concentrations in urine. Genetic susceptibility was determined by GSTM1 (glutathione S-transferase-mu-1) and GSTT1 (glutathione S-transferase-theta-1) null genotypes and AS3MT (Arsenite Methyltransferase) rs3740393. Genotoxicity was measured in peripheral blood leukocytes using the comet assay. The geometric means of arsenic, lithium, and boron concentrations were 68, 897, and 3972 μg/L, respectively. GSTM1 and GSTT1 null carriers had more DNA strand breaks than gene carriers (p = .008, p = .005). We found no correlation between urinary arsenic and DNA strand breaks (rS = .03, p = .64), and only a weak non-significant positive association in the adjusted multivariate analysis (β = .09 [-.03; .22], p = .14). Surprisingly, increasing concentrations of lithium in urine were negatively correlated with DNA strand breaks (rS = -.24, p = .0006), and the association persisted in multivariate analysis after adjusting for arsenic (β = -.22 [-.36; -.08], p = .003). We found no association between boron and DNA strand breaks. The apparent protective effect of lithium merits further investigation.

Correlation analysis of urinary arsenic species and health effect indicators of occupational arsenic exposure workers

Objective: To explore the correlation between urinary arsenic and health effects through the determination and analysis of urinary arsenic levels in occupational arsenic exposed workers. Methods: In November 2021, 95 workers exposed to arsenic and its inorganic compounds and 31 administrative personnel from a non-ferrous metal smelter in Yunnan Province were selected as the contact group and control group, respectively. Urine forms of arsenic, blood tumor markers, liver function were detected, and micronucleus test was used to analyze the chromosome damage. The correlation between urine forms of arsenic and health effects were analyzed. Results: Compared with the control group, the concentrations of urinary trivalent inorganic arsenic (iAs(3+)) , pentavalent inorganic arsenic (iAs(5+)) , inorganic arsenic (iAs=ΣiAs(3+)+iAs(5+)) , monomethyl arsenic (MMA) , dimethyl arsenic (DMA) and urinary arsenic (ΣiAs+MMA+DMA) at the end of class in contact group were higher (P<0.05) . There was no statistically significant difference in blood tumor markers and liver function indicators between the two groups (P>0.05) . Compared with the control group, the peripheral blood micronucleus rate and cell micronucleus rate in the contact group were significantly increased (P<0.05) . The urinary arsenic, iAs(5+), inorganic arsenic and DMA were positively correlated with peripheral blood micronucleus rate in contact group (r(s)=0.48, 0.34, 0.37, 0.23, P<0.05) , and the urinary arsenic, iAs(5+), DMA were positively correlated with peripheral blood micronucleus rate (r(s)=0.48, 0.34, 0.26, P<0.05) . Conclusion: There is a significant correlation between different valence states of arsenic in the urine and abnormal health effects of occupational arsenic exposed workers. It is necessary to strengthen the detection of arsenic species in the urine of occupational arsenic exposed workers to better protect their health.

Assessment of health risks associated with prediction of vegetable inorganic arsenic concentrations given different soil properties.

Inorganic arsenic (iAs) is a carcinogen. Vegetables such as water spinach (Ipomoea aquatica Forssk.) and amaranth (Amaranthus mangostanus L.) are recognized as high-risk sources of iAs exposure because they can accumulate significant amounts of iAs and are widely consumed. To ensure safe cultivation conditions, this study aimed to establish prediction models for iAs concentration in the edible parts of water spinach and amaranth based on soil properties. Subsequently, health risk assessments associated with iAs exposure through the consumption of these vegetables were conducted using prediction models. Soil samples were collected from agricultural fields in Taiwan and used in the pot experiments. Pearson correlation and partial correlation analyses were used to explore the relationship between soil properties, including total As, clay, organic matter, iron oxides and available phosphates, and iAs concentration in edible parts of water spinach and amaranth. Prediction models based on soil properties were developed by stepwise multiple linear regression. Health risk assessments were conducted using the Monte Carlo algorithm. The results indicate that total As and organic matter contents in soil were major predictors of iAs concentration in water spinach, whereas those in amaranth were total As and clay contents. Therefore, higher health risks for consuming water spinach and amaranth are associated with higher levels of organic matter and clay contents in soil, respectively, and these are crucial factors to consider to ensure food safety. This study suggested that As-elevated soils enriched with organic matter and clay contents should be avoided when growing water spinach and amaranth, respectively.

