Safety Assessment of Herbal Food Supplements: Elemental Profiling and Associated Risk.

Increased usage of herbal food supplements by both the paediatric and adult populations prompted a health risk assessment study. The elemental profiles of 52 supplements collected in Serbia were obtained using ICP-MS. The calculated contribution to permitted daily exposure was in compliance with the guidelines for elemental impurities: up to 46.8% for Pb (infants), 67.2% for Cu (toddlers), 6.8% for As (preschool children), and 8.0% for Hg (adolescents). Hazard quotients indicated high exposure of toddlers to Cu (100.9%) and Zn (112.7%), although by only one supplement, for which hazard indices ranged from 229 to 105% (aligning from toddlers to adolescents). Based on the margin of exposure, As and Pb were not of safety concern. Conversely, the proportion of supplements exceeding the acceptable level of lifetime cancer risk due to As exposure varied from 41.9% in adolescents to 54.3% in adults. Simultaneous use of multiple supplements over a prolonged period of time could further deepen health concerns.

Analysis of non-carcinogenic health risk assessment of elemental impurities in vitamin C supplements.

Objectives: Elemental impurity exposure that may occur in the use of supplements has the potential to pose a risk to human health. Vitamin C supplements are among the most commonly used supplements on a daily basis and in the long-term due to the pharmacological properties of vitamin C. In this study, we aimed to evaluate the non-carcinogenic health risk of elemental impurities that may cause contamination in orally administered vitamin C supplements. Materials and Methods: Ten elemental impurities (Cd, Pb, As, Hg, Co, V, Ni, Cr, Sb, and Sn) in 12 supplements were analyzed using ICP-MS. The estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI) values of elemental impurities were calculated for non-carcinogenic risk assessment. Cancer risk (CR) was additionally calculated for elemental impurities with carcinogenic properties detected in the samples. Results: Low levels of Cr and Hg were detected in some samples. While the HQ values of sample 1, sample 2, sample 8, and sample 9 for Hg were calculated as 0.054, 0.096, 0.064, and 0.086, respectively, the HQ values of sample 5, sample 10, and sample 11 for Cr were calculated as 0.011, 0.017, and 0.014, respectively. Since only Hg or only Cr was detected in samples with elemental impurity, the HI values in the samples are the same as the HQ values. Since the HQ and HI values calculated from the samples are not≥1, there is no elemental impurity at a level that will hazard human health through supplement use. Other carcinogenic elements were not detected in the samples except Cr. In sample 5, sample 10, and sample 11, the CR values for Cr were 1.767.10-5, 2.571.10-5, and 2.089.10-5, respectively. In probability simulation, while HQ and CR values of Cr did not exceed the allowable value, the HQ level for Hg in the 95% slice was higher than the allowable value. Conclusion: There is no risk to human health and there is no critical difference between the supplements considering the elemental pollutant content among the vitamin C supplements of different trademarks. However, in order to keep the Hg level, which has a potential risk capacity, at low limits, it is recommended that the necessary risk-reducing measures be taken by the authorities and further studies be carried out.

Chemometric and risk assessment of nitrogen composition of atmospheric rainwater from diverse surfaces in Rivers State, Nigeria.

