The permanence of paper is affected by many external and internal fact
ors. Anthropogenic air pollutants such as sulphur dioxide (SO2), nitro
gen oxides (NOx) or hydrogen chloride (HCl) belong to the category of
external forces. In comprehensive tests the ageing of paper, affected
by these air pollutants, was investigated based on woodfree and wood-c
ontaining papers as well as handsheets of different composition. Mecha
nical, optical and chemical properties of the artificially aged papers
were analysed to assess the effects on paper degradation. In Part I o
f this publication series the influence of air pollutants on the perma
nce of various graphic papers is dealt with.