Biochemical response and tissue-specific accumulation of scallop Aequipecten tehuelchus from Patagonia, Argentina after exposure to inorganic arsenic

This study investigates the effects of different inorganic arsenic (As III) concentrations (0, 125, 500 and 1000 μg As/L) following two exposure times (7 and 14 days) on gills, digestive gland and muscle of scallop Aequipecten tehuelchus from Patagonia, Argentina. A biochemical approach was used to investigate oxidative stress-related parameters after different As concentrations and exposure times. Although the accumulation of As was of the same order of magnitude in all tissues, the results showed distinct tissue-specific oxidative responses to this metalloid. Furthermore, the variation in exposure time had no significant effect on As accumulation in any of the three tissues. In gills, despite no reactive oxygen and nitrogen species (RONS) were detected, there was an increase in catalase (CAT) activity and metallothionein (MT) levels. Conversely, digestive gland showed RONS production without a rise in CAT and glutathione S-transferases (GST) activities, but with an increase in MT levels. In muscle, RONS production and CAT activity kept constant or decreased, while MT levels remained unchanged. In addition, exposure time demonstrated its critical role in gills by influencing the response of CAT, GST and MT, particularly at high As concentrations, while exposure time did not affect the biochemical stress parameters in the digestive gland and muscle. Interestingly, neither concentration of As produced lipid damage, showing the effectiveness of the antioxidant mechanisms to avoid it. These results emphasize that A. tehuelchus exhibited no time-dependent effects in response to As exposure, while showing tissue-specific responses characterized by significant concentration-dependent effects of As. This study provides a comprehensive insight by considering the combined effects of time and concentration of a contaminant and distinguishing its effects on specific tissues, a dimension often overlooked in the existing literature. Subsequent studies should prioritize the analysis of additional contaminants in species with increased sensitivity.

Regulation and mechanism of pyrite and humic acid on the toxicity of arsenate in lettuce

Pyrite and humic acid are common substances in nature, and the combined effects of pyrite and humic acid on arsenic phytotoxicity are more widespread in the actual environments than that of a single substance, but have received less attention. In this study, the interaction between pyrite and humic acid in arsenate solution was studied, and the effects of pyrite and humic acid on plant toxicity of arsenate were evaluated. The results showed that arsenate + pyrite + fulvic acid (V-PF) treatment immobilized more arsenic by forming chemical bonds such as AsS and Fe-As-O and reduced the migration of arsenic to plants. Compared to the arsenate + fulvic acid (VF), arsenate + pyrite (VP) and arsenate (V) group, the inorganic arsenic content of lettuce leaves in the V- PF group was reduced by 19.8 %, 13.4 % and 13.4 %, respectively. In addition, the V-PF group increased the absorption of Ca, Fe and Cu in plant roots, and improved the activity of superoxide dismutase (SOD) in plant leaves. Compared to the VF group, SOD and MDA in the V-PF group increased by 34.1 % in 30 days and decreased by 47.3 % in 40 days, respectively. The biomass of lettuce in V-PF group was increased by 29.3 % compared with that in VF group on day 50. The protein content of the V-PF group was 58.3 % higher than that of the VF group and 23.1 % higher than that of the VP group. Furthermore, metabolomics analysis showed that the V-PF group promoted glycolysis by up-regulating glyoxylic acid and dicarboxylic acid metabolism, thus reducing carbohydrate accumulation. Phosphocreatine metabolism was also up-regulated, which decreased the oxidative damage in lettuce induced by arsenic. This study will provide new ideas for scientifically and rationally assessing the ecological environmental risks of arsenic and regulating its toxicity.

