R. B. Alexander R. A. Smith 1986 <p><span>The relationship between atmospheric SO</span>₂<span>&nbsp;emissions and stream and lake acidification has been difficult to quantify, largely because of the limitations of sulphur deposition measurements. Precipitation sulphate (SO</span>₄<span>) records are mostly &lt;5 yr in length</span>¹<span>&nbsp;and do not account for dry sulphur deposition</span>²<span>. Moreover, a variable fraction of wet- and dry-deposited sulphur is retained in soils and vegetation and does not contribute to the acidity of aquatic systems</span>^3,4<span>. We have compared annual SO</span>₂<span>&nbsp;emissions for the eastern United States from 1967 to 1980 with stream SO</span>₄<span>&nbsp;measurements from fifteen predominantly undeveloped watersheds (Figs 1,2). We find that the two forms of sulphur are strongly correlated on a regional basis and that streams in the southeastern United States (SE) receive a smaller fraction (on average, 16%, compared with 24% of regional sulphur emissions than do streams in the northeastern United States (NE). In addition to providing direct empirical evidence of a relationship between sulphur emissions and aquatic chemistry, these results suggest that there are significant regional differences in the fraction of deposited sulphur retained in basin soils and vegetation.</span></p> application/pdf 10.1038/322722a0 en Springer Nature Correlations between stream sulphate and regional SO2 emissions article