Organic and inorganic nitrogen ions in the environment play important role across environmental matrices. Rainwater samples collected from ambient and different roofing surfaces (zinc, aluminium, asbestos and stone-coated roofing sheets) from selected locations at Ogale, Rumuodomaya/Rumuodome, Diobu and Chokocho within Rivers State, Niger Delta, Nigeria, from April to June, July to August and September to October depicting three regiments of early, mid and late rains. The samples were analysed for Kjeldahl nitrogen, ammonium, nitrate and nitrite using APHA methodology. Quantitative assessment showed that Kjeldahl nitrogen were in range of 0.11 to 28.05 mg/L; ammonium 0.50 to 20.22 mg/L, nitrate from 0.12 to 22.69 mg/L and nitrite from 0.15 to 3.90 mg/L. Parameters decreased from early to late rain, which can be attributed to rain dilution factor potential, wind pattern and emission from anthropogenic sources that influenced the rainwater quality across surfaces. Nitrogen results showed that dry and wet deposition has great impact; atmospheric aerosols and biogeochemical interactions can affect water quality. Monthly variation showed that Ogale had high regression compared to other locations due to close proximity to oil and gas emission and marine contribution. Neutralization factor showed that nitrate-nitrite compounds have strong correlation with ammonium ion. Non-carcinogenic risk assessment using US EPA model showed hazard index less than one (1), thus no associated health effect of nitrate and nitrite in rainwater. In conclusion, it is evident that nitrate/nitrite levels and other nitrogen derivatives in rainwater in crude oil-producing Niger Delta and its continuous consumption can cause negative health outcome.

Heavy metal exposure to a migratory waterfowl, Northern Pintail (Anas acuta), in two peri-urban wetlands.

In this study, the heavy metal exposure risk model was employed to assess the exposure risk to a predominantly herbivore waterfowl, Northern Pintail, wintering in two wetland habitats in the Purulia district of West Bengal, located on overlapping Central Asian Flyway (CAF) and East Asian-Australasian Flyway (EAAF). Both wetlands were important staging and roosting grounds for migratory waterfowl for ages. The exposure model was used to quantify the risk of exposure to metals through oral ingestion. Exposure doses of Cu, Zn, Pb, and Cr through food plants ingestion and food-associated sediment consumption pathways were two potent sources of heavy metal exposure in the waterfowl under study. Exposure through water intake was ignored as metals were either of negligible concentrations or below the detection limit in water samples. Heavy metal concentrations showed significant positive correlations between bottom sediment and plant at both sites. At Purulia Sahebbandh (Site 1), the total exposure dose of all four metals was much higher than their conforming tolerable daily intake (TDI), and thereby, the metals might pose threats to the migratory wintering herbivorous waterfowl populations. However, in Adra Sahebbandh (Site 2), total exposure doses of Pb, Zn and Cu were much below their corresponding TDI. The Hazard Quotient (HQ) of Cr was highest followed by nonessential toxic Pb and these two elements could be considered as priority pollutants at Site 1. Prioritize threats were decreased in the following sequence: Cr > Pb > Cu > Zn at Site 1 and Cr > Zn > Pb > Cu at Site 2. Hazard Index was found to be >5 at Site 1 and for much higher metal loads a significant correlation between metal concentrations in plants, bottom sediment and exposure doses were also recorded. Therefore, the peri-urban Purulia Sahebbandh wetland could immediately be considered for risk control and demanded holistic management of important waterfowl habitats.

Hydrochemical evaluation of groundwater quality and human health risk assessment of trace elements in the largest mining district of South Khorasan, Eastern Iran.

The groundwater resources of mining areas have been in a challenging condition in terms of metal pollution and human health. Therefore, this study investigated the concentration of cobalt (Co), molybdenum (Mo), selenium (Se), tin (Sn), and antimony (Sb) in groundwater samples (wells, qanats, and springs) in a heavily contaminated mining district, South Khorasan, Eastern Iran. Human health risk of the studied metals to target groups was assessed, and water quality of the studied groundwater was investigated in the study area. A total of 367 sampling sites (279 wells, 74 qanats, and 14 springs) in South Khorasan Province were selected to collect the groundwater samples from June to July 2020. Sampling was performed thrice for each sampling point, and hydrochemical parameters were evaluated using a portable multiparameter. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect the metal concentrations. Results showed an order of Se > Mo > Sn > Co > Sb, and hazard index (HI) demonstrated a warning condition for south of South Khorasan (drinking application), southwest of South Khorasan (Irrigation application), and east and center of South Khorasan (drinking-irrigation application). Hydrochemical parameters showed a classification of "Na + K type" and "Mixed Ca-Mg-Cl type" with an overall group of "Na-Cl-HCO3" for sampled waters. Ficklin-Caboi diagram depicted a classification of "near-neutral low metal," and Schoeller diagram classified studied groundwater as "good" for drinking and irrigation consumptions and "Na-Cl" type based on ion balance diagram. Based on the correlation analysis, positive relationships were recorded among EC, TDS, Cl-, Na+, sulfate, Ca2+, salt, total hardness, Mg2+, ammonia, and K+ measured in the water samples. In essence, arid regions of the world greatly rely upon groundwater resources for drinking and irrigation consumptions, and mining districts with a heavy load of active mines can be a serious threat to the groundwater quality and human health.

