[Structural Characteristics of Phytoplankton Communities and Its Relationship with Environmental Factors in a Group of Drinking Water Reservoirs by Water Transmission from Modaomen Waterway in Zhuhai].

Modaomen Waterway is the main outlet of the Pear River system and an important water source for Zhuhai and Macao. The water quality of 13 sampling sites in Modaomen Waterway, phytoplankton, and environmental factors were investigated at 21 sampling sites in 4 drinking water source groups, which transport water from Modaomen Waterway and connect with each other, in August and October of 2021. A total of 73 genera of phytoplankton in eight phyla were identified, with a total of 150 species, most of them belonging to Cyanophyta, Chlorophyta, and Bacillariophyta. The relative abundance of Cyanophyta was higher than 90% in the DJS and YL reservoirs during flood and dry seasons; Cyanophyta, Chlorophyta, and Bacillariophyta were dominant phyla during different seasons; and their distribution was balanced in the ZXD and ZY reservoirs. The Shannon-Wiener index, Pielous uniformity index, and Margalef richness index showed that the ZY reservoir had the most abundant biodiversity, which indicated the best water quality, followed by the ZXD and YL reservoirs. Conversely, the DJS was the least diverse reservoir for phytoplankton. The PCoA analysis indicated significant differences in plankton structures in ZXD and ZY with the other two reservoirs (P<0.05), respectively. Redundancy analysis (RDA) showed that the main environmental factors affecting the distribution of the phytoplankton community were NO3-, TOC, TP, Cl-, and NH4+-N. These results indicated that the phytoplankton community of the four reservoirs were greatly affected by the nutrient salt caused by water transport, which suggested that the water quality of Modaomen Waterway should be improved to increase reservoir water nutrition to ensure the safety of drinking water sources.

[Pollution Characteristics and Risks of Polycyclic Aromatic Hydrocarbons in Underground and Surface Drinking Water Sources in Northeast Inner Mongolia].

Polycyclic aromatic hydrocarbons (PAHs) are hazardous and ubiquitous pollutants in the aquatic environment, and understanding the pollution characteristics and risk levels of PAHs is of great significance to the sustainable development of drinking water sources and drinking water safety. Hence, PAHs residues were measured qualitatively and quantitatively with solid-phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS) in 33 water samples (including 22 groundwater and 11 surface water samples) of the drinking water sources in the Manzhouli and Xinyouqi areas of northeast Inner Mongolia, and assessments of the pollution level of PAHs and the health and ecological risks were carried out. The results showed that PAHs were detected in all 33 sampling points of Manzhouli drinking water sources, except for benzo[k] fluoranthene, benzo[a] pyrene, and dibenzo[a,h] anthracene, with detection rates ranging from 36.36% to 95.45%; the detection rates of the other 13 PAHs monomers were 100%. The detection range of ρ（ΣPAHs） was 42.76-164.50 ng·L-1, and the mean value was 90.82 ng·L-1. The detection ranges of ρ（ΣPAHs） in surface water and groundwater were 66.39-164.50 ng·L-1 and 42.76-147.70 ng·L-1, respectively. The concentration of the detected naphthalene was the highest, with a mean value of 36.91 ng·L-1, and the concentration of anthracene was the lowest, with a mean value of 0.81 ng·L-1; there were no significant differences among the concentrations of all the PAHs monomers of the surface and groundwater (P>0.05). The pollution of PAHs was at a median level in China and abroad, mainly in the middle and low loops (3-4 loops). The analysis of the sources of PAHs in groundwater and surface water in Manzhouli using the ratio feature method and principal component analysis showed that the PAHs in the drinking water source water bodies in the Manzhouli area were mainly affected by the combustion of coal and biomass and oil, and some surface water sources were affected by the oil source. The human health and ecological risk assessment results showed that the water body of drinking water would not cause health risks to the human body, and the ecological risk was at a medium level; however, the high risk of benzo[b] fluoranthene (BbF) monomer production should be continuous cause for concern. From the perspective of the sustainable development of drinking water sources and drinking water safety, the necessary supervision and protection measures should be considered to prevent further pollution. The results of this research provide a scientific basis for the pollution control and prevention and control of PAHs in drinking water sources.