Characteristics of arsenic speciation in mainly cultured shellfish from Sanmen Bay, Zhejiang Province, China

Sanmen Bay plays a crucial role in economic shellfish aquaculture in China, yet few studies exist on the arsenic speciation of shellfish from this area. In this study, arsenic speciation of 11 cultured shellfish species from Sanmen Bay were analyzed by HPLC/ICP-MS. The results showed that organic arsenic particularly AsB, was the dominant arsenic species, constituting 21 %–71 % of the total arsenic. Conversely, the levels of inorganic arsenic were relatively low, ranging from 0.007 to 0.093 mg/kg, only accounted for 0.2 %–5.7 % of the total arsenic. There was no significant level correlation between inorganic arsenic and total arsenic in Sanmen Bay shellfish, so the concentration of inorganic arsenic did not increase with the total arsenic. Overall, the present study firstly revealed the arsenic speciation of shellfish from Sanmen Bay and also suggested that the proportion of inorganic arsenic should be considered in the revision of arsenic limit values.

Association of arsenic exposure with measles antibody titers in US children: Influence of sex and serum folate levels

Exposure to arsenic during childhood is associated with various adverse health conditions. However, little is known about the effect of arsenic exposure on vaccine-related humoral immunity in children. We analyzed data from the National Health and Nutrition Examination Survey (2003–2004 and 2009–2010) to study the relationship between urinary arsenic and measles antibody levels in 476 US children aged 6–11. Multivariable linear regression was used to evaluate the association, adjusting for cycle, age, race, body mass index (BMI), serum cotinine, poverty index ratio, and vitamin B12 and selenium intakes. Stratified analyses were conducted by sex and serum folate levels using the median as cutoff (18.7 ng/mL). The measles antibody concentrations in the 3rd and 4th quartiles were found to have significantly decreased by 28.5 % (95 % Confidence Interval (CI) −47.6, −2.28) and 36.8 % (95 % CI −50.2, −19.5), compared to the lowest quartile among boys with serum folate levels lower than 18.7 ng/ml. The serum measles antibody titers significantly decreased by 16.7 % (95 %CI −25.0, −7.61) for each doubling of creatinine-corrected urinary total inorganic arsenic concentrations in the same group. No associations were found in boys with high serum folate levels or in girls. Further prospective studies are needed to validate these findings and develop interventions to protect children from infectious diseases.

Quantitative benefit and risk assessment of arsenic and nutrient levels in tilapia products sold on Chinese e-commerce platforms.

E-commerce platforms have become a significant sales channel for processed tilapia products such as frozen tilapia fillets, pickled tilapia, and canned tilapia in China. As food safety issues are worldwide concerned, the imbalance between the nutritional benefits of fish and the risk of contamination has become a major constraint on fish consumption. Therefore, it is necessary to assess the safety of tilapia products sold on e-commerce platforms. We conducted a quantitative benefit-risk assessment of arsenic and nutrient levels for tilapia products sold on Chinese e-commerce platforms using the hazard quotient (HQ). A total of 147 tilapia products were collected from the central Chinese e-commerce platforms Tmall, Taobao, and Jingdong for arsenic determination. Arsenic concentrations in tilapia products ranged from 0.004 to 0.820mg·kg-1. The inorganic arsenic content of tilapia products was lower than the national limit (0.1mg·kg-1). One-way analysis of variance revealed that there was no significant difference in arsenic levels in tilapia products among different regions (p > 0.05), while there was a significant difference in product form, with canned tilapia containing significantly higher arsenic levels than frozen tilapia fillets and pickled tilapia fillets (p < 0.05). We conducted an aquaculture experiment to analyze the nutrient levels of tilapia. The mean value of EPA + DHA content of tilapia was 20.634mg·100g-1. The HQ values of tilapia products ranged from 0.004 to 0.736. In a word, the nutritional benefits of consuming tilapia products exceed the risk of arsenic exposure. These data can help demonstrate that tilapia products are low-risk, high-yield nutritious food and provide relevant safety recommendations for consumers purchasing processed tilapia products online.

Enzymatic Hydrolysis of Orange-Footed Sea Cucumber (Cucumaria frondosa)-Effect of Different Enzymes on Protein Yield and Bioactivity.

