Accumulation of essential and non-essential trace elements in rice grain: Possible health impacts on rice consumers in West Bengal, India

Nano-enabled strategies to promote safe crop production in heavy metal(loid)-contaminated soil

Nanobiotechnology is a potentially safe and sustainable strategy for both agricultural production and soil remediation, yet the potential of nanomaterials (NMs) application to remediate heavy metal(loid)-contaminated soils is still unclear. A meta-analysis with approximately 6000 observations was conducted to quantify the effects of NMs on safe crop production in soils contaminated with heavy metal(loid) (HM), and a machine learning approach was used to identify the major contributing features. Applying NMs can elevate the crop shoot (18.2 %, 15.4-21.2 %) and grain biomass (30.7 %, 26.9-34.9 %), and decrease the shoot and grain HM concentration by 31.8 % (28.9-34.5 %) and 46.8 % (43.7-49.8 %), respectively. Iron-NMs showed a greater potential to inhibit crop HM uptake compared to other types of NMs. Our result further demonstrates that NMs application substantially reduces the potential health risk of HM in crop grains by human health risk assessment. The NMs-induced reduction in HM accumulation was associated with decreasing HM bioavailability, as well as increased soil pH and organic matter. A random forest model demonstrates that soil pH and total HM concentration are the two significant features affecting shoot HM accumulation. This analysis of the literature highlights the significant potential of NMs application in promoting safe agricultural production in HM-contaminated agricultural lands.

Analysis of Heavy Metal Characteristics and Health Risk Assessment of Dried Fish Marketed in Guangzhou, China

This study investigated heavy metal contamination in dried fish sold in Guangzhou, China, and evaluated the resultant non-carcinogenic and carcinogenic health risks. Dried fish samples were purchased from Baiyun, Tianhe, Panyu, and Yuexiu districts in Guangzhou, where the population is substantial. They were randomly acquired in bustling supermarkets and farmers' markets, targeting the most popular dried fish in these areas. Sixty samples from five dried fish types (Stolephorus chinensis, Thamnaconus modestus, Nemipterus-virgatus, river fish, Ctenopharyngodon idella) were analyzed for chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) content. Quantification of the heavy metals were carried out by inductively coupled plasma mass spectrometry (ICP-MS) for Cr, As, Cd, and Pb, and an automatic mercury analyzer for Hg. The median concentration of these heavy metals in dried fish were 0.358 mg/kg, 2.653 mg/kg, 0.032 mg/kg, 0.083 mg/kg, and 0.042 mg/kg, respectively. Pollution severity was ranked as dried Nemipterus-virgatus > dried Stolephorus chinensis > dried Thamnaconus modestus > dried river fish > dried Ctenopharyngodon idella, with As being the most predominant pollutant. All fish types showed severe As pollution. Non-carcinogenic risks were identified in the consumption of dried Nemipterus-virgatus and dried Stolephorus chinensis for both genders, while potential carcinogenic risks were associated with four of the fish types. Women faced higher health risks than men from dried fish consumption. Consequently, we advise consumers to minimize their intake of dried fish and regulatory agencies conduct regular monitoring of heavy metal levels in commercially available dried fish to avert potential health risks.

Environmental and human health risk assessment of soils in areas of ore mineralization and past gold-mining activity

The patterns of the potentially toxic elements (PTEs: Cr, Fe, Ni, Cu, Zn, As, Mo, Pb, Hg) distribution in soils were studied together with the health risk assessment in the area of ore mineralization, past gold activity, and tailing effects of the Sarala gold-ore group located in the Republic of Khakassia, Russia. High PTE concentrations were found in soils with the presence of potential negative impact on human health based on the following: local background investigation, according to statistics; geochemical, environmental, and human health risk calculations; and comparative analysis using international and local reference, such as continental crust, clarke, and permissible concentrations. Sources of PTE soil enrichment and pollution were statistically identified in ascending order of degree: geogenic (local background) < geogenic-technogenic (sites with geological exploration traces - trenches) < technogenic (waste tailings). The main pollutants are Hg and As which showed moderate to significant ecological risk. Negative impact of Cr on soils was found. The pollution degree and toxicity (moderate to significant) of other PTEs increase in the location of ore mineralization zone with exploration trenches and waste tailings. Arsenic poses a carcinogenic risk to adults and children upon contact with polluted soils and non-carcinogenic effect on children in areas affected by tailings and ore mineralization zone. The non-carcinogenic effect of Fe on children was found in soils of all sites. The results provide useful information regarding the studied PTEs and their impact on the environment and human health. Such information can be helpful for the state-level decision-making process when addressing solutions for contaminated areas.

The association between toxic metals (As, Pb and Cd) exposure and rice cooking methods: A systematic review and meta-analysis

Heavy metal exposure through rice consumption (Oryza sativa L.) is a human health concern. This systematic review and meta-analysis investigated the association between toxic metals exposure and rice cooking methods. Based on the inclusion and exclusion criteria, fifteen studies were selected as eligible for the meta-analysis. Our results showed a significant decrease in the content of arsenic, lead, and cadmium following the cooking rice (WMD= -0.04 mg/kg, 95% CI: -0.05, -0.03, P = 0.000), (WMD = -0.01 mg/kg, 95% CI: -0.01, -0.01, P = 0.000), and (WMD = -0.01 mg/kg, 95% CI: -0.01, -0.00, P = 0.000), respectively. Furthermore, based on the subgroup analysis the overall rank order of cooking methods in the rice was rinsed > parboiling > Kateh > high-pressure, microwave, and steaming. The findings of this meta-analysis indicate the beneficial effects of cooking on reducing arsenic, lead, and cadmium exposure via rice consumption.

