Health impacts of domestic coal use in China

Abstract

Domestic coal combustion has had profound adverse effects on the health of millions of people worldwide. In China alone several hundred million people commonly burn raw coal in unvented stoves that permeate their homes with high levels of toxic metals and organic compounds. At least 3,000 people in Guizhou Province in southwest China are suffering from severe arsenic poisoning. The primary source of the arsenic appears to be consumption of chili peppers dried over fires fueled with high-arsenic coal. Coal samples in the region were found to contain up to 35,000 ppm arsenic. Chili peppers dried over high-arsenic coal fires adsorb 500 ppm arsenic on average. More than 10 million people in Guizhou Province and surrounding areas suffer from dental and skeletal fluorosis. The excess fluorine is caused by eating corn dried over burning briquettes made from high-fluorine coals and high-fluorine clay binders. Polycyclic aromatic hydrocarbons formed during coal combustion are believed to cause or contribute to the high incidence of esophageal and lung cancers in parts of China. Domestic coal combustion also has caused selenium poisoning and possibly mercury poisoning. Better knowledge of coal quality parameters may help to reduce some of these health problems. For example, information on concentrations and distributions of potentially toxic elements in coal may help delineate areas of a coal deposit to be avoided. Information on the modes of occurrence of these elements and the textural relations of the minerals and macerals in coal may help predict the behavior of the potentially toxic components during coal combustion.

Figure 1

Map of China indicating provinces in which there are reported health problems caused by domestic coal combustion.

Figure 2

Extensive scaly lesions (hyperkeratosis) are evident on the chest of a resident of this region. The dark spot over the left breast was diagnosed as Bowen’s disease.

Figure 3

(A) SEM back-scattered electron image of polished coal showing a pyrite grain (P) and adjacent arsenopyrite crystals (A). (B) SEM back-scattered electron image of polished coal showing the deposition of a banded complex of iron oxide and As-bearing iron phosphates. (C) SEM back-scattered electron image of polished block of arsenic-rich coal. Dark areas are coal, bright areas are mainly pyrite, milky area is coal containing organically bound arsenate. Fluids moving through the fracture in the coal appears to have removed arsenic from the organic matrix. (D) X-ray map depicting the distribution of arsenic in the coal. Red areas are high concentrations, and blue areas are low concentrations. Compare distribution of arsenic to the outline of the milky area in C. A–C originally appeared in ref. and are republished with the permission of the Pittsburgh Coal Conference.

Figure 4

Bone deformation caused by nutritional deficiency combined with exposure to high levels of fluorine from domestic coal combustion.