Detection and Risk Assessments of Multi-Pesticides in Traditional Chinese Medicine Chuanxiong Rhizoma by LC/MS-MS and GC/MS-MS.

With the internationalization of traditional Chinese medicines (TCMs) and the increasing use of herbal medicines around the world, there are concerns over their safety. In recent years, there have been some sporadic reports of pesticide residues in Chuanxiong Rhizoma (CX), although the lack of systematic and comprehensive analyses of pesticide residues and evaluations of toxicological risks in human health has increased the uncertainty of the potential effects of pesticides exposure in humans. This study aimed to clarify the status of pesticide residues and to determine the health risks of pesticide residues in CX. The findings of this study revealed that 99 batches of CX samples contained pesticide residues ranging from 0.05 to 3013.17 µg/kg. Here, 6-22 kinds of pesticides were detected in each sample. Prometryn, carbendazim, dimethomorph, chlorpyrifos, chlorantraniliprole, pyraclostrobin, and paclobutrazol were the most frequently detected pesticides, with detection rates of 68.69-100%. Insecticides and fungicides accounted for 43.23% and 37.84% of the total pesticides detected, respectively. Here, 86.87% of the pesticide content levels were lower than 50 µg/kg, and a small number of samples contained carbofuran, dimethoate, and isofenphos-methyl exceeding the maximum residue levels (MRLs). A risk assessment based on the hazard quotient/hazard index (HQ/HI) approach revealed that the short-term, long-term, and cumulative risks of pesticide residues in CX are well below the levels that may pose a health risk. Worryingly, six banned pesticides (carbofuran, phorate sulfone, phorate-sulfoxide, isofenphos-methyl, terbufos-sulfone, and terbufoxon sulfoxide) were detected. This study has improved our understanding of the potential exposure risk of pesticide multi-residues in CX. The results of the study will have a positive impact on improving the quality and safety of CX and the development of MRLs for pesticide residues.

Analysis of honey bee exposure to multiple pesticide residues in the hive environment.

Since the loss of honeybees in hives could have a greater impact on colony health than those of their foraging bees, it is imperative to know beehives' pesticide exposure via oral ingestion of contaminated in-hive matrices. Here, a 4-year monitoring survey of 64 pesticide residues in pollen, nectar and related beehive matrices (beebread and honey) from China's main honey producing areas was carried out using a modified version of the QuEChERS multi-residue method. The results showed that 93.6% of pollen, 81.5% of nectar, 96.6% of beebread, and 49.3% of honey containing at least one target pesticide were detected either at or above the method detection limits (MDLs), respectively, with up to 19 pesticides found per sample. Carbendazim was the most frequently detected pesticide (present in >85% of the samples), and pyrethroids were also abundant (median concentration = 134.3-279.0 µg/kg). The transfer of pesticides from the environment into the beehive was shown, but the pesticide transference ratio may be affected by complex factors. Although the overall risk to colony health from pesticides appears to be at an acceptable level, the hazard quotient/hazard index (HQ/HI) value revealed that pyrethroids were clearly the most influential contributor, accounting for up to 45% of HI. Collectively, these empirical findings provide further insights into the extent of contamination caused by agricultural pesticide use on honeybee colonies.

Analysis of dietary exposure and risk assessment of pesticide residues in roots and rhizomes of Chinese herbs.

