[Mercury Distribution Characteristics and Its Mass Balance in a Multifunctional Urban Wetland].

The distribution characteristics and the source-sink relationship of total mercury (THg) and methyl mercury (MeHg) were studied in a wastewater treatment area and in a lake deep purification area of a multifunctional urban wetland that integrates domestic sewage treatment plant effluent, water purification, and leisure entertainment in Chongqing. The results showed that the THg concentration ranged from 1.98 ng·L-1 to 38.03 ng·L-1[average concentration was (9.10±5.84) ng·L-1] and MeHg concentration ranged from 0.09 ng·L-1 to 0.84 ng·L-1[average concentration was (0.34±0.08) ng·L-1] in an outlet of wastewater treatment area. In the deep purification zone, the THg concentration ranged from 0.37 ng·L-1 to 85.69 ng·L-1[average concentration of (6.76±2.29) ng·L-1] and the MeHg concentration ranged from 0.04 ng·L-1 to 1.47 ng·L-1[average concentration of (0.35±0.17) ng·L-1]. The interference of human activities on mercury concentration is prominent. The vertical distribution of THg in the water is consistent with that of MeHg, the surface layer has lower values than the deep layer. Material balance suggested that THg in the wetland system decreases by 155.50 g per year, and MeHg decreases by 1.65 g per year, which has a protective effect on the downstream water.

[Distribution Characteristics of Mercury in Different Urban Constructed Wetlands].

To explore the spatial and temporal distribution and the methylation characteristics of mercury in different constructed wetlands in cities, and to understand the potential ecological exposure of mercury in urban wetlands, four artificial wetlands in Chongqing were studied from March 2017 to March 2018. The water samples were collected separately in four quarters, and the mass concentration of total mercury (THg) and methyl mercury (MeHg) was researched for one year. The results showed that the THg concentration in the four wetland waters is higher than the background value of the world's lakes and reservoirs for dam construction, but it is far lower than the waters with pollution history. The THg mass concentration of the water inside the wetlands is slightly higher than in the inlet and outlet. In addition, the THg mass concentration in the aquatic plant growing area, the construction area, the cruise ship parking area, and the frequent play area has an increasing trend, indicating that urban wetlands have a trapping and converging effect of the water's THg, so human activities influence total mercury a lot. The mass concentration of MeHg in the four wetland waters was slightly higher than that in other water bodies. With the exception of the Caiyun Lake, where the mass concentration of MeHg at the outlet was higher than that of the water inlet, the other three wetlands showed lower MeHg mass concentration in the outlet than the inlet. The mass concentration of MeHg in the wetland water increased with increasing water depth. The ratio of MeHg concentration to THg mass concentration (MeHg/THg) was higher than in other waters, indicating that urban wetlands have effect on net mercury methylation from waters. The photoreduction of mercury and its absorption by aquatic plants can reduce the mercury load from urban wetlands to downstream watersheds. The THg mass concentration of the four urban wetland water bodies was high in the spring and autumn, with a slight decrease in the summer, and lowest in the winter. The mass concentration of MeHg was the lowest in winter, and in the other three seasons it was basically flat, about three times higher than in winter. This study clarifies the temporal and spatial distribution and methylation of mercury in urban wetlands. It explores the degree of disturbance of human activities on wetlands and the response characteristics, as well as the impact of wetland mercury on downstream watersheds. To avoid potential mercury exposure, measures need to be established for the construction of artificial wetlands.

Retrospective Clinical Study of Advanced Pancreatic Cancer Treated With Chemotherapy and Abdominal Hyperthermia.

PURPOSE: Hyperthermia is a mechanistically plausible partner with chemotherapy, although many of the underlying molecular mechanisms of this combination treatment are not yet properly understood. Preclinical studies suggest that there is potential synergy with gemcitabine and that provides the basis for retrospective analysis of a clinical series combining these treatment modalities for patients with advanced pancreatic cancer. PATIENTS AND METHODS: Twenty-nine chemotherapy-naive patients with locally advanced or metastatic pancreatic carcinoma with malignant ascites were treated with intraperitoneal cisplatin 30 mg/m2 and gemcitabine 800 to 1,000 mg/m2 intravenously on days 1, 8, and 15 every 28 days until tumor progression. Patients also received regional hyperthermia treatment (41 to 42°C) on the upper abdomen two times per week from days 1 to 21. RESULTS: In all, 83 cycles of chemotherapy were administered and were generally well tolerated. No patients had a complete response, 13 had a partial response, seven had stable disease, and 9 had progressive disease. Mean progression-free survival and overall survival were 119 ± 61days and 195 ± 98 days, respectively. CONCLUSION: This study provides preliminary evidence that the treatment approach of combined systemic and intraperitoneal chemotherapy plus hyperthermia is well tolerated, is active, and has an acceptable survival profile for patients with stage IV pancreatic cancer and ascites.

[Hair Mercury Concentrations in Residents of Fuling and Zhongxian in the Three Gorges Reservoir Region and Their Influence Factors].

To evaluate the mercury (Hg) exposure risk for residents of the Three Gorges Reservoir Region (TGRR), hair samples were collected from 238 local residents within the central regions of the TGRR (Fuling District and Zhongxian County) in this study. Subsequently, total mercury (THg) and methylmercury (MeHg) concentrations were determined. The results obtained showed that the average THg and MeHg concentrations in hair samples of the residents within these two areas were (0.50±0.54) µg·g-1 and(0.35±0.25) µg·g-1, respectively. Specifically, the average THg and MeHg concentrations in hair samples of Fuling residents were(0.71±0.87) µg·g-1 and(0.53±0.46) µg·g-1, respectively. Both these values were higher than those in hair samples of Zhongxian County residents [THg(0.41±0.36) µg·g-1 and MeHg (0.28±0.26) µg·g-1]. It is noteworthy that the hair Hg levels in residents of these two areas are both well below the U.S. Environmental Protection Agency's reference dose (1 µg·g-1). Hair Hg levels varied slightly among different age groups; higher Hg levels were detected in residents in the age group of 40-50 years(P<0.05). However, there was no significant difference between the hair Hg levels among genders(P>0.05). Hair Hg levels in females were slightly above those in males. Hair Hg levels were significantly correlated with the frequency of fish consumption. Furthermore, hair Hg levels in non-fishermen were significantly lower than those in fishermen. An elevated mean value of (1.44±0.79) µg·g-1(P<0.01), which exceeds the RfD of 1 µg·g-1, was detected in fishermen. Moreover, hair Hg levels in smokers of Fuling and Zhongxian County[(0.55±0.24) µg·g-1 and (0.58±0.54) µg·g-1, respectively] were both markedly higher than those in non-smokers[(0.51±0.30) µg·g-1 and (0.36±0.26) µg·g-1respectively]. In conclusion, the risk of Hg exposure to residents of the TGRR was lower. However, in this study, it was determined that fishermen are at significant risk of Hg exposure.