Exposure to heavy metal contamination and probabilistic health risk assessment using Monte Carlo simulation: a study in the Southeast Iran

The rice contamination to heavy metals and its associated health risks have been less addressed in the southeast of Iran. In the present study, in the mentioned region, we assessed the concentration of nine elements in rice, and the health risk related to the measured elements was determined using the data which were gathered by a questionnaire. For this purpose, 36 samples of the 12 most widely consumed rice brands were collected. Using ICP-MS, the concentrations of Ni, Cr, Hg, Sr, Mn, Fe, Se, Ba, and Zn were measured in the studied samples as 0.599 ± 0.124, 0.483 ± 0.28, 0.0157 ± 0.005, 0.85 ± 1.307, 11.5 ± 1.97, 178.46 ± 67.27, 0.212 ± 0.083, 0.845 ± 0.62, and 8.416 ± 1.611 mg/kg, respectively. We found that, regarding the other studies, the levels of Ni, Cr, Hg, Fe, and Ba were higher. Besides, using 258 distributed questionnaires among citizens, the daily rice consumption was determined to be 295.66 ± 171.005 g/person/ day. Based on this consumption rate and Monto Carlo uncertainty simulation, Fe (0.741 ± 0.54 mg/kg/day) and Se (8.95E-04 ± 6.33E-04 mg/kg/day) showed the highest and lowest daily intake, respectively. Also, using Hazard Quotient (HQ), the non-carcinogenic risk effects of the surveyed elements were estimated. The obtained results of HQ revealed that Fe (2.48) and Mn (1.06) could pose non-carcinogenic health risks to consumers. Moreover, the calculated hazard Index showed that the overall health risk of the surveyed elements is in an unsafe range. © 2020, Springer Nature Switzerland AG

Association between colorectal cancer and Fusobacterium nucleatum and Bacteroides fragilis bacteria in Iranian patients: a preliminary study

Background and aim: Recent studies have proposed that commensal bacteria might be involved in the development and progression of gastrointestinal disorders such as colorectal cancer (CRC). Therefore, in this study, the relative abundance of Fusobacterium nucleatum, Bacteroides fragilis, Streptococcus bovis/gallolyticus, and Enteropathogenic Escherichia coli (EPEC) in CRC tissues, and their association with clinicopathologic characteristics of CRC was investigated in Iranian patients. Moreover, the role of these bacteria in the CRC-associated mutations including PIK3CA, KRAS, and BRAF was studied. Method: To these ends, the noted bacteria were quantified in paired tumors and normal tissue specimens of 30 CRC patients, by TaqMan quantitative Real-Time Polymerase Chain Reaction (qPCR). Next, possible correlations between clinicopathologic factors and mutations in PIK3CA, KRAS, and BRAF genes were analyzed. Results: In studied samples, B. fragilis was the most abundant bacteria that was detected in 66 and 60 of paired tumor and normal samples, respectively. Furthermore, 15 of the B. fragilis-positive patients were infected with Enterotoxigenic B. fragilis (ETBF) in both adenocarcinoma and matched adjacent normal samples. F. nucleatum was also identified in 23 of tumors and 13 of adjacent normal tissue samples. Moreover, the relative abundance of these bacteria determined by 2-�CT was significantly higher in CRC samples than in adjacent normal mucosa (p < 0.05). On the other hand, our findings indicated that S. gallolyticus and EPEC, compared to adjacent normal mucosa, were not prevalent in CRC tissues. Finally, our results revealed a correlation between F. nucleatum-positive patients and the KRAS mutation (p = 0.02), while analyses did not show any association between bacteria and mutation in PIK3CA and BRAF genes. Conclusion: The present study is the first report on the analysis of different bacteria in CRC tissue samples of Iranian patients. Our findings revealed that F. nucleatum and B. fragilis might be linked to CRC. However, any link between gut microbiome dysbiosis and CRC remains unknown. © 2021, The Author(s)

Stochastic exposure and health risk assessment of rice contamination to the heavy metals in the market of Iranshahr, Iran