Medicine food homologous (MFH) plants provide therapeutic and health care effects through diet. Thus, a risk assessment system for hazardous ingredient residues is urgently required to ensure their safe use. In this study, the pesticide contamination of six root and rhizome Chinese herbs, Ginseng Radix et Rhizoma, Panacis Quinquefolii Radix, Pseudostellariae Radix, Salviae Miltiorrhizae Radix et Rhizoma, Codonopsis Radix, and Glehniae Radix, and the risks associated with their intake were investigated. A total of 420 MFH plant samples collected from 22 provinces in China were tested, and 61 pesticides were detected in 413 samples. Multiple pesticide residues were detected in each MFH sample, with contents ranging from 0.0002 to 3.010 mg/kg dry weight. Carbendazim (≥47.14%) and propham (≥40%) were the most frequently detected pesticides. Risk assessment determined by hazard quotients indicated that the risks were acceptable, with no short- or long-term adverse health effects. However, considering the high incidence of residues and the detection of unregistered or even prohibited pesticides, strict supervision of soil quality and pesticide application (particularly cadusafos) in MFH plant cultivation are recommended to aid in monitoring MFH plant quality and ensuring diet and drug safety. PRACTICAL APPLICATION: Ensure the diet and drug safety of Chinese herbs.

Heavy metal and essential elements in beers from turkey market: A risk assessment study.

In this study, the level of arsenic (As), lead (Pb) and cadmium (Cd) and also essential elements in beer samples consumed in Turkey were investigated using the inductively coupled plasma mass spectrometry (ICP-MS) method. The heavy metal-induced non-carcinogenic and carcinogenic risks were calculated. For essential elements, the calculated estimated daily intake of iron (Fe), copper (Cu), selenium (Se) and cobalt (Co) from beer consumption were compared with their toxicity reference values. Tukey post-hoc test showed that As was found at a significantly higher level when compared to Pb. Also, a significant correlation was found between As level and alcohol by volume percent. All samples had a hazard quotient and hazard index <1, indicating no non-carcinogenic risk from exposure to single or multiple heavy metals. Some samples exceeded the threshold limit of acceptable cancer risk for As in the high beer consumer group. This assessment showed that in addition to health implications based on the alcohol content of beer, there might be a carcinogenic risk associated with the heavy metals content of these beverages.

Investigation of toxic heavy metals content and estimation of potential health risks in Chinese herbal medicine.

The content of toxic heavy metals (THMs), including lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg), was determined in a total of 10,245 samples for 279 types of Chinese herbal medicine (CHM) using a validated inductively coupled plasma mass spectrometry method. The exceeding rate (ER) for the four THMs were calculated based on diverse permissible limits (PLs) established by different organizations and national pharmacopeias. Cluster analysis was used to classify the degree risk of THMs contamination according to the calculated ER. Results revealed that Cibotii rhizome, Selaginellae herba, Morindae officinalis radix, Asprellae ilicis radix, and Toxicodendri resina exhibited high-degree risk of Pb contamination. Eckloniae/Laminariae thallus, Spirodelae herba, and Naturalis indigo possessed high-degree risk of As contamination. Tetrapanacis medulla, Centipedae herba, Cyathulae radix, Linderae radix, Meretricis/Cyclinae concha, and Tabanus displayed high-degree risk of Cd contamination. Toxicodendri resina has high-degree risk of Hg contamination. In addition, six types of CHM, including Asprellae ilicis radix, Toxicodendri resina, Eckloniae/Laminariae thallus, Fossilia Ossis Mastodi, Haematitum, and Hedyotidis diffusae herba, may have non-carcinogenic health risk after consumption of raw materials because the calculated hazard quotient and hazard index were over 1.0. In summary, these data provide useful information about THMs contamination in CHM.

Geographical origin differentiation of Chinese Angelica by specific metal element fingerprinting and risk assessment.