Dietary sources apportionment and health risk assessment for trace elements among residents of the Tethys-Himalayan tectonic domain in Tibet, China

Dietary intake of toxic elements (TEs) and essential trace elements (ETEs) can significantly impact human health. This study collected 302 samples, including 78 food, 104 drinking water, 73 cultivated topsoil, and 47 sedimentary rock from a typical area of Tethys-Himalaya tectonic domain. These samples were used to calculate the average daily dose of oral intake (ADDoral) and assess the health risks of five TEs and five ETEs. The results indicate that grain and meat are the primary dietary sources of TEs and ETEs for local residents. The intake of manganese (Mn) and copper (Cu) is mainly from local highland barley (66.90% and 60.32%, respectively), iron (Fe) is primarily from local grains (75.51%), and zinc (Zn) is mainly from local yak meat (60.03%). The ADDoral of arsenic (As), Mn, Fe and Zn were found to be higher than the maximum oral reference dose in all townships of study area, indicating non-carcinogenic health risks for local residents. Additionally, lead (Pb) and nickel (Ni) in 36.36% townships, and Cu in 81.82% townships were above the maximum oral reference dose, while As posed a carcinogenic risk throughout the study area. The concentrations of As, mercury (Hg), Pb, Mn, Cu Fe and selenium (Se) in grains were significantly correlated with those in soils. Moreover, the average concentrations of As in Proterozoic, Triassic, Jurassic and Cretaceous was 43.09, 12.41, 15.86 and 6.22 times higher than those in the South Tibet shell, respectively. The high concentrations of TEs and ETEs in the stratum can lead to their enrichment in soils, which, in turn, can result in excessive intake by local residents through the food chain and biogeochemical cycles . To avoid the occurrence of some diseases caused by dietary intake, it is necessary to consume a variety of exotic foods, such as high-selenium foods, foreign rice and flour in order to improve the dietary structure.

Dynamic crosstalk between silicon nanomaterials and potentially toxic trace elements in plant-soil systems

Agricultural soil pollution with potentially toxic trace elements (PTEs) has emerged as a significant environmental concern, jeopardizing food safety and human health. Although, conventional remediation approaches have been used for PTEs-contaminated soils treatment; however, these techniques are toxic, expensive, harmful to human health, and can lead to environmental contamination. Nano-enabled agriculture has gained significant attention as a sustainable approach to improve crop production and food security. Silicon nanomaterials (SiNMs) have emerged as a promising alternative for PTEs-contaminated soils remediation. SiNMs have unique characteristics, such as higher chemical reactivity, higher stability, greater surface area to volume ratio and smaller size that make them effective in removing PTEs from the environment. The review discusses the recent advancements and developments in SiNMs for the sustainable remediation of PTEs in agricultural soils. The article covers various synthesis methods, characterization techniques, and the potential mechanisms of SiNMs to alleviate PTEs toxicity in plant-soil systems. Additionally, we highlight the potential benefits and limitations of SiNMs and discusses future directions for research and development. Overall, the use of SiNMs for PTEs remediation offers a sustainable platform for the protection of agricultural soils and the environment.

Metal(loid) Analysis of Commercial Rice from Malaysia using ICP-MS: Potential Health Risk Evaluation

Rice is a predominant staple food in many countries. It is a great source of energy but can also accumulate toxic and trace metal(loid)s from the environment and pose serious health hazards to consumers if overdosed. This study aims to determine the concentration of toxic metal(loid)s [arsenic (As), cadmium (Cd), nickel (Ni)] and essential metal(loid)s [iron (Fe), selenium (Se), copper (Cu), chromium (Cr), cobalt (Co)] in various types of commercially available rice (basmati, glutinous, brown, local whites, and fragrant rice) in Malaysia, and to assess the potential human health risk. Rice samples were digested following the USEPA 3050B acid digestion method and the concentrations of metal(loid)s were analyzed using an inductively coupled plasma mass spectrometry (ICP-MS). Mean concentrations (mg/kg as dry weight) of metal(loid)s (n=45) across all rice types were found in the order of Fe (41.37)>Cu (6.51)>Cr (1.91)>Ni (0.38)>As (0.35)>Se (0.07)>Cd (0.03)>Co (0.02). Thirty-three percent and none of the rice samples surpassed, respectively, the FAO/WHO recommended limits of As and Cd. This study revealed that rice could be a primary exposure pathway to toxic metal(loid)s, leading to either noncarcinogenic or carcinogenic health problems. The non-carcinogenic health risk was mainly associated with As which contributed 63% to the hazard index followed by Cr (34%), Cd (2%), and Ni (1%). The carcinogenic risk to adults was high (>10-4) for As, Cr, Cd, and Ni. The cancer risk (CR) for each element was 5 to 8 times higher than the upper limit of cancer risk for an environmental carcinogen (<10-4). The findings from this study could provide the metal(loid)s pollution status of various types of rice which are beneficial to relevant authorities in addressing food safety and security-related issues.

A nationwide investigation of trace elements in rice and wheat flour in China: Levels, spatial distributions and implications for human exposure

Rises in trace element contents in rice and wheat flour, which are staple foods for almost all the Chinese population, associated with rapid economic development have raised major concerns. This study aimed to assess trace element concentrations in these foods nationwide in China and associated human exposure risks. For these purposes, nine trace elements were measured in 260 rice samples and 181 wheat flour samples with 17 and 12 widely scattered geographical origins in China, respectively. Mean concentrations (mg kg^-1) of the trace elements declined in the following orders: Zn > Cu > Ni > Pb > As > Cr > Cd > Se > Co in rice, and Zn > Cu > Ni > Se > Pb > Cr > Cd > As > Co in wheat flour. Significant regional differences in levels of trace elements in both rice and wheat flour were detected (p < 0.05), which may be related to local economic indicators. The hazard index (HI) of trace elements in rice samples from all origins exceeded 1, mainly due to the contribution of As, suggesting a potential non-carcinogenic risk. The total carcinogenic risk (TCR) for rice and wheat flour of all origins exceeded the safe level.

