Caution must be exercised in assessing the public heath burden due to exposure to radiation since some health problems, such as cancer, may also be caused by other factors. This topic includes statistics about morbidity (incidence and prevalence) due to toxic substance-related or radiation-related diseases and conditions, as well as measurement of the associated impact on the labour force and on the economic costs. Where available, the attributable fraction and burden of diseases, premature deaths and DALYs associated with toxic substances and radiation is to be included in this topic. These statistics are also relevant in Topic 4.2.2: Impact of technological disasters. The main provider of epidemiological data is usually a country’s sanitation or health authority.