While sea cucumber is a food delicacy in Asia, these food resources are less exploited in Europe. The aim of this study was to determine the chemical composition and potential food applications of the less exploited orange-footed sea cucumber (Cucumaria frondosa). In particular, the antioxidative capacity and free amino acids associated with the umami flavor released by enzymatic hydrolyses by either Bromelain + Papain (0.36%, 1:1) or Alcalase (0.36%) were studied. Fresh C. frondosa contained approximately 86% water, and low levels of ash (<1%) and lipids (<0.5%). The protein content was 5%, with a high proportion of essential amino acids (43%) and thus comparable to the FAO reference protein. The high concentration of free amino acids associated with umami, sour, sweet, and bitter may contribute to flavor enhancement. Hydrolysis by Bromelain + Papain resulted in the highest protein yield, and the greatest concentration of free amino acids associated with umami and sour taste. All samples showed promising antioxidant capacity measured by FRAP, ABTS, DPPH and ORAC compared to previous reports. The inorganic arsenic concentration of fresh C. frondosa ranged from 2 to 8 mg/kg wet weight and was not affected by processing. This is comparable to other seafood and may exceed regulatory limits of consumption.

Trans-Global Biogeochemistry of Soil to Grain Transport of Arsenic and Cadmium

Previous studies have shown that arsenic and cadmium can accumulate in rice grain to levels that cause health concerns. Furthermore, geographical survey has shown that there is considerable variation (~ 100-fold) in accumulation of these carcinogens in rice grain. This variance must be due to heterogeneity in soil biogeochemistry and contrasting rice management regimens. Here we present the first systematic global study to investigate the impact of soil biogeochemistry on accumulation of these elements in rice grain. Matched grain, shoot, root and soil samples were collected across a latitudinal gradient from East Africa to Europe and soil, shoot, grain chemistry and soil microbial community (prokaryotes and fungi) assessed within the context of arsenic and cadmium biogeochemistry. European and Vietnamese grain sum of arsenic species (inorganic arsenic plus dimethylarsonic acid) concentration medians, ~ 0.1 mg/kg, were found to be around ten-fold higher compared to those in East Africa and Sri Lanka. Arsenic concentrations were linked to higher levels of soil arsenic, and to higher abundance of soil sulphur-oxidising and sulphate reducing bacteria and methanogenic archaea. For cadmium, Sri Lanka showed highest (median 0.0156 mg/kg) and Europe lowest (median of 0.001 mg/kg) levels in grain, with the other regions showing intermediate values. Interestingly, grain cadmium was unrelated to soil cadmium concentrations, with Europe having the highest levels of cadmium in soil. Instead, grain cadmium correlated with higher oxidation/reduction potential, lower -log[hydrogen ion], lower soil calcium, and to a higher abundance of aerobic bacteria and fungi (lowest abundance of these organisms in European soils).

Low-to-Moderate Arsenic Exposure and Urothelial Tract Cancers with a Long Latent Period of Follow-Up in an Arseniasis Area

BackgroundArsenic exposure can cause adverse health effects. The effects of long-term low-to-moderate exposure and methylations remain unclear.ObjectiveThis study aims to examine the association between low-to-moderate arsenic exposure and urothelial tract cancers while considering the effects of methylation capacity.MethodsIn this study, 5,811 participants were recruited from an arseniasis area in Taiwan for inorganic arsenic metabolite analysis. This follow-up study was conducted between August 1995 and December 2017. We identified 85 urothelial tract cancers in these participants, including 49 bladder and 36 upper urothelial tract cancer cases. A Cox proportional hazards model was employed.ResultsThe analyses revealed a significant association between concentrations of inorganic arsenic in water > 100 ug/L and bladder cancer occurrence, with a hazard ratio (HR) of 4.88 (95% CI 1.35–17.61). A monotonic trend was observed between concentrations of inorganic arsenic in water (from 0 to > 100 ug/L) and the incidence of urothelial tract cancer, including bladder cancer (p < 0.05) and upper urothelial tract cancers (p < 0.05). Participants with a lower primary methylation index or higher secondary methylation index had a prominent effect.ConclusionsRigorous regulations and active interventions should be considered for populations with susceptible characteristics.