Different levels of arsenic exposure through cooked rice and its associated benefit-risk assessment from rural and urban populations of West Bengal, India: a probabilistic approach with sensitivity analysis

Rice arsenic (As) contamination and its consumption poses a significant health threat to humans. The present study focuses on the contribution of arsenic, micronutrients, and associated benefit-risk assessment through cooked rice from rural (exposed and control) and urban (apparently control) populations. The mean decreased percentages of As from uncooked to cooked rice for exposed (Gaighata), apparently control (Kolkata), and control (Pingla) areas are 73.8, 78.5, and 61.3%, respectively. The margin of exposure through cooked rice (MoE_{cooked rice}) < 1 signifies the existence of health risk for all the studied exposed and control age groups. The respective contributions of iAs (inorganic arsenic) in uncooked and cooked rice are nearly 96.6, 94.7, and 100% and 92.2, 90.2, and 94.2% from exposed, apparently control, and control areas. LCR analysis for the exposed, apparently control, and control populations (adult male: 2.1 × 10^-3, 2.8 × 10^-4, 4.7 × 10^-4; adult female: 1.9 × 10^-3, 2.1 × 10^-4, 4.4 × 10^-4; and children: 5.8 × 10^-4, 4.9 × 10^-5, 1.1 × 10^-4) through cooked rice is higher than the recommended value, i.e., 1 × 10^-6, respectively, whereas HQ > 1 has been observed for all age groups from the exposed area and adult male group from the control area. Adults and children from rural area showed that ingestion rate (IR) and concentration are the respective influencing factors towards cooked rice As, whereas IR is solely responsible for all age groups from urban area. A vital suggestion is to reduce the IR of cooked rice for control population to avoid the As-induced health risks. The average intake (μg/day) of micronutrients is in the order of Zn > Se for all the studied populations and Se intake is lower for the exposed population (53.9) compared to the apparently control (140) and control (208) populations. Benefit-risk assessment supported that the Se-rich values in cooked rice are effective in avoiding the toxic effect and potential risk from the associated metal (As).

Micronutrients and heavy metals in rice farms: the case of Ahvaz and Bawie Counties, Khuzestan Province, Iran

This study addressed micronutrients (Fe, Zn, Cu, Mn, Co) and heavy metals (As, Pb) in the soil and rice crop in Khuzestan Province, Iran. Twenty-eight composite soil and grain samples from the intended rice farms were garnered during harvest time. Concentrations of the elements in the samples and in the grains were, respectively, determined by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry device. The average concentration of As, Fe, Co, Cu, Mn, Pb, and Zn in soil of crop were 2.71, 20,065.8, 10.43, 22.28, 422.28, 5.85, and 47.07 mg/kg, respectively. The physicochemical properties of soil, bioconcentration factor, daily intakes, and health risk assessment of the elements were calculated. The results revealed that the area covered by alkaline saline soils is poor in micronutrients. Bioconcentration factor values of all elements were less than 1. Low levels of bioconcentration factor may be for low levels of nutrients in the soil and physicochemical conditions of the soil. Furthermore, the daily intake of Co (adults' group) and Fe and Zn (children group) was very low. Health risk assessment showed only adults are threatened by non-cancerous diseases due to excessive value of all the elements (HI = 2.53) and cancerous diseases caused by excessive As and Pb (2.86E-04 and 2.01E-05, respectively). Considering that Khuzestan Province is the fourth largest producer of rice in Iran, the lack of micronutrients and the presence of heavy metals in rice produced in the study area can adversely affect consumers. Further investigation is therefore a must in the region.

Quercetin Abates Aluminum Trioxide Nanoparticles and Lead Acetate Induced Altered Sperm Quality, Testicular Oxidative Damage, and Sexual Hormones Disruption in Male Rats

This study examined the effects of exposure to lead acetate (PbAc) and/or aluminum trioxide nanoparticles (Al₂O₃NPs) on testicular function. Additionally, the probable reproprotective effects of quercetin (QTN) against Al₂O₃NPs and PbAc co-exposure in male Sprague Dawely rats were assessed. Al₂O₃NPs (100 mg/kg b.wt.), PbAc (50 mg/kg b.wt.), and QTN (20 mg/kg b.wt.) were orally administered for 60 days. Then, spermiogram, histopathological examinations of the testis and accessory glands, and immunohistochemical detection of androgen receptors (AR) and tumor necrotic factor alpha (TNF-α) were achieved. Moreover, serum levels of male sex hormones and testicular levels of antioxidant indices were estimated. The results showed that Al₂O₃NP_s and/or PbAc caused significant sperm abnormalities, testicular oxidative stress, and histopathological changes. Furthermore, serum testosterone, LH, and FSH levels significantly decreased, while estradiol levels significantly increased. The Al₂O₃NPs and/or PbAc co-exposed group had more obvious disturbances. Furthermore, QTN co-administration significantly reversed the Al₂O₃NPs and PbAc-induced testicular histopathological alterations, reduced antioxidant defenses, and altered AR and TNF-α immune expression in testicular tissues. Conclusively, Al₂O₃NPs and/or PbAc evoked testicular dysfunction by inducing oxidative injury and inflammation. However, QTN oral dosing effectively mitigated the negative effects of Al₂O₃NPs and PbAc by suppressing oxidative stress and inflammation and improving the antioxidant defense system.

