BACKGROUND The air quality index (AQI) is widely used to characterize the quality of ambient air. Chinese cities officially report the AQI on a daily basis. To assess the possible effects of air pollution on daily outpatient visits, we examined the association between AQI and the daily outpatient count. METHODS Daily data on outpatient visits to each clinical department were collected from th...

A linear regression model of particle pollution and an ordered logistic regression model of the relevant index were selected for observations in the US city of Los Angeles, California. Models were used to forecast Air Quality Index (AQI) from a sample, and were compared and contrasted. Methods are comparable overall but markedly different in their powers to predict certain categories. Linear re...

The so-calledAir Quality Index (AQI), expresses the quality of atmospheric air. The overall AQI is determined from the AQIs of some reference air pollutants, which are calculated by a transform of the respective concentrations. Concentrations of air pollutants are compositional data; they are expressed as part of mass of each pollutant in a total air volume or mass. Therefore, air pollution con...

Air pollution indices are commonly used to indicate the level of severity of air pollution to the public. The Pollution Standards Index (PSI) was initially established in response to a dramatic increase in the number of people suffering respiratory irritation due to the deteriorating air quality. The PSI was subsequently revised and implemented by the USEPA in 1999, and became known as the Air ...

Outdoor air pollution is a serious problem in many developing countries today. This study focuses on monitoring the dynamic changes of air quality effectively in large cities by analyzing the spatiotemporal trends in geo-targeted social media messages with comprehensive big data filtering procedures. We introduce a new social media analytic framework to (1) investigate the relationship between ...

BACKGROUND In the study, the Aras Basin and its environment, one of the most important hydrological basins of Turkey, was evaluated. In survey area, to determine the change of air quality, it was benefited from 23,770 pieces of hourly measured SO2 (Sulfur dioxide) and PM10 (particulate matter) concentration values for the December, January and February of 2009-2010 in which the pollution is at ...

With the continuous progress of human production and life, air quality has become the focus of attention. In this paper, Beijing, Tianjin, Hebei, Shanxi, Shandong and Henan provinces were taken as the study area, where there are 58 air quality monitoring stations from which daily and monthly data are obtained. Firstly, the temporal characteristics of the air quality index (AQI) are explored. Th...

background: contemporary development of growing urban communities and increasing the economical and industrial activities in the current century without paying attention to assess the effect of these activities on human health, as the axis of the development, is caused urban air pollution and risks from different pollutant emissions. tehran air pollution has received considerable media coverage...