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Air pollutant concentrations

About: Air pollutant concentrations is a research topic. Over the lifetime, 1652 publications have been published within this topic receiving 36138 citations.


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TL;DR: In this paper, the rescaled range (R / S ) analysis was used for analyzing the statistical persistence of air pollutants in Mexico City, and the results showed that long-range persistence is not a uniform property over a wide range of time scales, from days to months.
Abstract: The rescaled range ( R / S ) analysis was used for analyzing the statistical persistence of air pollutants in Mexico City. The air-pollution time series consisted of hourly observations of ozone, nitrogen dioxide, sulfur dioxide and particulate matter obtained at the Mexico City downtown monitoring station during 1999–2014. The results showed that long-range persistence is not a uniform property over a wide range of time scales, from days to months. In fact, although the air pollutant concentrations exhibit an average persistent behavior, environmental (e.g., daily and yearly) and socio-economic (e.g., daily and weekly) cycles are reflected in the dependence of the persistence strength as quantified in terms of the Hurst exponent. It was also found that the Hurst exponent exhibits time variations, with the ozone and nitrate oxide concentrations presenting some regularity, such as annual cycles. The persistence dynamics of the pollutant concentrations increased during the rainy season and decreased during the dry season. The time and scale dependences of the persistence properties provide some insights in the mechanisms involved in the internal dynamics of the Mexico City atmosphere for accumulating and dissipating dangerous air pollutants. While in the short-term individual pollutants dynamics seems to be governed by specific mechanisms, in the long-term (for monthly and higher scales) meteorological and seasonal mechanisms involved in atmospheric recirculation seem to dominate the dynamics of all air pollutant concentrations.

33 citations

Journal ArticleDOI
TL;DR: It is evidenced that ambient air pollutants have some effect on congenital malformation, amid the several tested combinations of air pollutant concentrations.

33 citations

Journal ArticleDOI
TL;DR: This work characterized distributions of emissions and concentrations of a few important urban air toxics at high spatiotemporal resolution in order to assess exposure and inequality, and suggested that disparities in exposure depend on pollutant type.

33 citations

Journal ArticleDOI
TL;DR: In this article, a grid-based numerical air pollution model for estimating air pollutant concentrations in an urban area is developed based on the continuity equation, which incorporates the combined influences of advective transport, turbulent diffusion, chemical transformation, source emissions and surface removal of air contaminants.

33 citations

Journal ArticleDOI
TL;DR: Asthma and dry cough were significantly higher among urban schoolchildren, and secondhand smoke, mold and the presence of new furniture at home were also linked to asthma symptoms.
Abstract: Rapid increases in traffic volumes in countries such as Malaysia may lead to exposure to poor air quality both outdoors and indoors. This study investigated asthma symptoms among Malaysian schoolchildren in relation to indoor and outdoor air pollution in urban and semi-rural settings in a school-based cross-sectional study of 1,952 schoolchildren living in urban and semi-rural areas. Parents completed a questionnaire including questions on asthma symptoms and environmental risk factors. Air pollutant concentrations were measured at 16 schools. Analysis used multiple logistic regression controlling for sociodemographic and indoor air pollution factors. A total of 11.4, 7.6, 9.5 and 7.0 % schoolchildren had asthma, current wheeze, dry cough at night and wheezing after exercise, respectively. Asthma and dry cough were significantly higher among urban schoolchildren. A 10-μg/m3 increase in outdoor NO2 level was associated with a twofold increase in the reporting of current wheeze (odds ratio (OR) 1.90; 95 % confidence interval (CI) 1.02–3.52); a 10-μg/m3 increase in indoor PM2.5 was similarly associated with a twofold increase in the reporting of wheeze during exercise (OR 2.08; 95 % CI 1.02–4.26). Secondhand smoke (SHS), mold and the presence of new furniture at home were also linked to asthma symptoms. NO2 concentrations in urban Malaysia frequently exceed those of the international standards. Exposure to traffic-related air pollution may be linked to asthma symptoms among children in Malaysia.

32 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202316
20229
2021100
202084
201972
201852