Potential health risk of areca nut consumption: Hazardous effect of toxic alkaloids and aflatoxins on human digestive system.

Contemporarily, there has been a growing consumption rate of areca nut (AN) products worldwide, despite the fact that both fresh and processed AN contain various hazardous ingredients, including toxic alkaloids and carcinogenetic aflatoxins. However, there is a dearth of toxicity and potential cancer risk information regarding toxic alkaloids and aflatoxins via consuming AN products. The present study conducted a comprehensive assessment of the combined hazardous effects of AN alkaloids and aflatoxins towards human digestive system, by methods of HPLC analysis, cell study and in vitro digestive system study. The results revealed a synergetic effect of arecoline and aflatoxins was on human gingival normal fibroblast cell of HGF-1 and a proliferation effect on human tongue squamous carcinoma cell of CAL-27. Specifically, the residual arecoline was as high as 91.08 µg·ml-1 in oral phase and 72.41 µg·ml-1 in gastric phase, which could be an evidence of oral cancer. More importantly, 25.93 % of AN products were contaminated with aflatoxins and the maximum value was three times the MRLs. Under these circumstances, the cytotoxic and MOE values raised a considerable health concern in terms of malignancy risk for children that consume processed AN product, especially compared to scenarios that involve adults and/or fresh AN samples. This study would give rise to a better understanding of the hazards associated with AN alkaloids and aflatoxins towards digestive system, and thus to predict the potential carcinogenic risk of AN products.

A new biochar from cotton stalks for As (V) removal from aqueous solutions: its improvement with H3PO4 and KOH.

The present study is the first attempt to evaluate the potential of acid and base activated biochar derived from cotton stalks (CSB) for the removal of As from contaminated water. The CSB was treated with 0.5 M KOH (BCSB) and H3PO4 (ACSB) separately to change its surface properties. The CSB, ACSB and BSCB were characterized using BET, FTIR, and SEM analysis to check the effectiveness and insight of the main mechanisms involved in the removal of As. A series of batch experiments was performed using As-contaminated synthetic water and groundwater samples. The effects of initial concentration of As, contact time, dose of the biochars, solution pH, type of the biochar and coexisting ions on the removal of As were investigated. Results revealed that BCSB efficiently removed As (90-99.5%) from contaminated water as compared with ACSB (84-98%) and CSB (81-98%) due to improved surface properties when As concentration was varied from 0.1 to 4.0 mg/L. The experimental data were best fitted with Freundlich adsorption isotherm as compared with Langmuir, Temkin and Dubinin-Radushkevich models. However, kinetic data were well explained with pseudo-second-order kinetic model rather than pseudo-first-order, intra-particle diffusion and Elovich models. The sorption energy indicated that physical adsorption was involved in the removal of As. The comparison of adsorption results with other biochars and their modified forms suggests that activation of CSB with base can be used effectively (4.48 mg/g) as a low-cost adsorbent for maximum removal of As from contaminated aqueous systems.