Could Consumption of Trace Element-Contaminated Rice Be a Risk Factor for Acute Interstitial Nephritis with Uncertain Etiology in the Dry Zone of Sri Lanka?

Ingestion of toxic trace elements in the human body has been considered one of the major reasons for renal dysfunction. Chronic kidney disease with uncertain etiological factors (CKDu) is a recently described clinical entity in which the disease is found in geographically isolated pockets in the dry zone of Sri Lanka. In CKDu regions, an increasing number of cases are reported with acute interstitial nephritis without any known reason (AINu). However, recent exposure to certain risk behaviors or nephrotoxins, or both, is suspected for the AINu. Consumption of foods that are contaminated with trace elements is one of the main pathways of human exposure to environmental toxins. The current study was carried out to assess the possibility of trace element-contaminated rice consumption on the etiopathogenesis of AINu. Samples of rice consumed by 32 clinically diagnosed AINu cases were collected and analyzed for possible nephrotoxic trace elements. Out of 32 patients, 26 were histologically confirmed with tubulointerstitial disease. The results revealed that the mean values of Cd, As, and Pb were 0.18, 0.055, and 0.135 mg/kg, with ranges of 0.020-1.06, 0.012-0.222, and 0.003-0.744 mg/kg (on dry weight basis), respectively. This study indicated that the investigated toxic trace element levels of rice consumed by AINu were reasonably below the recommended levels of the Codex Alimentarius Commission of FAO and WHO. Hence, it is less likely that rice consumption is to be a risk factor for the etiology of AINu.

Concentrations of essential and toxic elements and health risk assessment in brown rice from Qatari market

Twenty-two brown rice varieties available in the Qatari market were analyzed for essential and toxic elements by ICP-MS. Found concentrations (µg/kg) were: As: 171 ± 78 (62-343), Cd: 42 ± 60 (4-253), Cr: 515 ± 69 (401-639), Pb: 6 ± 7 (<MDL-26), and U: 0.1 ± 0.5 (<MDL-2). One third of the samples contained high levels of arsenic. Significant differences (p < 0.008) in concentrations were observed for many elements based on both the grains' country of origin and size. Calculated carcinogenic risk according to published speciation data of inorganic arsenic and chromium(VI) available in the literature for rice is > 1 in million, may possibly be > 1 in 10,000 based on conservatively high brown rice consumption rates of 200 g/d or 400 g/d in Qatar. These elevated risks may be applicable to specific population subgroups with diabetic conditions who consume only brown rice. Non-cancer risks are mainly derived from Mn, V, Se, and Cd with a hazard index > 1 from some brown rice samples.

Pollution monitoring, risk assessment and target remediation of heavy metals in rice from a five-year investigation in Western Fujian region, China

Recently, rice contamination by heavy metals (HMs) has become a severe problem. Taking the Western Fujian region as an example in this study, a total of 1311 rice samples containing eight HMs were collected from 2015 to 2019, then used to explore their pollution characteristics, health risks, and Spatio-temporal variations, finally derive the target remediation areas of the key pollutants. The results showed that average concentrations of all the HMs had not reached the limits of the National Standards of Food Safety, but pollution indexes of As (0.783) and Cu (0.665) were at accumulation level (>0.6), which posed high pollution risks. Furthermore, locations of higher HMs concentrations coincided with those of higher pollution estimation probabilities. The non-carcinogenic risk (4.150, 2.434) and carcinogenic risk (4.96 × 10^-3, 2.92 × 10^-3) for children and adults cannot be negligible, As and Cd were the largest contributors. Children were more susceptible than adults due to the metal concentrations and rice intake rate. The spatio-temporal changes indicated that a decreasing trend in average concentrations of HMs (except Cr), but As (0.37%-0.88%) contents increased in the west and northeast parts, and so did Cd (1.92%-5.11%) in the central region during monitoring. For the target remediation, particular regions in the western and eastern were used as risky areas of As and Cd, respectively. Our results will provide theoretical support for the pollution management of HMs in rice.

Black soybean (Glycine max (L.) Merr.): paving the way toward new nutraceutical

Black soybean (BS) is a nutritious legume that is high in proteins, essential amino acids, dietary fiber, vitamins, minerals, anthocyanins, phenolic acids, isoflavones, and flavones. Traditional approaches for extracting BS bioactive compounds are commonly employed because they are simple and inexpensive, but they use toxic solvents and have lower yields. As a result, new extraction techniques have been developed, such as microwave, ultrasound, and enzyme-assisted extraction. Modern approaches are less harmful to the environment, are faster, and produce higher yields. The major anthocyanin in the BS seed coat was discovered as cyanidin-3-O-glucoside, accounting for nearly 75% of the total anthocyanins. BS and its seed coat also contains phenolic acids (p-hydroxybenzoic, gallic, vanillin, syringic acid), isoflavones (daidzein, glycitein and genistein), flavones, flavonols, flavanones, and flavanols. Bioactive compounds present in BS exhibit antioxidant, anti-cancerous, anti-diabetic, anti-obesity, anti-inflammatory, cardio and neuroprotective activities. The characterization and biological activity investigation of these bioactive compounds has provided researchers and food manufacturers with valuable information for developing functional food products and nutraceutical ingredients. In this review, the nutritional makeup of BS is reviewed, and the paper seeks to provide an insight of bioactive compound extraction methods as well as bioactive compounds identified by various researchers. The biological activities of BS extracts and their potential applications in food products (noodles), biodegradable films (pH sensitive film), and therapeutic applications (wound healing and anti-inflammation) are also discussed in the study. Therefore, BS have enormous potential for use in developing functional foods and nutraceutical components. This is the first review of its sort to describe and explain various extraction methodologies and characterization of bioactives, as well as their biological activity recorded in diverse works of literature, making it possible for food manufacturers and scientists to get a quick overview.