Carcinogenic and Non-Carcinogenic Health Risks Assessment of Elemental Contaminants in &lt;I&gt;Laminariae thalli&lt;/I&gt;

Scientific relevance. Laminariae thalli are a native herbal preparation used to prevent or treat multiple diseases. To achieve the optimal effect, this herbal preparation is usually taken for several weeks or months. The control of Laminariae thalli should extend beyond the element content in the herbal drug limited by specifications; additionally, it is important to assess the health risks of ingesting heavy metals with the medicinal product during the exposure period.Aim. The study aimed to assess the carcinogenic and non-carcinogenic risks of consuming elemental contaminants with therapeutic doses of herbal medicinal products based on Laminariae thalli.Materials and methods. The study investigated the content of elemental contaminants (Al, As, Cd, Cr, Co, Cu, Fe, Hg, Mn, Mo, Ni, Se, Pb, Sr, V, and Zn) in Laminaria saccharina and Laminaria japonica. The content of inorganic arsenic was determined by solid-phase extraction using inductively coupled plasma mass spectrometry (ICP-MS).Results. When averaged at the 90th percentile level, the mean concentrations of the specified elements did not exceed the limits for seaweed and seagrass foods. The total hazard index from exposure to all analysed elements amounted to 0.173 at the median level and 0.616 at the 90th percentile level. The leading contributors to the total hazard index were As, Fe, Cd, and Sr. The individual carcinogenic risk (CR) values for the potential carcinogens (As, Cd, Pb, and Cr) fell within the range of 1×10-6&lt;CR&lt;1×10-4.Conclusions. If the elements analysed are ingested with a daily therapeutic dose of Laminariae thalli for the exposure period, their total negative effect will not cause harm to the human body. To eliminate the risk of developing neoplasms when the studied medicinal product (Laminariae thalli) is taken at its maximum recommended therapeutic dose for a month or more, the Cr content should be controlled along with the elements limited by specifications for herbal medicines.

Effects of Varied Forms of Arsenic Stress on Seedling Growth and Arsenic Distribution in Honeysuckle Plants

At present, soil arsenic contamination is one of the prominent environmental problems. The arsenic concentration in honeysuckle exceeds the standard levels, thus affecting the quality of traditional Chinese medicine. In this study, the hydroponic method was employed to explore the effect of organic arsenic (dimethyl arsenic) and trivalent inorganic arsenic (NaAsO2) on the growth of honeysuckle plants. The study demonstrated that low concentrations of inorganic arsenic (10–20 mg/L) and 10–50 mg/L organic arsenic had a stimulating effect on the growth of honeysuckle plants. The activities of antioxidant enzymes (peroxidase and catalase) increased correspondingly. However, the antioxidant system in honeysuckle plants was damaged under high concentrations of inorganic arsenic (20–40 mg/L) and 50–70 mg/L organic arsenic. On exposure to 30 mg/L NaAsO2 or 50 mg/L dimethyl arsenic acid for 10 days, the activities of peroxidase and catalase, as well as the malondialdehyde content, increased with prolonged exposure. The micro X-ray fluorescence analysis revealed that the accumulated arsenic in the roots was transported from the central vascular cylinders to the outer part of the root with the increase in concentration and exposure duration of inorganic arsenic. However, organic arsenic stress did not result in significant variations in the distribution of arsenic with increasing concentrations of arsenic. The arsenic element was predominantly located in the middle woody part of the root. The distributions of arsenic in the stems and leaves, in terms of organic and inorganic arsenic stresses, were similar, with accumulation primarily in the cortex of the stem and veins of the leaves. As a commonly used bulk traditional Chinese medicine, honeysuckle has a wide range of product quality issues. Hence, exploring the absorption, distribution, and transport trends of heavy metals such as arsenic in the plant body is of great significance for scientifically evaluating the impact of heavy metal pollution on the quality of medicinal materials and exploring ways to reduce the accumulation of heavy metals in the medicinal parts of plants.