Arsenic Induced Gallbladder Cancer Risk in Eastern Part of Indo-Gangetic Plains

BackgroundIn recent times Gallbladder cancer (GBC) incidences increased many folds in India. Majority of GBC cases are being reported from arsenic hotspots identified in Bihar. MethodsIn this prospective study volunteers were selected who underwent surgery in our cancer institute. There were 11 control benign gallbladder cases and 28 confirmed gallbladder cancer cases. Their biological samples such as blood, gallbladder tissue, gallbladder stone, bile and hair samples were collected for arsenic estimation. Moreover, n=512 gallbladder cancer patients blood samples were evaluated for the presence of arsenic to understand exposure level in the population. ResultsA significantly high arsenic concentration (p<0.05) was detected in the blood samples, gallbladder tissue, gallstones, bile and hair samples in comparison to the control group. Moreover, n=512 blood samples of GBC patients had significantly very high arsenic concentration. ConclusionsThe study shows very high arsenic concentration observed in the blood, gallbladder tissue, gallbladder stone, bile and hair samples in GBC cases in comparison to the benign control cases indicates the correlation between chronic arsenic exposure and gallbladder cancer incidences in eastern Indo-Gangetic plains region. The study also makes an attempt to establish the likely correlation/association between arsenic exposure and gallbladder cancer disease.

Health risk assessment of arsenic in drinking groundwater: A case study in a central high land area of Vietnam

Arsenic contaminated groundwaters is a global environmental issue which cause serious problems for human health risks. 188 groundwater samples were collected in private wells of Lam Dong Province, a central highland area, Vietnam to investigate the health risks to the local people by using arsenic contaminated groundwater for drinking purpose. The result showed that the arsenic concentration is average of 14 μg/L and maximum of 500 μg/L. About 12% out of the total groundwater samples have arsenic concentration exceeded that value of 10 μg/L recommended for drinking water by World Health Organization (WHO, 2019). The health risk assessment showed that hazard quotient (HQ) value for adults was up to 60.6 with an average of 1.7 and about 14% of total samples show the HQ values greater than 1. The HQ value for children is average of 4.7 (maximum of 166.7) and about 23% of total groundwater samples show HQ > 1 for children. Cancer risk (CR) values were up to 27x10-4 (average of 8x10-4) for adults and 75x10-4 (average of 21x10-4) for children. About 26% and 29% of out of the total samples show CR value for adult and children greater than the CR (1×10-4) proposed by the USEPA. The result also indicated that the consumption of arsenic contaminated groundwater may seriously damage the human health. Therefore, groundwater in the area needs to be treated for arsenic removal before drinking to minimize the adverse effect on local communities’ health.

Variation in Arsenic metabolism in schistosomiasis associated bladder pathology in a rural community, Eggua, Ogun State, Nigeria

Exposure to toxic inorganic Arsenic (iAs) in areas endemic for urogenital schistosomiasis may confer increased risk for bladder cancer. The severity of the adverse effects of iAs however depends on its metabolism, which is highly variable among individuals. Genetic polymorphism in Arsenic (+3) Methyl Transferase enzyme, accounts significantly for these variations. To investigate the relationship of AS3MT gene polymorphisms and Arsenic metabolism to schistosomiasis and/or associated bladder pathology, 119 individualsfrom Eggua in southwest Nigeria were recruited for this study. Screening for schistosomiasis and bladder pathology was done by microscopy and ultrasonography respectively. Wagtech Digital Arsenator was used to assess total urinary arsenic concentrations and thus determine the level of arsenic exposure. The single nucleotide polymorphism AS3MT/Met287Thr T>C (rs11191439) was genotyped using Alelle-Specific PCR. Of the participants who tested positive for schistosomiasis, 33.3% exhibited bladder pathology. Total urinary arsenic concentration in 80% of the participants was above the WHO limit of 0.05mg/L. The Met287Thr allelic distribution conformed to the Hardy-Weinberg equilibrium (X2= 0.161, P> 0.05). Observed allelic frequencies were 0.96 and 0.04 for wild-type T and mutant C alleles respectively. There was no significant relationship between AS3MT SNP, arsenic concentrations and schistosomiasis associated bladder pathology. In conclusion, the community is highly exposed to arsenic, although with a possible genetic advantage of increased AS3MT catalytic activity. However, we see the need for urgent intervention as inter-individual differences in arsenic metabolism may influence the bladder pathology status of individuals in the community. And although urogenital schistosomiasis is waning in Eggua, it is not known what synergy the infection and high arsenic exposure may wield on bladder pathology.

