Characteristics of Fine Particles in an Urban Atmosphere-Relationships with Meteorological Parameters and Trace Gases.

Tianhao Zhang,Hao Xiang,Wei Gong,Zhongmin Zhu,Ruimin Fang

doi:10.3390/ijerph13080807

Abstract

Atmospheric fine particles (diameter < 1 μm) attract a growing global health concern and have increased in urban areas that have a strong link to nucleation, traffic emissions, and industrial emissions. To reveal the characteristics of fine particles in an industrial city of a developing country, two-year measurements of particle number size distribution (15.1 nm–661 nm), meteorological parameters, and trace gases were made in the city of Wuhan located in central China from June 2012 to May 2014. The annual average particle number concentrations in the nucleation mode (15.1 nm–30 nm), Aitken mode (30 nm–100 nm), and accumulation mode (100 nm–661 nm) reached 4923 cm−3, 12193 cm−3 and 4801 cm−3, respectively. Based on Pearson coefficients between particle number concentrations and meteorological parameters, precipitation and temperature both had significantly negative relationships with particle number concentrations, whereas atmospheric pressure was positively correlated with the particle number concentrations. The diurnal variation of number concentration in nucleation mode particles correlated closely with photochemical processes in all four seasons. At the same time, distinct growth of particles from nucleation mode to Aitken mode was only found in spring, summer, and autumn. The two peaks of Aitken mode and accumulation mode particles in morning and evening corresponded obviously to traffic exhaust emissions peaks. A phenomenon of “repeated, short-lived” nucleation events have been created to explain the durability of high particle concentrations, which was instigated by exogenous pollutants, during winter in a case analysis of Wuhan. Measurements of hourly trace gases and segmental meteorological factors were applied as proxies for complex chemical reactions and dense industrial activities. The results of this study offer reasonable estimations of particle impacts and provide references for emissions control strategies in industrial cities of developing countries.

Highlights

Atmospheric aerosol particles greatly influence the global radiation budget and climate change by their associated radiative effects [1,2,3,4], and demonstrate an association with respiratory and cardiovascular morbidity and mortality through a series of toxicological and epidemiological studies [5,6,7,8,9]
The results that number concentrations of submicron particles in the size ranges of 15–30 nm, 30–100 nm, and 100–661 nm reached 4923 cm3, 12,193 cm3 and 4801 cm3, respectively, are evidence that central China has been suffering severe atmospheric fine particle contamination
There is scant published literature about fine particle concentrations in industrial regions of developing countries, it is of vital importance to reveal such characteristics in

Summary

Introduction

Atmospheric aerosol particles greatly influence the global radiation budget and climate change by their associated radiative effects [1,2,3,4], and demonstrate an association with respiratory and cardiovascular morbidity and mortality through a series of toxicological and epidemiological studies [5,6,7,8,9]. Existing standards for air quality, such as particulate matter with diameter smaller than 10 μm (PM10 ) and particulate matter with diameter smaller than 2.5 μm (PM2.5 ), are formulated. Res. Public Health 2016, 13, 807; doi:10.3390/ijerph13080807 www.mdpi.com/journal/ijerph

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Conclusion