Tracing polycyclic aromatic hydrocarbons in the environment using ¹³C/¹²C ratios

The origin of polycyclic aromatic hydrocarbons (PAH) input sources to the sediments of three study sites was elucidated using the isotopic composition and the molecular abundance of individual 3-, 4- and 5-ring PAH in two component mixing calculations. PAH inputs to the St. John's Harbour mainly consisted of a mixture of petroleum and combustion-derived sources with vehicular emissions being the most important combustion input source. Combustion-derived sources of PAH were also apparent in the Conception Bay sediments, however, the presence of a source possibly of petroleum or diagenetic origin was also evident in these sediments. PAH inputs to most sites along the International segment of the St. Lawrence River consisted of mixtures of combustion and petroleum-derived contributions. However, inputs to the Prescott-Ogdenburg sediment were mainly of petroleum origin while inputs to the Brockville sediments were from combustion-derived sources with evidence of strong local point sources dominating in this area.