Traceability offers significant information about the quality and safety of Chinese Angelica, a medicine and food homologous substance. In this study, a systematic four-step strategy, including sample collection, specific metal element fingerprinting, multivariate statistical analysis, and benefit-risk assessment, was developed for the first time to identify Chinese Angelica based on geographical origins. Fifteen metals in fifty-six Chinese Angelica samples originated from three provinces were analyzed. The multivariate statistical analysis model established, involving hierarchical cluster analysis (HCA), principal component analysis (PCA), and self-organizing map clustering analysis was able to identify the origins of samples. Furthermore, benefit-risk assessment models were created by combinational calculation of chemical daily intake (CDI), hazard index (HI), and cancer risk (CR) levels to evaluate the potential risks of Chinese Angelica using as traditional Chinese medicine (TCM) and food, respectively. Our systematic strategy was well convinced to accurately and effectively differentiate Chinese Angelica based on geographical origins.

Food Supplements for Weight Loss: Risk Assessment of Selected Impurities.

Nowadays, food supplements are widely consumed, often without any medical supervision. In this study, 25 food supplements for weight loss, randomly purchased from five different suppliers in the European Union, were analysed by Wavelength Dispersive X ray Fluorescence spectrometry (WDXRF). The aim of this study was the risk assessment of trace elements and the mixture of elements present in food supplements for weight loss. The obtained Hazard Index (0.11) showed no potential risk of non-carcinogenic effects to human health. However, since humans are frequently exposed by different routes and/or sources to toxic metals, the additional consumption of these products may cause potential toxicological risks that cannot be ignored. In one analysed food supplement (FS), the simultaneous presence of Pb and Mn in high concentrations was detected. In two, FS chromium concentrations were above the reference daily dose. Unconformities were detected between the labelled and the detected values, which emphasises the misinformation of labels. This highlights the need for a deeper surveillance of food supplements.

Systematic probabilistic risk assessment of pesticide residues in tea leaves.

Multiple pesticide residues are frequently present in tea leaves and while the majority of residues satisfy Taiwan's current health regulations, there are potential health effects from pesticide exposure that are of great concern for tea drinkers. We undertook a systematic probabilistic risk assessment of 59 pesticides in tea leaves from 1629 tea leaf samples obtained by Taiwan's Food and Drug Administration in two monitoring surveys in 2015. Bayesian statistics used a Markov Chain Monte Carlo approach to estimate posterior distributions of pesticide residues in tea leaves, lifetime average daily doses and hazard quotients (HQs) of evaluated pesticides. We classified 95th percentile values of HQs into three categories: 0 < HQ < 0.5, 0.5 ≤ HQ ≤ 1 and 1 < HQ. The 95th percentiles of HQs for triazophos (3.39), carbofuran (2.04) and endosulfan (1.80) exceeded 1 in the adult population; the HQ for 3-OH carbofuran was 0.97 and was less than 0.5 for the remaining 55 pesticides. The health risk posed by pesticide residues for tea drinkers is negligible, if triazophos, carbofuran, endosulfan, and 3-OH carbofuran residues satisfy regulatory standards. However, five legacy pesticides, DDT, methomyl, carbofuran, dicofol and endosulfan, were identified. To reduce uncertainties, this study combined Bayesian statistics with a mode of action approach for systematic risk assessment of co-exposure to multiple pesticide residues in tea leaf samples. Measuring pesticide transfer rates will improve the quality of future risk assessments concerning residues in tea leaves. Appropriate management of pesticides in Taiwanese tea farms and monitoring of pesticide residues in imported tea is warranted to protect Taiwan's tea drinkers.

Cumulative risk assessment of phthalates in edible vegetable oil consumed by Chinese residents.

