Characteristics of Individual Particles Emitted from an Experimental Burning Chamber with Coal from the Lung Cancer Area of Xuanwei, China

Wenhua Wang,Jie Li,Daizhou Zhang,Chenchong Zhang,Jingkun Jiang,Lingli Chang,Longyi Shao

doi:10.4209/aaqr.2018.05.0187

Abstract

ABSTRACT Pollutants emitted from household coal burning in Xuanwei, China, have been recognized as the reason for the high lung cancer mortality and morbidity rates in the area. To examine the characteristics of particles emitted from coal burning, a coal burning-dilution chamber was designed, and the individual particles emitted from the chamber at different burning stages were collected. The morphologies and elemental compositions of the individual particles were analyzed by high resolution transmission electron microscopy. Four types of particles, namely, organic particles, soot particles, S-rich particles, and mineral particles, were identified. The largest percentage of particles by number in the ignition stage, fierce-burning stage, and char-burning stage was composed of organic particles (66%), soot particles (71%), and mineral particles (73%), respectively. A distinctive characteristic was the remarkable abundance of Si- and Fe-rich particles during the char burning stage, compared with emissions from other types of coal. According to the elemental composition, 49% of the mineral particles were Si-rich, 25% were Ca-rich, 14% were Fe-rich, and 7% were Ti-rich. The Si-rich particles were partly identified as quartz (SiO2), the Ca-rich particles were found to be CaSO4 or CaCO3, the Fe-rich particles were primarily Fe2O3 or Fe3O4, and the Ti-rich particles were mainly TiO2. Notably, SiO2 is a human carcinogen, and Fe-rich particles possess a high reactive potential with DNA-markers.

Highlights

China both produced and consumed a large amount of coal every year
Pollutants emitted from household coal burning in Xuanwei, China, have been recognized as the reason for the high lung cancer mortality and morbidity rates in the area
To examine the characteristics of particles emitted from coal burning, a coal burning-dilution chamber was designed, and the individual particles emitted from the chamber at different burning stages were collected

Summary

Introduction

China both produced and consumed a large amount of coal every year. In 2016, about 2.6 billion tons of coal were consumed in China, which accounted for 62.0% of national primary energy source (National Bureau of Statistics of the People’s Republic of China; http://www.stats.gov.cn/tjsj/ndsj/). Industrial coal combustion shows relative low emission factors of particulate matter (PM) by installing air pollution control devices (Zhou et al, 2016). Household coal burning for cooking and heating in Chinese rural areas is popular (Zhu et al, 2012; Zhang et al, 2014; Cai et al, 2018), which causes high indoor PM pollution (Hu et al, 2014), especially in wintertime (Li et al, 2017). Household coal burning can cause human health problems in some rural areas and has attracted attention in recent years (Chen et al, 2015; Tiwari et al, 2015; Li et al, 2017; Lui et al, 2017; Finkelman and Tian, 2018)

Methods

Results

Conclusion