scholarly journals The Effects of Socioeconomic and Environmental Factors on the Incidence of Dengue Fever in the Pearl River Delta, China, 2013

2015 ◽  
Vol 9 (10) ◽  
pp. e0004159 ◽  
Author(s):  
Xiaopeng Qi ◽  
Yong Wang ◽  
Yue Li ◽  
Yujie Meng ◽  
Qianqian Chen ◽  
...  
Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 749
Author(s):  
Yuan Gao ◽  
Zini Lai ◽  
Chao Wang ◽  
Haiyan Li ◽  
Yongzhan Mai

Water pollution can be monitored through the use of indicator species, including Brachionus calyciflorus. To do this, it is necessary to understand the species’ population ecology. Four surveys of zooplankton were conducted in May, August, and December 2018 and February 2019 in the Pearl River Delta, China, to examine the population characteristics of B. calyciflorus. The temporal and spatial distribution of abundance, biomass, dominance, and occurrence frequency were compared with those from 2012 to investigate the relationship between changes in the population of B. calyciflorus and environmental factors. The average abundance, dominance, and occurrence of B. calyciflorus in this survey were significantly higher than those of 2012 in all seasons. Principal component analysis showed that environmental factors such as the temperature, transparency, total nitrogen, and total phosphorus of water had a major impact on the abundance of B. calyciflorus. There was a significant positive correlation with transparency, total nitrogen, and total phosphorus of water, and a very significant positive correlation with water temperature. Overall, these results demonstrated that the distribution characteristics of B. calyciflorus can reflect pollution in water bodies and can be used to evaluate water quality. These research results provide a reference for evaluating China’s river health and can help to manage water quality in the Pearl River Delta.


2021 ◽  
Vol 15 (9) ◽  
pp. e0009776
Author(s):  
Chuanxi Li ◽  
Qi Zhao ◽  
Zhe Zhao ◽  
Qiyong Liu ◽  
Wei Ma

Background Studies have shown that tropical cyclones are associated with several infectious diseases, while very few evidence has demonstrated the relationship between tropical cyclones and dengue fever. This study aimed to examine the potential impact of tropical cyclones on dengue fever incidence in the Pearl River Delta, China. Methods Data on daily dengue fever incidence, occurrence of tropical cyclones and meteorological factors were collected between June and October, 2013–2018 from nine cities in the Pearl River Delta. Multicollinearity of meteorological variables was examined via Spearman correlation, variables with strong correlation (r>0.7) were not included in the model simultaneously. A time-stratified case-crossover design combined with conditional Poisson regression model was performed to evaluate the association between tropical cyclones and dengue fever incidence. Stratified analyses were performed by intensity grades of tropical cyclones (tropical storm and typhoon), sex (male and female) and age-groups (<18, 18–59, ≥60 years). Results During the study period, 20 tropical cyclones occurred and 47,784 dengue fever cases were reported. Tropical cyclones were associated with an increased risk of dengue fever in the Pearl River Delta region, with the largest relative risk of 1.62 with the 95% confidence interval (1.45–1.80) occurring on the lag 5 day. The strength of association was greater and lasted longer for typhoon than for tropical storm. There was no difference in effect estimates between males and females. However, individuals aged over 60 years were more vulnerable than others. Conclusions Tropical cyclones are associated with increased risk of local dengue fever incidence in south China, with the elderly more vulnerable than other population subgroups. Health protective strategies should be developed to reduce the potential risk of dengue epidemic after tropical cyclones.


2010 ◽  
Vol 29 (6) ◽  
pp. 35-42
Author(s):  
Jianhua WANG ◽  
Linglong CAO ◽  
Xiaojing WANG ◽  
Xiaoqiang YANG ◽  
Jie YANG ◽  
...  

Wetlands ◽  
2021 ◽  
Vol 41 (4) ◽  
Author(s):  
Xiao-Shan Fang ◽  
Shuang Liu ◽  
Wei-Zhi Chen ◽  
Ren-Zhi Wu

AbstractThe Guangdong Xinhui National Wetland Park (GXNWP) in the Pearl River Delta is an important stopover for migratory birds in China and East Asia. Due to high levels of interference, high sensitivity and fragile environmental constraints, an efficient method to assess the health status of wetland parks such as the GXNWP is urgently needed for sustainable development. In this study, we proposed a habitat-landscape-service (HLS) conceptual model that can be used at the site scale to evaluate health status in terms of habitats, landscapes and services by considering the complex ecosystem of wetland parks. This HLS model included 28 evaluation indicators, and the indicator weights and health-grade divisions were based on expert scores using both the analytic hierarchy process (AHP) and fuzzy comprehension evaluation (FCE) methods. The results showed that the health status of the GXNWP was at the “subhealthy” level, with a membership function of 0.4643. This study found that habitat indicators (0.5715) were the key factors affecting the GXNWP health status, followed by service indicators (0.2856) and landscape indicators (0.1429). The HLS-AHP-FCE method provides a holistic health evaluation indicator system and diagnostic approach for rapidly developing wetland parks in the Pearl River Delta, China.


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