Studies on pulmonary anthracosis. With special reference to the mineral constitution of intrapulmonary particulate pollutants in the human lung

In order to investigate anthracosis of the human lung, especially its causal relationship with atmospheric pollution and the occurrence of lung cancer, intrapulmonary particulate pollutants (IPP) from autopsy cases and patients lobectomized because of lung cancer were separated by alkali digestion of the lung tissue, and their elemental constitution was analyzed by a wavelength-dispersive X-ray fluorescence spectrometer. Silicon was the most abundant mineral constituent of non-carbonaceous fraction of IPP, followed by calcium, magnesium, iron, aluminum and other trace elements. The levels of silicon and aluminum in IPP were significantly higher in individuals treated at Saitama Medical School Hospital than in those from Tokyo. Farmers showed higher levels of silicon and aluminum than other occupational categories, whereas male blue-collar workers showed higher levels of calcium and lead than farmers. The level of iron in IPP of male smokers tended to be higher than in non-smokers. In cases of lung cancer, especially of the hilar type, the levels of iron, calcium, copper, lead, chromium and nickel in IPP tended to be higher than in non-lung cancer cases, whereas the levels of silicon and aluminum were lower than in non-lung cancer cases. On the basis of these results, pulmonary anthracosis was considered to be etiologically related to the occurrence of lung cancer.