Mapping Paddy Rice Distribution and Cropping Intensity in China from 2014 to 2019 with Landsat Images, Effective Flood Signals, and Google Earth Engine

Paddy rice cropping systems play a vital role in food security, water use, gas emission estimates, and grain yield prediction. Due to alterations in the labor structure and the high cost of paddy rice planting, the paddy rice cropping systems (single or double paddy rice) have drastically changed in China in recent years; many double-cropping paddy rice fields have been converted to single-cropping paddy rice or other crops, especially in southern China. Few maps detect single and double paddy rice and cropping intensity for paddy rice (CIPR) in China with a 30 m resolution. The Landsat-based and effective flooding signal-based phenology (EFSP) method, which distinguishes CIPR with the frequency of the effective flooding signal (EFe), was proposed and tested in China. The cloud/ice/shadow was excluded by bit arithmetic, generating a good observation map, and several non-paddy rice masks were established to improve the classification accuracy. Threshold values for single and double paddy rice were calculated through the mapped data and agricultural census data. Image processing (more than 684,000 scenes) and algorithm implementation were accomplished by a cloud computing approach with the Google Earth Engine (GEE) platform. The resultant maps of paddy rice from 2014 to 2019 were evaluated with data from statistical yearbooks and high-resolution images, with producer (user) accuracy and kappa coefficients ranging from 0.92 to 0.96 (0.76–0.87) and 0.67–0.80, respectively. Additionally, the determination coefficients for mapped and statistical data were higher than 0.88 from 2014 to 2019. Maps derived from EFSP illustrate that the single and double paddy rice systems are mainly concentrated in the Cfa (warm, fully humid, and hot summer, 49% vs. 56%) climate zone in China and show a slightly decreasing trend. The trend of double paddy rice is more pronounced than that of single paddy rice due to the high cost and shortages of rural household labor. However, single paddy rice fields expanded in Dwa (cold, dry winter, and hot summer, 11%) and Dwb (cold, dry winter, and warm summer, 9%) climate zones. The regional cropping intensity for paddy rice coincides with the paddy rice planting area but shows a significant decrease in south China, especially in Hunan Province, from 2014 to 2019. The results demonstrate that EFSP can effectively support the mapping of single and double paddy rice fields and CIPR in China, and the combinations of Landsat 7 and 8 provide enough good observations for EFSP to monitor paddy rice agriculture.

Genome-Wide Characterization of Sedum plumbizincicola HMA Gene Family Provides Functional Implications in Cadmium Response

Heavy-metal ATPase (HMA), an ancient family of transition metal pumps, plays important roles in the transmembrane transport of transition metals such as Cu, Zn, Cd, and Co. Although characterization of HMAs has been conducted in several plants, scarcely knowledge was revealed in Sedum plumbizincicola, a type of cadmium (Cd) hyperaccumulator found in Zhejiang, China. In this study, we first carried out research on genome-wide analysis of the HMA gene family in S. plumbizincicola and finally identified 8 SpHMA genes and divided them into two subfamilies according to sequence alignment and phylogenetic analysis. In addition, a structural analysis showed that SpHMAs were relatively conserved during evolution. All of the SpHMAs contained the HMA domain and the highly conserved motifs, such as DKTGT, GDGxNDxP, PxxK S/TGE, HP, and CPx/SPC. A promoter analysis showed that the majority of the SpHMA genes had cis-acting elements related to the abiotic stress response. The expression profiles showed that most SpHMAs exhibited tissue expression specificity and their expression can be regulated by different heavy metal stress. The members of Zn/Co/Cd/Pb subgroup (SpHMA1-3) were verified to be upregulated in various tissues when exposed to CdCl₂. Here we also found that the expression of SpHMA7, which belonged to the Cu/Ag subgroup, had an upregulated trend in Cd stress. Overexpression of SpHMA7 in transgenic yeast indicated an improved sensitivity to Cd. These results provide insights into the evolutionary processes and potential functions of the HMA gene family in S. plumbizincicola, laying a theoretical basis for further studies on figuring out their roles in regulating plant responses to biotic/abiotic stresses.

Heavy Metal in Rice and Vegetable and Human Exposure near a Large Pb/Zn Smelter in Central China

Non-ferrous metal smelting is a significant source of anthropogenic heavy metal emission and has led to severe environmental pollution that ultimately threatens the health of local residents. In this study, we determined concentrations of copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb), as well as Pb isotopic compositions in rice, vegetables and human hair in areas surrounding the Zhuzhou Pb/Zn smelter in Hunan, China and we assessed the health risks associated with rice and vegetable consumption for local residents. Results showed that rice and vegetable samples were significantly contaminated by Cd and Pb. Age and source of rice were important factors for the enrichment of heavy metal concentrations in human hair. The ratios of Pb isotopes in human hair (1.164-1.170 for ²⁰⁶Pb/²⁰⁷Pb and 2.102-2.110 for²⁰⁸Pb/²⁰⁶Pb) were comparable to those in rice (1.162-1.172 for ²⁰⁶Pb/²⁰⁷Pb and 2.098-2.114 for²⁰⁸Pb/²⁰⁶Pb) and were slightly lower than those in vegetables (1.168-1.172 for ²⁰⁶Pb/²⁰⁷Pb and 2.109-2.111 for²⁰⁸Pb/²⁰⁶Pb), indicating that Pb in human hair mainly originated from food ingestion. A non-carcinogenic risk assessment showed that Cd exposure was the dominant health risk for local residents. This study suggested that crops planted surrounding the smelter were seriously contaminated with Cd and human exposure was related to dietary intake.