BACKGROUND: Phthalates have been widely used as plasticizers in various industries and are widely focused on in the international community as a result of their reproductive toxicity. Exposure of Chinese residents to phthalates via edible vegetable oil occurs often. In the present study, gas chromatography-mass spectrometry was used to detect the two main phthalates bis(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) in four major edible vegetable oil sources: an edible oil blend, soybean oil, peanut oil and rapeseed oil (a total of 1016 samples), as collected throughout China. Furthermore, cumulative risk assessment was used to estimate the reproductive health risk to Chinese residents caused by the phthalates that come from edible vegetable oils. RESULTS: Both phthalates were detected in four major edible vegetable oil sources. The phthalate with the highest detection rate was DBP (13.48%), followed by DEHP (7.78%). The results of the cumulative risk assessment showed that the hazard indices of these two phthalates in edible vegetable oils were less than 1, except in soybean oil. Nevertheless, the two phthalates had the lowest detection rates in soybean oil, which were 1.94% (DEHP) and 5.16% (DBP). In China, contamination levels of phthalates in the soils where oil crops are cultivated have a great influence on the phthalate concentrations in edible vegetable oils. CONCLUSION: It is recommended that Chinese residents who are consuming soybean oil choose well-known brands and regularly change their brand of consumption. The phthalates in edible vegetable oils pose a relatively small reproductive health risk to Chinese residents. © 2019 Society of Chemical Industry.

Heavy metal content and health risk assessment of commonly patronized herbal medicinal preparations from the Kumasi metropolis of Ghana.

PURPOSE: To address the question of whether users of herbal products (HPs) are exposed to harmful contaminants, we evaluated six HPs mostly patronized in Kumasi for heavy metal contamination and assessed the health risk associated with their use. This study is one of the first safety evaluation studies on finished multiherbal products in the region. METHOD: Three antimalarial, two antidiabetic and one antihypertensive HPs were selected after a mini-survey and coded randomly as HP A-F. The HPs were acid digested for quantitative analysis of heavy metals using Inductively Coupled Plasma Mass Spectrometer. Hg quantification was carried out using cold vapour atomic absorption spectroscopy. RESULTS: The cancer risk estimation values for the carcinogenic metals ranged between 1.54 × 10-9 to 3.73 × 10-4 and were all within acceptable limits. The non-cancer health risk evaluation revealed that, some of the products pose health risk to consumers. The estimated daily intake (EDI) for As in HPF was 2.48 × 10-4 mg/kg/day compared to the reference limit of 1.67 × 10-4 mg/kg/day. HPF also had high hazard index (HI) of 5.70 (HI >1) in children as compared to 1.68 (HI >1) in adults showing a 3.4 folds increase in the health risk among the former. CONCLUSION: The six polyherbal products exhibited carcinogenic risk within acceptable limits. Although, the non-carcinogenic risk assessment of products HPA to HPE suggests safety, this can only be ascertained after further characterization of their health risks in detailed chronic toxicity studies. The high HI for product HPF suggests health risk for consumers of this product.

Analysis of exposure to pesticide residues from Traditional Chinese Medicine.

The safety of Traditional Chinese Medicine (TCM) is of concern worldwide. Herein, Paeoniae Radix Alba, Chaenomelis Fructus and Moutan Cortex, representing three medicinal components, were subjected to toxicological analysis to investigate possible pesticide contamination. Exposure using a point estimate model identified 47 residues that were simultaneously validated by the QuEChERS-UPLC-MS/MS method, which is sufficiently reliable for measuring residue concentrations. Of the 313 samples tested, 94.57% contained pesticide residues, with concentrations ranging from 0.10 to 1199.84 µg kg-1, of which >83.17% contained 4-15 different residues. Carbendazim was the most frequently detected pesticide (>85%), and procymidone, pendimethalin and phoxim were also abundant (median concentration = 15.33-623.12 µg kg-1). Risk assessment based on the hazard quotient/hazard index (HQ/HI) approach revealed that exposure to pesticide residues in all three TCMs (95th percentile) were far below levels that might pose a health risk. However, insecticides contributed to cumulative exposure, especially phoxim, and worryingly, several banned pesticides were detected. The results are of theoretical and practical value for evaluating the safety TCMs, and could improve their quality and safety.