Microwave Soil Treatment along with Biochar Application Alleviates Arsenic Phytotoxicity and Reduces Rice Grain Arsenic Concentration

Rice grain arsenic (As) is a major pathway of human dietary As exposure. This study was conducted to reduce rice grain As concentration through microwave (MW) and biochar soil treatment. Collected soils were spiked to five levels of As concentration (As-0, As-20, As-40, As-60, and As-80 mg kg−1) prior to applying three levels of biochar (BC-0, BC-10, and BC-20 t ha−1) and three levels of MW treatment (MW-0, MW-3, and MW-6 min). The results revealed that MW soil treatment alleviates As phytotoxicity as rice plant growth and grain yield increase significantly and facilitate less grain As concentration compared with the control. For instance, the highest grain As concentration (912.90 µg kg−1) was recorded in the control while it was significantly lower (442.40 µg kg−1) in the MW-6 treatment at As-80. Although the BC-10 treatment had some positive effects, unexpectedly, BC-20 had a negative effect on plant growth, grain yield, and grain As concentration. The combination of BC-10 and MW-6 treatment was found to reduce grain As concentration (498.00 µg kg−1) compared with the control (913.7 µg kg−1). Thus, either MW-6 soil treatment alone or in combination with the BC-10 treatment can be used to reduce dietary As exposure through rice consumption. Nevertheless, further study is needed to explore the effectiveness and economic feasibility of this novel technique in field conditions.

Detecting Arsenic Contamination Using Satellite Imagery and Machine Learning

Arsenic, a potent carcinogen and neurotoxin, affects over 200 million people globally. Current detection methods are laborious, expensive, and unscalable, being difficult to implement in developing regions and during crises such as COVID-19. This study attempts to determine if a relationship exists between soil’s hyperspectral data and arsenic concentration using NASA’s Hyperion satellite. It is the first arsenic study to use satellite-based hyperspectral data and apply a classification approach. Four regression machine learning models are tested to determine this correlation in soil with bare land cover. Raw data are converted to reflectance, problematic atmospheric influences are removed, characteristic wavelengths are selected, and four noise reduction algorithms are tested. The combination of data augmentation, Genetic Algorithm, Second Derivative Transformation, and Random Forest regression (R2=0.840 and normalized root mean squared error (re-scaled to [0,1]) = 0.122) shows strong correlation, performing better than past models despite using noisier satellite data (versus lab-processed samples). Three binary classification machine learning models are then applied to identify high-risk shrub-covered regions in ten U.S. states, achieving strong accuracy (=0.693) and F1-score (=0.728). Overall, these results suggest that such a methodology is practical and can provide a sustainable alternative to arsenic contamination detection.

Separation and Stabilization of Arsenic from Lead Slime by the Combination of Acid Leaching and Forming Scorodite

In this paper, a scheme is proposed for the treatment of arsenic-containing lead slime by the combination of acid pressure oxidation leaching and forming scorodite. On the basis of thermodynamic calculations, the effects of six factors including acid concentration, oxygen partial pressure (pO2), liquid to solid ratio (L/S), agitating speed, leaching time and temperature for the removal of arsenic were studied in an acid pressure oxidation leaching process, then the optimum leaching conditions were established: L/S of 10 mL/g, leaching time of 2.5 h, pO2 of 2.0 MPa, leaching temperature of 170 °C, acid concentration of 100 g/L and stirring speed of 300 r/min. Under the optimal conditions, the leaching rate of arsenic from lead slime reached 99.10% and the arsenic content of the leaching residue was about 0.80%. After a decontamination procedure, the total arsenic concentration in the acid solution obtained from leaching experiments was 37.18 g/L, and the initial pH was 0.50. Finally, as high as 98.5% of arsenic extracted from the lead slime was stabilized in the form of scorodite (FeAsO4·2H2O) by the precipitation process under the following conditions: initial pH value of 1.0, Fe(II)/As molar ratio of 1.3, pO2 of 2.5 MPa, temperature of 160 °C and precipitation time of 2.0 h.

Variations of arsenic in groundwater from a transect in Van Phuc village, Hanoi

In this study, the author report detailed results of the variation of arsenic in groundwater along a transect in an area near the Hanoi city centre. The results showed that 64% of collected samples exceeded the WHO guideline value for arsenic concentration in drinking water. The arsenic concentration varied in a wide range, strongly depending on the sediment characteristics of each zone along the transect. Aside from As, groundwater in this area also was contaminated by elevated concentrations of Fe, Mn, and ammonium. The study also pointed out a positive correlation between As and reductive chemical species, namely DOC, NH4+, and CH4 in groundwater. Although there is no clear trend in the correlation between As and Fe, Mn, it can be concluded that the formation of arsenic in groundwater in the study area was due to the reductive dissolution of As-bearing iron minerals under the presence of organic matter.