diseases of the respiratory system was the leading cause of morbidity increasing from cases per population in to cases per population in detailed data are not available on the characterization of diseases such as asthma allergy and asbestosis with respiratory disease origin the leading five causes of cancer in males were cancers of the liver per cent stomach per cent lung per cent oesophagus per cent and pancreas per cent whereas cancers of the liver per cent cervix per cent stomach percent breast per cent oesophagus per cent and ovary per cent were the main causes for women for example air pollution from indoor burning of coal or biomass w as associated w ith substantial increase of lung cancer risk