Association of selenium, arsenic, and other trace elements in drinking water and urine in residents of the plateau region in China.

Drinking water is considered to be an important exposure pathway for humans to ingest trace elements; human urine samples are widely accepted as biometric substrates that can reflect human exposure to trace elements. The current study aimed at investigating the concentrations of trace elements including selenium (Se), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in drinking water and human urine in plateau region of China, determining the association among trace elements in drinking water and urine, and analyzing their associations with age and gender. The results showed that the majority of trace element concentrations were in the range of the World Health Organization (WHO 2011) guideline values, in both urine samples of male and female, and the median values were descending in the order: Zn > Cu > As > Se > Cr > Ni > Mn > Pb > Cd > Co. Selenium contributed to the excretion of As, Cr, Cu, Cd, and Zn in human body, group of 31-40 years appeared to present the greatest excretion ability in most of the trace elements. Weak positive correlations were observed between age and Mn in female urine samples, and negative correlations were observed between age and Se, As, Co, and Cu in male urine samples and between age and Co in female urine samples, respectively. Significant positive correlation was observed in As between drinking water and the whole human urine. In the same family, female seemed to show higher proportions of urinary As levels than male. This study will provide elementary information regarding trace element levels in drinking water and human urine in residents in plateau region of China and is helpful to provide reference for dietary nutrient trace element intake and effective control for local resident.

[Evaluation of dietary diversity of rural residents in Arun Banner, a typical area of low selenium belt in China].

OBJECTIVE: To understand the dietary diversity and food sources of different groups in Arun Banner. Comparing and analyzing the changes of dietary diversity of local residents in different periods. METHODS: In October 2019, according to the differences of Kashin-Beck disease conditions and land use patterns of Arun Banner, Hulun Buir, 78 rural residents were randomly selected from four villages to investigate the frequency of daily food consumption by using self-made food frequency questionnaire. Dietary diversity score(DDS) was used to evaluate the dietary diversity of different populations. RESULTS: The average DDS of the investigated residents was 9. 76±2. 32. DDS of the residents of Minzu and Tieshan villages(10. 14±2. 66) in the West was higher than that of Longtoushan and Hongqi villages(9. 42±1. 95) in the East. However, the difference was not statistically significant(Z=-1. 875, P& gt; 0. 05). DDS in males(10. 37±2. 47) was significantly higher than that in females(9. 36±2. 14)(P& lt; 0. 05). There was no significant difference in DDS(9. 52±2. 29) between Kashin-Beck disease affected patients and healthy residents(9. 85±2. 34)(Z=-0. 601, P& gt; 0. 05). There was no significant difference in DDS among different age groups. The average of DDS was higher in those younger than 60 years old(9. 90±2. 35). Residents mainly eat rice and flour, and the proportion of purchasing food from other places reaches 96% and 95%, respectively. CONCLUSION: The staple food in Arun Banner was mainly rice and flour purchased from other places. The dietary structure of residents tends to be diversified. Residents reduced dependence on low selenium natural environment is an important factor for local selenium-susceptible endemic diseases to be stable and gradually controlled.

Distribution and translocation of selenium from soil to highland barley in the Tibetan Plateau Kashin-Beck disease area.

Kashin-Beck disease (KBD), which is still active and severe in the Tibetan Plateau, is considered to be a kind of selenium (Se)-deficient disease. Highland barley as the most popular staple food in the Tibetan Plateau is one of the dominant Se sources for local people. To improve Se levels in crops in the Tibetan Plateau KBD area, the distribution and translocation of Se from soil to highland barley in both non-KBD and KBD endemic areas were investigated. The results showed that Se levels in highland barley were too low to meet the minimum requirements of human for daily intake of Se. The total Se concentrations of highland barley fractions in KBD areas were lower than that in non-KBD areas (grain P = 0.238; straw P = 0.087; root P = 0.008). However, no significant difference was observed in corresponding cultivated soil Se between the two areas (P = 0.993). The calculation of Se transfer factors indicated that the restricting step for Se translocation was from soil to root. Water-soluble, exchangeable and fulvic acid-bound Se fractions in the soil are key species dominating in this transfer process, according to their significant correlations with root Se. Se transfer from soil to root significantly increases as the pH value of soil increases (P = 0.007), and soil organic matter content decreases (P = 0.019). The information obtained may have considerable significance for proposing effective agricultural measures to increase grain Se in KBD endemic areas.

