Analysing Temporal Trends in the Ratios of PM2.5/PM10 in the UK

Abstract

The size of atmospheric Particulate Matter (PM) is important as a determining factor for how long the particle stays in the atmosphere, and where it deposits in the human respiratory tract. Therefore, it is important to analyse PM 2.5 /PM 10 ratios as an indicator of the fine particles and determine how the ratios vary both in space and time. This study uses the most recent 5 years (2010-2014) PM 2.5 and PM 10 data (µg m -3 ) from 46 monitoring stations, which are part of the UK Automatic Urban and Rural Network (AURN). In this paper mostly robust statistics, which are not sensitive to non-normal distributions and to extreme values in both tails of the distributions are applied to assess temporal trends in PM 2.5 , PM 10 and their ratios. PM 2.5 /PM 10 ratios demonstrated considerable temporal and spatial variability in the UK and 5 years median ranged from 0.4 to 0.8, resulting in overall median of 0.65. Theil-Sen temporal trend analysis showed that PM 2.5 /PM 10 ratios have increased at several monitoring sites in the UK despite the fact that both PM 2.5 and PM 10 levels have predominantly decreased. However, trend in PM 2.5 /PM 10 ratios averaged over the 46 monitoring sites was insignificant. Trends in the ratios of PM 2.5 /PM 10 varied during different seasons: spring showed positive significant trend and winter showed negative significant trend, whereas trends in autumn and summer were insignificant.

Dynamic Complex Network Analysis of PM<sub>2.5</sub> Concentrations in the UK using Hierarchical Directed Graphs (V1.0.0)

“…Causal inference between primary (emitted directly by the emission sources) and secondary (produced in the atmosphere by the transformation of gaseous pollutants) is challenging. For example, whilst combustion sources such as road traffic account for the bulk of anthropogenic PM emissions and cause PM2.5 formation (Munir, 2017;AQEG, 2012), meteorological conditions can also influence PM2.5 concentrations through dispersion, and deposition. Due to the high data complexity and dimensionality caused by the contribution of atmospheric chemistry transport processes and a range of emission sources in ambient PM2.5 concentrations, we need to overcome the high dimensionality challenge and compress the concentration data into 2-dimensional (2D) network.…”

Ongoing Conflict Makes Yemen Dark: From the Perspective of Nighttime Light

“…sensing images [51][52][53], especially in long time series of vegetation variation analysis [49,50,52]. The formula is as follows:…”

“…The Theil-Sen Median is a robust trend analysis method with non-parametric statistics [49] and is a particularly effective tool for estimating the trends in small series [49,50]. The Theil-Sen Median has been widely used to test the trend of time series remote sensing images [51][52][53], especially in long time series of vegetation variation analysis [49,50,52]. The formula is as follows:…”

Acerca de la estimación de la fracción PM2.5/PM10

“…En este contexto, según Munir en 2017, la fracción PM2.5/PM10 es un indicador de la presencia de partículas finas en el aire que contribuye al estudio del tamaño de las partículas [11]. Gomiscek, en el 2004, se apoyan en estudios epidemiológicos generales para afirmar que la fracción de partículas finas en el aire tiene un impacto considerable sobre la salud humana, incluso en concentraciones por debajo de los límites establecidos para PM2.5 en las normas internacionales [9].…”

“…343-348, December, 2017. diámetro aerodinámico menor que 2.5 µm. Es por esta razón que en este trabajo se prefiere hablar de la "fracción PM2.5/PM10", en lugar de hablar de la "razón PM2.5/PM10".De acuerdo con Munir en 2017, el tamaño de las partículas en el aire es un factor decisivo para determinar el tiempo que permanecen las partículas en la atmósfera, así como para determinar en qué partes del tracto respiratorio se podrían depositar [11]. En este contexto, según Munir en 2017, la fracción PM2.5/PM10 es un indicador de la presencia de partículas finas en el aire que contribuye al estudio del tamaño de las partículas [11].…”