Translocation of Soil Arsenic towards Accumulation in Rice: Magnitude of Water Management to Minimize Health Risk

Globally, the risk of arsenic (As) contamination in soil and rice is well documented across the globe. In Bangladesh, drinking water and rice are two major exposure pathways of As to humans. Therefore, the efficiency of recent technologies to reduce rice As and associated human health risks still need to be deeply investigated. In this direction, a pot experiment was performed to investigate the impact of soil As and agronomic irrigation management on rice (cv. BRRI dhan28) growth, yield, As accumulation, and finally, health risks to humans from consuming rice. Treatment combinations were made with three levels of As (0, 20, and 40 mg kg−1) having two irrigation procedures, including alternate wetting and drying (AWD) and traditional continuous flooding (CF). According to the findings, As pollution in the soil lowered the yield contributing features and rice yield, including panicle length, filled grains per panicle, sterile grains per panicle, 1000-grain weight, grain yield, and straw yield. AWD water management significantly improved the growth performance and productivity of rice. Grain yield was increased by 13% in AWD compared to CF. Rice grain and straw As concentrations were increased to 0.56 mg kg−1 and 15.10 mg kg−1, respectively, in soil with 40 mg kg−1 As and CF water management. AWD treatment significantly reduced grain and straw As contents by 16% and 28%, respectively. Increased grain, straw, and total As uptake was noticed with higher soil As concentrations. The study also found that rising soil As raised non-carcinogenic risks (HQ > 1) and carcinogenic risks (CR > 1.010–4) while AWD lowered health risks compared to CF. Thus, rice farming using AWD irrigation could be a viable and long-term solution for reducing As contamination in rice and associated human health hazards.

Steel mill waste application in soil: dynamics of potentially toxic elements in rice and health risk perspectives

Potentially toxic elements (PTEs) are of great concern in steel mill wastes. Therefore, in order to use them as potential fertilizers in soil, risk assessments are needed. Three steel mill wastes were tested as possible amendments for soils at seven different doses (0, 0.5, 1, 2, 4, 8, 16 t ha^-1): phosphate mud (PM), metallurgical press residue (MPR), and filter press mud (FPM) during rice cultivation in a pot experiment in a Haplic Gleisol. Analysis on rice tissues, including roots, shoots, husk, and grains, were conducted and contents of Cu, Cd, Ni, Zn, Mn, and Pb were assessed. Translocation and bioaccumulation factors were calculated for each element. In general, PTEs are more accumulated in roots and greater contents of Zn and Mn were found, while the lowest ones were found for Pb, probably due to its lack of functional roles during plants development. Higher translocation was observed for Mn, which is associated to the redox conditions of rice cultivation and the high mobility of this element under this condition. Application of steel mill wastes can increase PTE bioavailability and translocation factors, especially PM, but all of the wastes reveal a high hazard index.

Indigenous plant protection practices of Tripura, India

BACKGROUND

Traditional plant protection strategies have an integral part of food production system in North Eastern state Tripura, India, which has bestowed with rich heritage and biodiversity. However, there is no comprehensive report on the indigenous plant protection practices (IPPPs) specific to insect and vertebrate pest management, being followed by the inhabitants of the region for centuries. The present study was conducted to investigate, collect, and document the vulnerable IPPP practices followed by the native people from far flung locations of the Tripura.

METHODS

The study aimed to document the IPPP following semi-structured questionnaires, participatory interaction, and direct observations with a total of 200 informants. We have calculated the relative frequencies of citation (RFC) for IPPP and estimated principal component analysis to link the status of IPPP with socio-demographic factors of the informants. The relationship between the field of IPPP used and different covariates (age, education, occupation, gender, location, and house type) was assessed using the Kruskal-Wallis test and Chi-square test. The relationship between adoption level and the respondents' characteristics was analyzed using count regression analysis.

RESULTS

The study found that the status of the IPPP has increased for mitigating pest issues. A total of 39 indigenous practices were recorded specifically to pest management from the ethnic people of Tripura, India. People acquired pretty knowledge about IPPP, and these were inherited from ancestors. The respondents in the study developed notable innovations for the management of many pest issues using locally available resources that warrant cost-effective and eco-friendly. Seed drying before storage to protect grain commodities was the most cited IPPP with a frequency of citation 0.675. In the field of IPPP used, the people primarily practiced agriculture + horticulture + storage category. An important implication from the study is the identification of two IPPP strategies in this region for the first time. Furthermore, the recorded IPPP used field was significantly associated with age, education, occupation, gender, locality, and house type. Likewise, the respondents' socio-demographic variables were coupled considerably with the adoption of specific IPPP.

CONCLUSION

The reported IPPP for alleviating pest problems reflects the wisdom and generosity of the ethnic growers of Tripura, India. The study suggests the IPPP has strong potential in an integrated pest management approach passed down from generation to generation. The vulnerable practices largely remained unexplored due to inadequate scientific scrutiny and authenticity, yet in danger of being lost if not documented systematically. This study provides the first step toward accessing the valuable technology of untapped Tripura in IPPP and could be viable in paving action paradigm for their preservation, diffusion, and application with advanced pest management options.