Clinical characteristics and advantages of primary peripheral micro-sized lung adenocarcinoma over small-sized lung adenocarcinoma.

OBJECTIVES: Micro-sized lung adenocarcinoma with a tumour of 1.0 cm or less could help identify the patients who would undergo the surgery treatment with limited resection; however, its clinical characteristics and survival rates remain unclear and are to be tested further. METHODS: Histology, lymphatic metastasis, surgical procedure and survival rates of 366 lung adenocarcinoma patients (from January 2007 to December 2013) with a tumour of 2.0 cm or less were analysed retrospectively. Among these patients, 175 had a primary tumour with a diameter of 1.0 cm or less and 191 had a tumour of 1.1-2.0 cm. The survival of 366 patients was evaluated by the restricted mean survival time (RMST) test, and the risk factors were assessed by multivariable analysis. RESULTS: Larger lesion had a significant relation to old age, male sex, preoperatively carcinoembryonic antigen (CEA) positive, invasive adenocarcinoma (IAC) and advanced-stage disease (P < 0.0001, P = 0.001, P = 0.001, P < 0.0001 and P < 0.0001, respectively). Patients with adenocarcinoma in situ (AIS)/minimally invasive adenocarcinoma obtained a better prognosis than those with IAC (5-year overall survival rate: 98.5 vs 84.3%, P = 0.001; disease-related survival rate: 98.5 versus 85.2%, P = 0.001). The 5-year overall survival rates of patients with a tumour less than 1.0 cm in comparison with 1.1-2.0 cm were 100.0 and 88.4% (P < 0.001), whereas the 5-year lung adenocarcinoma-specific survival rates were 100.0 and 89.0% (P < 0.001), respectively. Multivariable analysis for prognosis of lung adenocarcinoma patients with a tumour 2.0 cm or less in diameter revealed that histology, lymphatic metastasis and advanced pathological stage affected the 5-year overall and disease-related survival rates unfavourably (P < 0.0001, 0.002, 0.001; and P < 0.0001, 0.005, 0.001, respectively), whereas tumour size did not have an obvious influence on survival. CONCLUSIONS: Micro-sized lung adenocarcinoma (1.0 cm or less) had specific clinical characteristics and more favourable survival rates. These tumours and a subtype of AIS evaluated by computed tomography images or intraoperative frozen section may be appropriate candidates for a limited resection without mediastinal lymph node dissection.

[Distribution Characteristics and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Water of Yuqiao Reservoir Watershed During the Water Delivery Period].

In order to understand the pollution status of polycyclic aromatic hydrocarbons (PAHs) in the groundwater of Yuqiao Reservoir Watershed, the 16 US EPA priority control PAHs in the groundwater of this region were analyzed by gas chromatography-mass spectrometry. Not only the distribution characteristics and sources of PAHs, but also the potential probabilistic carcinogenic risk through drinking water and the ecological risk were assessed in this study. The results showed that PAHs could be detected in all the 18 samples. The results showed that the contents and concentration of PAHs were different between the upstream river and Yuqiao Reservoir. For the upstream river, the concentrations of ∑PAHs ranged from 13.7 ng·L-1 to 104.1 ng·L-1, and the low-ring number PAHs was dominant except the site of Sahe river bridge, and 2-3 ring number PAHs accounted for about 86%-95% of the ∑PAHs. The heavier contaminant level was monitored among the intensive fishery breeding areas located in Dahei river reservoir. For the Yuqiao Reservoir, the mass of 2-3 ring and 4-6 ring number PAHs was similar and the concentration of ∑PAHs ranged from 1.6 ng·L-1 to 3512.5 ng·L-1. The highest ∑PAHs was measured at the sampling sites located in the north of reservoir. The resource pollution of PAHs in this region was appointed by the molecular ratio of Flu/Pyr and Fla/(Fla+Pyr) and it showed that the combustion of coal and biomass was predominant during the sampling campaign. The health risk of drinking water in the study area was evaluated using the recommended method by US EPA and the cancer risk exceeded 10-6. The ecological risk was assessed by the value of risk quotient (RQ) adopted by Kalf and the RQs of B[a]A, B[k]F and BaP were all higher than 1. The above results indicated that the government should pay enough attention to the health risk and ecological risk of PAHs in the water of reservoir.