Levels of rare earth elements, heavy metals and uranium in a population living in Baiyun Obo, Inner Mongolia, China: a pilot study.

The Baiyun Obo deposit is the world's largest rare earth elements (REE) deposit. We aimed to investigate levels of REE, heavy metals (HMs) and uranium (U) based on morning urine samples in a population in Baiyun Obo and to assess the possible influence of rare earth mining processes on human exposure. In the mining area, elevated levels were found for the sum of the concentrations of light REE (LREE) and heavy REE (HREE) with mean values at 3.453 and 1.151 µg g(-1) creatinine, which were significantly higher than those in the control area. Concentrations of HMs and U in the population increased concomitantly with increasing REE levels. The results revealed that besides REE, HMs and U were produced with REE exploitation. Gender, age, educational level, alcohol and smoking habit were major factors contributing to inter-individual variation. Males were more exposed to these metals than females. Concentrations in people in the senior age group and those with only primary education were low. Drinking and smoking were associated with the levels of LREE, Cr, Cu, Cd and Pb in morning urine. Hence this study provides basic and useful information when addressing public and environmental health challenges in the areas where REE are mined and processed.

Predicting and verifying outcome of Tripterygium wilfordii Hook F. based therapy in rheumatoid arthritis: from open to double-blinded randomized trial.

Tripterygium wilfordii Hook F. (TwHF) based therapy has been proved as effective in treating rheumatoid arthritis (RA), yet the predictors to its response remains unclear. A two-stage trial was designed to identify and verify the baseline symptomatic predictors of this therapy. 167 patients with active RA were enrolled with a 24-week TwHF based therapy treatment and the symptomatic predictors were identified in an open trial; then in a randomized clinical trial (RCT) for verification, 218 RA patients were enrolled and classified into predictor positive (P+) and predictor negative (P-) group, and were randomly assigned to accept the TwHF based therapy and Methotrexate and Sulfasalazine combination therapy (M) for 24 weeks, respectively. Five predictors were identified (diuresis, excessive sweating, night sweats for positive; and yellow tongue-coating, thermalgia in the joints for negative). In the RCT, The ACR 20 responses were 82.61% in TwHF/P+ group, significantly higher than that in TwHF/P- group (P = 0.0001) and in M&S/P+ group (P < 0.05), but not higher than in M&S/P- group. Similar results were yielded in ACR 50 yet not in ACR 70 response. No significant differences were detected in safety profiles among groups. The identified predictors enable the TwHF based therapy more efficiently in treating RA subpopulations.

Speciation, distribution, and bioavailability of soil selenium in the Tibetan Plateau Kashin-beck disease area-a case study in Songpan County, Sichuan Province, China.

To clarify the relationship between the soil selenium distribution and its bioavailability with the distribution of Kashin-Beck disease (KBD) endemic areas on the eastern edge of the Tibetan Plateau, samples of natural soil (0-20 cm), cultivated topsoil, and main crops of the region (highland barley) were collected at different altitudes according to topographical and geomorphological features in both KBD and non-KBD areas of Songpan County. These samples were used for determination and analysis of total selenium content in soil and highland barley and available selenium that can be absorbed and utilized by plants. The results showed that the average total selenium content of natural and cultivated topsoil in KBD areas was lower than that in non-KBD areas (natural soil, P = 0.061; cultivated soil, P = 0.002), which is in agreement with the geographical distributions of selenium in other KBD-affected areas. However, the total soil selenium content exhibits certain micro-spatial distribution features, namely, the total selenium content in some endemic areas was significantly higher than that of non-KBD areas. This result was contrary to the general distribution that total selenium content in a KBD-affected area is lower than that in a non-KBD area. We further studied the extraction rate and content of soil selenium in six different fractions. The results indicated that the content and extraction rate of available selenium in KBD-affected areas were significantly lower than those in non-KBD areas. There is a distinct positive correlation between plant-available selenium and highland barley selenium (r = 0.875, P = 0.001) and a distinct negative correlation with altitude (r = -0.801, P = 0.010). Therefore, in KBD endemic areas, the selenium content in crops decreases as the available selenium content in soil decreases and is closely related to the geographical environment features (such as altitude and precipitation). These results suggest that the soil available selenium and ecological features are important factors that restrict the dietary selenium flux for residents in KBD endemic areas of the Tibetan Plateau, providing a theoretical and experimental basis for implementing agricultural measures to regulate the ecological cycle of the selenium flux in the KBD endemic area.