Remediation of Soil in a Deserted Arsenic Plant Site Using Synthesised MgAlFe-LDHs

Layered double hydroxides (LDHs) are promising soil contamination amendment agents for its efficient absorbing abilities. However, the application of LDHs in remediation of heavy metal contaminated soil are to be developed. In this study, we synthesized MgAlFe-LDHs by introducing Fe³⁺ into interlayer of the MgAl-LDHs using co-precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR) and scanning electron microscope (SEM) were employed to characterized the micro structure of MgAlFe-LDHs. And then pot incubation and pilot experiments were conducted to investigate the heavy metal removal efficiencies of MgAlFe-LDHs and its potential being applicated in As contaminated soil amendment from a deserted arsenic plant site. Incubation experiments showed that the MgAlFe-LDHs had a higher removal efficiency on arsenic contaminated soil compared to other agents. And the results of pilot experiments indicated that the MgAlFe-LDHs can immobilize up to 90% of the As in soil with 5% (w/w) addition. Based on the results above, MgAlFe-LDHs are promising materials amending the heavy metal contaminated soil with practical application value.

Identifying the Food Sources of Selected Minerals for the Adult European Population among Rice and Rice Products

The problem of dietary deficiency of several essential elements among different stages of life is still observed. The consumption of whole grains (among others unprocessed rice) is recommended as a part of a healthy diet. This research aimed to determine the content of selected macro- and microelements in rice and rice products to verify whether the tested products could be regarded as a source of selected minerals in the diet of the adult European population.

METHODS

A total of 99 samples from 12 groups of rice products (basmati, black, brown, parboiled, red, wild, white rice and expanded rice, rice flakes, flour, pasta, and waffles) were obtained. The atomic absorption spectrometry method (AAS) was used to determine the content of Ca, Cu, Fe, Mg, Mn, Se and Zn in the study material.

RESULTS

The average measured contents of Ca, Cu, Fe, Mg, Mn, Se and Zn were as follows: 226.3 ± 160.6 mg/kg, 3.6 ± 2.8 mg/kg, 9.4 ± 7.0 mg/kg, 618.0 ± 498.4 mg/kg, 16.7 ± 10.0 mg/kg, 242.9 ± 140.4 µg/kg and 19.5 ± 15.0 mg/kg, respectively. Statistical analyses confirmed the differences in the levels of the studied elements between the subgroups of processed and unprocessed products. Considering the tolerable upper intake level of studied elements, the tested products could be regarded as safe to consume.

CONCLUSION

All tested products can be recommended as a source of Cu, Mn, and Se, while a majority of studied products can be considered a source of Mg and Zn in the diet of the adult European population.

Risk assessment and hotspots identification of heavy metals in rice: A case study in Longyan of Fujian province, China

The potential threats of heavy metals in rice have attracted increasing attention worldwide. In this study, we assessed the pollution status and health risk of rice collected from Longyan in Fujian, China. Meanwhile, we explored the spatial pattern and hotspots of those metals. The results showed that the average concentrations of Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn in rice were 0.064, 0.002, 0.464, 0.072, 0.138, 0.106, 10.819, and 23.788 mg kg^-1, respectively. Among them, As and Cu remarkably accumulated with the exceeding ratio of 50.30% and 55.12%, respectively. Furthermore, the values of the target hazard quotient in rice ranked as As > Cu > Zn > Cd > Pd > Ni > Hg > Cr, which As and Cu was greater than 1.0. And the carcinogenic risk values were in the order of As > Cd > Ni > Cr, which all exceeded the tolerance level (1 × 10^-4). Risk assessment indicated that both children and adults were posed the non-carcinogenic and carcinogenic risk from rice intake, and As had the largest contribution rate for them. Comparison found that the spatial patterns of heavy metals distribution were consistent with the hotspots. The hotspots for As and Zn located in the western part (Changting and Wuping), Cd and Cu in the eastern part (Xinluo and Yongding), Cr and Ni were simultaneously found in the northeast (Zhangping), while Hg and Pb were mainly located in the central region (Shanghang). Overall, combining the pollution status, risk assessment, and hotspot distribution in rice, the western region (Changting and Wuping) were identified as priority areas for remediation.

Genome-wide association mapping for grain manganese in rice (Oryza sativa L.) using a multi-experiment approach

Manganese (Mn) is an essential trace element for plants and commonly contributes to human health; however, the understanding of the genes controlling natural variation in Mn in crop plants is limited. Here, the integration of two of genome-wide association study approaches was used to increase the identification of valuable quantitative trait loci (QTL) and candidate genes responsible for the concentration of grain Mn across 389 diverse rice cultivars grown in Arkansas and Texas, USA, in multiple years. Single-trait analysis was initially performed using three different SNP datasets. As a result, significant loci could be detected using the high-density SNP dataset. Based on the 5.2 M SNP dataset, major QTLs were located on chromosomes 3 and 7 for Mn containing six candidate genes. In addition, the phenotypic data of grain Mn concentration were combined from three flooded-field experiments from the two sites and 3 years using multi-experiment analysis based on the 5.2 M SNP dataset. Two previous QTLs on chromosome 3 were identified across experiments, whereas new Mn QTLs were identified that were not found in individual experiments, on chromosomes 3, 4, 9 and 11. OsMTP8.1 was identified in both approaches and is a good candidate gene that could be controlling grain Mn concentration. This work demonstrates the utilisation of multi-experiment analysis to identify constitutive QTLs and candidate genes associated with the grain Mn concentration. Hence, the approach should be advantageous to facilitate genomic breeding programmes in rice and other crops considering QTLs and genes associated with complex traits in natural populations.

