Carbon isotopes and sulphur contents as indicators of atmospheric pollution from burning fossil fuels

This paper summarized the study carried out in Krakow, Poland in 1975-76 on the estimated local air pollution as measured by carbon isotopes and total sulphur measurement in plants. Good correlation was found between δ¹⁴C value and the total sulphur (measured by radionuclide excited X-ray fluorescence) in beech leaves collected in the late summer, indicating the common source of both pollutants. Sampling and measurement of σ¹³C in atmospheric CO₂ has shown that σ³C can be used as a pollution indicator only in the winter period when no fluctuations exist ddue to plant respiration. A method of CO₂ sampling using molecular sieve proved to be feasible for instantaneous sampling with no isotope fractionation. The highest pollution by fossil CO₂ was measured in winter (12.8% excess. During spring and summer the average contribution of fossil CO₂ was 4.5 to 5.6%.