An investigation of some heavy metals content in rice (Oryza sativa) and associated health risks was carried out for residents of Iranshahr city, Iran. Average daily rice consumption of the citizens and most widely used rice brands in the market of Iranshahr were determined using a questionnaire. Besides, the concentration of heavy metals in the gathered rice samples was measured by inductively coupled plasma mass spectrometry (ICP-MS). Monte Carlo uncertainty simulation was utilized in conducting exposure assessment and investigating the non-carcinogenic effects of the studied elements as well as the carcinogenic effect of As. Concentrations of As, Cd, Pb, Cu, Al, and Mo were 0.369 ± 0.094, 0.0337 ± 0.039, 0.123 ± 0.14, 3.095 ± 439.42, 39.6 ± 14.73, and 1.106 ± 0.133 mg kg�1, respectively. Al (0.18 ± 0.15 mg kg�1 d�1) and Cd (0.00015 ± 0.00034 mg kg�1 d�1) were the highest and lowest estimated daily intake, respectively. Except As (5.23 ± 4.01), the calculated hazard quotient for investigated elements showed no non-carcinogenic health risk. Besides, the simulation of the carcinogenic risk effect for As (2.37E-3) revealed that the ingestion of the studied rice brands would cause cancer risk due to lifetime consumption. Results show that consumption of rice in the Iranshahr city is a potential source of exposure to the studied elements. © 2018 Elsevier Lt

Stochastic exposure and health risk assessment of rice contamination to the heavy metals in the market of Iranshahr, Iran

An investigation of some heavy metals content in rice (Oryza sativa) and associated health risks was carried out for residents of Iranshahr city, Iran. Average daily rice consumption of the citizens and most widely used rice brands in the market of Iranshahr were determined using a questionnaire. Besides, the concentration of heavy metals in the gathered rice samples was measured by inductively coupled plasma mass spectrometry (ICP-MS). Monte Carlo uncertainty simulation was utilized in conducting exposure assessment and investigating the non-carcinogenic effects of the studied elements as well as the carcinogenic effect of As. Concentrations of As, Cd, Pb, Cu, Al, and Mo were 0.369 ± 0.094, 0.0337 ± 0.039, 0.123 ± 0.14, 3.095 ± 439.42, 39.6 ± 14.73, and 1.106 ± 0.133 mg kg�1, respectively. Al (0.18 ± 0.15 mg kg�1 d�1) and Cd (0.00015 ± 0.00034 mg kg�1 d�1) were the highest and lowest estimated daily intake, respectively. Except As (5.23 ± 4.01), the calculated hazard quotient for investigated elements showed no non-carcinogenic health risk. Besides, the simulation of the carcinogenic risk effect for As (2.37E-3) revealed that the ingestion of the studied rice brands would cause cancer risk due to lifetime consumption. Results show that consumption of rice in the Iranshahr city is a potential source of exposure to the studied elements. © 2018 Elsevier Lt

Degradation of furfural in aqueous solution using activated persulfate and peroxymonosulfate by ultrasound irradiation

Furfural is a toxic compound that can cause many problems for human health and the environment. In this study, we addressed the degradation of furfural in aqueous solution using the activated persulfate (SPS) and peroxymonosulfate (PMS) through the ultrasonic (US) wave. Besides, the effect of various parameters (pH, oxidizing dose, initial furfural concentration, US frequency, Inorganic anions concentration, and scavenger) on SPS + US (SPS/US) and PMS + US (PMS/US) processes were examined. The results showed, in order to furfural removal, the US had excellent efficiency in activating SPS and PMS, as in SPS/US and PMS/US processes, 95.3 and 58.4 of furfural (at 25 mg/L concentration) was decomposed in 90 min, respectively. The furfural degradation rate increased with increasing oxidizing dose and US frequency in both SPS/US and PMS/US processes. Considering the synergistic effect, the best removal rate has occurred in the SPS/US process. In the SPS/US and PMS/US processes, furfural removal increased at natural pH (pH 7), and the presence of inorganic anions such as NO3 � and Cl� had negative effects on furfural removal efficiency. Also CO3 2� and HCO3 � acted as a radical scavenger in the SPS/US process but these anions in the PMS/US process produced more SO4 �° radicals, and subsequently, they increased the furfural degradation rate. The results also showed that the predominant radical in the oxidation reactions is the sulfate radical. This study showed that the SPS/US and PMS/US processes are promising methods for degrading organic pollutants in the environment. © 2020 Elsevier Lt