Effect of the irrigation method and genotype on the bioaccumulation of toxic and trace elements in rice

The total concentration of three toxic elements (As, Cd and Pb) and five oligoelements (Cu, Mn, Mo, Ni and Se) has been determined using an original and completely validated ICP-MS method. This was applied to rice grains from 26 different genotypes cultivated in the same soil and irrigated with the same water in three different ways: by the traditional continuous flooding (CF) and by two intermittent methods, the sprinkler irrigation (SP) and the periodical saturation of the soil (SA). The adoption of SP hugely minimizes the average amounts of almost all elements in kernels (-98% for As, -90% for Se and Mn, -60% for Mo, -50% for Cd and Pb), with the only exception of Ni, whose concentration increases the average amount found in the CF rice by 7.5 times. Also SA irrigation is able to reduce the amounts of As, Mo and Pb in kernels but it significantly increases the amounts of Mn, Ni and - mainly - Cd. Also the nature of the genotype determined a wide variability of data within each irrigation method. Genotypes belonging to Indica subspecies are the best bioaccumulators of elements in both CF and SP methods and, never, the worst bioaccumulators for any element/irrigation method combination. In the principal component analysis, PC1 can differentiate samples irrigated by SP by those irrigated by CF and SA, whereas PC2 provides differentiation of CF samples by SA samples. When looking at the loading plot Ni is negatively correlated to the majority of the other elements, except Cu and Cd having negative loadings on PC2. These results allow to envisage that a proper combination of the irrigation method and the nature of rice genotype might be a very valuable tool in order to successfully achieve specific objectives of food safety or the attainment of functional properties.

Assessment of Rice Marketed in Iran with Emphasis on Toxic and Essential Elements; Effect of Different Cooking Methods

Rice is one of the most valuable nutrients in the diet of most people in the world. The aim of this study was to evaluate the effect of various pre-cooking (washing, soaking) and cooking processes (traditional and rinse) of rice on the amount of toxic and essential elements in the various brands of rice in Iran and assessing human health risks from their carcinogenic and non-carcinogenic effects. For this purpose, totally, 144 sample sizes were examined from three brand (Iranian (n = 48), Pakistani (n = 48), and Indian (n = 48)) in order to the amount of toxic and essential elements using inductively coupled plasma-optical emission spectrometry. The results showed that pre-cooking processes such as washing and soaking in the rinse method were significantly effective in removal toxic metals than the traditional method, so that the most changes were observed for potassium and aluminum metals. The estimated daily intakes of copper, magnesium, manganese, iron, and zinc in different cooking methods were 1.19-1.2%, 0.29-0.32%, 1.01-1.23%, 0.4-0.98%, and 0.9-1.32%, respectively. The Monte Carlo simulation results showed that the rank order of toxic metals of cooked rice based on target hazard quotients value was arsenic > chromium > cadmium > mercury > lead > aluminum, respectively. The result of cancer risk probability was lower than the safe risk limits (1E-4), representing no remarkable cancer risk probability that was due to ingestion of rice for adults and children in Iran. According to the this results, it is recommended to use the rinse method due to further reduction of metals especially toxic metals for rice samples, although the amount of essential elements was also removed by this method.

Heavy Metal Transporters-Associated Proteins in S. tuberosum: Genome-Wide Identification, Comprehensive Gene Feature, Evolution and Expression Analysis

Plants have evolved a number of defense and adaptation responses to protect themselves against challenging environmental stresses. Genes containing a heavy metal associated (HMA) domain are required for the spatiotemporal transportation of metal ions that bind with various enzymes and co-factors within the cell. To uncover the underlying mechanisms mediated by StHMA genes, we identified 36 gene members in the StHMA family and divided them into six subfamilies by phylogenetic analysis. The StHMAs had high collinearity and were segmentally duplicated. Structurally, most StHMAs had one HMA domain, StHIPPc and StRNA1 subfamilies had two, and 13 StHMAs may be genetically variable. The StHMA gene structures and motifs varied considerably among the various classifications, this suggests the StHMA family is diverse in genetic functions. The promoter analysis showed that the StHMAs had six main cis-acting elements with abiotic stress. An expression pattern analysis revealed that the StHMAs were expressed tissue specifically, and a variety of abiotic stresses may induce the expression of StHMA family genes. The HMA transporter family may be regulated and expressed by a series of complex signal networks under abiotic stress. The results of this study may help to establish a theoretical foundation for further research investigating the functions of HMA genes in Solanum tuberosum to elucidate their regulatory role in the mechanism governing the response of plants to abiotic stress.

The role of rice (Oryza sativa L.) in sequestering phosphorus compounds and trace elements: Speciation and dynamics

In southern Florida, the sequestering of nutrients through the cultivation of rice (Oryza sativa L.) in alternation with sugarcane (Saccharum spp.) crops is an essential step in minimizing downstream eutrophication of the Florida Everglades. Phosphorus (P) is known to be the leading cause of this eutrophication; however, the cultivation/harvesting of rice effectively reduces P and additional macro and micro-nutrients from agrarian soil and runoff through plant uptake. In this study, soil, water, sugarcane, and rice plants at two different stages (flooded and vegetative) were analyzed for twelve different elements (Al, As, Co, Cr, Cu, Fe, Ni, Zn, Ca, Mn, Mg, and P) by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). ³¹P Nuclear Magnetic Resonance (NMR) spectra of the rice plants confirmed ten different P compounds being transported and/or transformed throughout the entirety of the sugarcane and rice plants. On average, dried rice plants contained 1677 ± 14 mg-P, of which 1277 ± 3.0 mg-P was in the panicle at the vegetative stage. Harvesting of the rice panicle has the potential to remove about 14.7 kg-P/ha for the top 10 cm of the soil. This present study demonstrates that in rotations with sugarcane crops and with no added P fertilizer, rice cultivation can reduce considerable amounts of P that would otherwise leach into the Greater Everglades from the Everglades Agricultural Area.