Mixture risk assessment due to ingestion of arsenic, copper, and zinc from milkfish farmed in contaminated coastal areas.

Human health risks associated with the consumption of metal-contaminated fish over extended periods have become a concern particularly in Taiwan, where fish is consumed on a large scale. This study applied the interaction-based hazard index (HI) to assess the mixture health risks for fishers and non-fishers who consume the arsenic (As), copper (Cu), and zinc (Zn) contaminated milkfish from As-contaminated coastal areas in Taiwan, taking into account joint toxic actions and potential toxic interactions. We showed that the interactions of As-Zn and Cu-Zn were antagonistic, whereas As-Cu interaction was additive. We found that HI estimates without interactions considered were 1.3-1.6 times higher than interactive HIs. Probability distributions of HI estimates for non-fishers were less than 1, whereas all 97.5%-tile HI estimates for fishers were >1. Analytical results revealed that the level of inorganic As in milkfish was the main contributor to HIs, indicating a health risk posed to consumers of fish farmed in As-contaminated areas. However, we found that Zn supplementation could significantly decrease As-induced risk of hematological effect by activating a Zn-dependent enzyme. In order to improve the accuracy of health risk due to exposure to multiple metals, further toxicological data, regular environmental monitoring, dietary survey, and refinement approaches for interactive risk assessment are warranted.

Association between Aluminum and Silicon Concentrations in Isfahan Drinking Water and Their Health Risk Assessments.

BACKGROUND: High concentrations of elements such as aluminum (Al) and silicon (Si) in drinking water can affect human health. It is suggested that high daily intake of Al is associated with increased risk of neurodegenerative disorders. Si, as an antidote of Al, may decrease Al bioavailability. The study was conducted to estimate Al and Si concentration and correlation in water and evaluate their health risk. METHODS: In this cross-sectional study, water samples were collected from 20 points of water distribution system and the water treatment plant of Isfahan in spring and summer. Samples were analyzed using DR-5000. The health risk was evaluated via calculating chronic daily intake (CDI) and hazard index (HI). RESULTS: Significant negative correlation was documented between Al and Si (R = -0.482, P = 0.037 in spring, and R = -0.452, P = 0.049 in summer). These values were approximately similar in all types of Al and Si. The amounts of CDI for Al in spring and summer were 6.67E-04 and 0.002 mg/kg/day, respectively. The Al HI values were below 1 in both seasons. CONCLUSIONS: The significant correlation between Al and Si concentrations suggests that Si can eliminate Al in water, and probably it might do the same in the body. The health risk of Al intake from tap water was negligible, it was assessed in an acceptable range with an HI value of less than the standard levels. The health risk of Si remained unknown due to lack of information regarding its toxicity and adverse health effects.

Exploration of the spatial-Composite Risk Index (CRI) for the characterization of toxicokinetics in petrochemical active areas.

The spatial modeling of the petrochemical active regions in the Niger Delta (ND), Nigeria was carried out through the analysis exploration and extraction of geospatial data and resultant risk maps were generated. The pollutants assessed include; heavy metals, polychlorinated aromatic hydrocarbons (PAHs), benzene-toluene-ethylene-xylene (BTEX), and total petroleum hydrocarbons (TPHs) and properties of the pollutants such as bioaccumulation, persistence and toxicity were used to calculate the Hazard Index (HI) and thus created a ranking system. The Composite Risk Index (CRI) was developed successively considering the concentrations of all pollutants and the computed HI using the samples collected in ND areas of Nigeria. The carcinogenic PAHs showed spatial abundance in the areas sampled and elevated levels of soil heavy metals were also observed. In this study, mathematical tool such as the artificial neural network (ANN) self-organizing map (SOM) and geostatistical analysis such as kriging were applied to develop the risk map of the areas which represent the spatial spread of the CRI. The results show that the application of spatially developed integral risk map for pollutant assessment is effective and facilitates with decision making with regards the environment and humans exposed in this region.