Stochastic exposure and health risk assessment of rice contamination to the heavy metals in the market of Iranshahr, Iran

An investigation of some heavy metals content in rice (Oryza sativa) and associated health risks was carried out for residents of Iranshahr city, Iran. Average daily rice consumption of the citizens and most widely used rice brands in the market of Iranshahr were determined using a questionnaire. Besides, the concentration of heavy metals in the gathered rice samples was measured by inductively coupled plasma mass spectrometry (ICP-MS). Monte Carlo uncertainty simulation was utilized in conducting exposure assessment and investigating the non-carcinogenic effects of the studied elements as well as the carcinogenic effect of As. Concentrations of As, Cd, Pb, Cu, Al, and Mo were 0.369 ± 0.094, 0.0337 ± 0.039, 0.123 ± 0.14, 3.095 ± 439.42, 39.6 ± 14.73, and 1.106 ± 0.133 mg kg�1, respectively. Al (0.18 ± 0.15 mg kg�1 d�1) and Cd (0.00015 ± 0.00034 mg kg�1 d�1) were the highest and lowest estimated daily intake, respectively. Except As (5.23 ± 4.01), the calculated hazard quotient for investigated elements showed no non-carcinogenic health risk. Besides, the simulation of the carcinogenic risk effect for As (2.37E-3) revealed that the ingestion of the studied rice brands would cause cancer risk due to lifetime consumption. Results show that consumption of rice in the Iranshahr city is a potential source of exposure to the studied elements. © 2018 Elsevier Lt

Preparation and photocatalytic performance of reduced graphene oxide/ ZnO nanocatalyst for degradation of metalaxyl from aqueous solution: effect of operational parameters, mineralisation and toxicity bioassay

A heterogeneous photocatalyst, ZnO/reduced graphene oxide (ZnO/rGO or ZG), was synthesised for the photocatalytic degradation of metalaxyl (MX) in aqueous solutions under UV irradiation. The characteristics of the prepared catalyst were determined by FTIR, XRD, FE-SEM, EDS, and BET analyses. The effect of various parameters such as solution pH, catalyst concentration, rGO loading in the catalyst structure, MX concentration and UV light intensity on the photodegradation of MX was investigated. The concentration of MX and the toxicity of the intermediates were determined by HPLC and the Daphnia Magna toxicity test, respectively. The effect of the water anions and radical scavenger compounds on the MX removal process was studied as well. The rate of mineralisation was determined by measuring the total organic carbon (TOC) value using the TOC analyser. The efficiency of the degradation process was compared with the real sample of agricultural drainage and deionised water. At optimum conditions (pH = 7, catalyst loading = 10, catalyst concentration = 0.75 g/l, MX concentration = 10 mg/l, and UV intensity = 220 MW/cm2), the removal and mineralisation rates were 90.25 and 51.17 after 120 min, respectively. Reactive species scavenging experiments showed that the hole was the most effective factor for MX degradation in the ZG/UV process. The MX degradation rate in real agricultural run-off samples showed that the degradation efficiency was 50.42, which was significantly lower than that of the synthetic samples. The toxicity bioassay by D. Magna indicated that the toxicity of MX was reduced from 51.22 to 15.17 after 96 h during the ZnO/rGO process. The photocatalytic efficiency decreased in the presence of phosphate and nitrate ions but did not change much in the presence of other water anions. Thus, the ZG/UV process can be effectively used for the degradation of organic pollutants, especially pesticides in wastewater. © 2020 Informa UK Limited, trading as Taylor & Francis Group

An overview report on the application of heteropoly acids on supporting materials in the photocatalytic degradation of organic pollutants from aqueous solutions

Organic pollutants contaminate water resources and the environment when discharged into water streams. Also, the presence of these materials in incompletely treated or untreated wastewater leads to serious environmental hazards. The hydroxyl radicals and holes are regarded as the most oxidant species in the degradation of organic pollutants using the studied composites. The results of this review show that heteropoly acids on supporting materials could be considered as appropriate photocatalysts in the removal of organic pollutant from aqueous solutions