AimsTo investigate the online activities, prevalence of Internet Addiction in relation to demographic characteristics and risk factors related to family and school among adolescents.MethodsA total of 6468 10–18 year old adolescents recruited from local schools in Guangzhou, China were selected by adopting multi-stage stratified random sampling (female/male: 2886/3582; mean age:13.78 ± 2.43). Participants completed a structured questionnaire.ResultsThe overall prevalence of Internet Addiction was 26.50%, with severe addiction being 0.96%. Internet Addiction was higher among males than females (30.6% versus 21.2%). Older grade students reported more Internet addiction rate (χ2 = 431.25, P < 0.001). The five highest-ranked online activities were social networking (94.73%), school work (86.53%), entertainment (82.44%), Internet gaming (73.42%) and shopping online (33.67%). A negative relationship with teachers (OR: 1.35, 95% CI: 1.20–1.53), a negative relationship between two parents (OR: 1.23, 95% CI: 1.18–1.37), and poor academic performance (OR: 1.22, 95% CI: 1.17–1.35), showed the highest relative risks for Internet addiction.ConclusionsSevere Internet Addiction is not common, but mild Internet addiction was reported by more than one fourth of all participants. The rates of Internet Addiction varied by gender, grade, the quality of family relationships and school situation, suggesting these factors should be considered when designing and implementing interventions.
Abstract. The Sichuan Basin (SCB) is one of the regions suffering from severe air
pollution in China, but fewer studies have been conducted for this region
than for the more developed regions in eastern and northern China. In this study,
a source-oriented version of the Community Multiscale Air Quality (CMAQ)
model was used to quantify contributions from nine regions to PM2.5
(i.e., particulate matter, PM, with an aerodynamic diameter less than 2.5 µm) and its components in the 18 cities within the SCB in the winter
(December 2014 to February 2015) and summer (June to August 2015). In the
winter, citywide average PM2.5 concentrations are 45–126 µg m−3, with 21 %–51 % and
39 %–66 % being
due to local and nonlocal emissions, respectively. In the summer,
15 %–45 % and 25 %–52 % of citywide average
PM2.5 (14–31 µg m−3) are due to local and
nonlocal emissions, respectively. Compared to primary PM (PPM), the
inter-region transport of secondary inorganic aerosols (SIA), including
ammonia, nitrate, and sulfate ions (NH4+, NO3-, and
SO42-, respectively), and their gas-phase precursors are greater.
The region to the east of SCB (R7, including central and eastern China
and others) is the largest contributor outside the SCB, and it can
contribute approximately 80 % of PM2.5 in the eastern, northeastern,
and southeastern rims of the SCB but only 10 % in other SCB regions in
both seasons. Under favorable transport conditions, regional transport of
air pollutants from R7 could account for up to 35–100 µg m−3 of PM2.5 in each of the SCB cities in the winter. This
study demonstrates that it is important to have joint emission control
efforts among cities within the SCB and regions to the east in order to
reduce PM2.5 concentrations and prevent high PM2.5 days for the
entire basin.
The Sichuan Basin (SCB) is located in southwestern China and has a total population of 108.1 million across 18 cities, including the 2 largest in western China (Chengdu and Chongqing). As most air quality monitoring stations are located in urban areas, we simulated the PM 2.5 (i.e., particulate matter with an aerodynamic diameter < 2.5 µm) and ozone (O 3 ) in the entire SCB during winter (December 2014-February 2015) and summer (June-August 2015) by using the Weather Research and Forecasting (WRF) and the Community Multi-scale Air Quality (CMAQ) models. The simulated concentrations of 24-h PM 2.5 and its major components generally agree with observations during both seasons, but the simulated 1-h and 8-h O 3 are acceptable only for summer. Increasing in severity from the rim of the SCB to its inner areas, the PM 2.5 , as well as its major components, exhibits hotspots near the central urban areas of Chongqing and Chengdu, with concentrations of 150-200 µg m -3 and 40-60 µg m -3 during winter and summer, respectively. The 1-h and 8-h O 3 exhibit no hotspots in the urban centers of Chongqing and Chengdu but show elevated levels in some rural and suburban areas (55-70 ppb and 65-80 ppb, respectively), including those on the western and southwestern rim of the SCB, and downwind of the urban center of Chongqing. Despite the great spatial variations in the PM 2.5 and O 3 concentrations, the vast majority of the basin fails to meet the WHO guidelines for 24-h PM 2.5 (25 µg m -3 ) and 8-h O 3 (~47 ppb) on > 70% of the days during winter and > 40% of the days during summer, respectively. Based on the aforementioned spatial patterns of the PM 2.5 and O 3 concentrations, and the wind directions within the basin, strictly controlling emissions originating in the SCB may greatly reduce PM 2.5 and O 3 concentrations within the basin.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.