Stable carbon isotope reveals high impact of fishing ship activities on total carbon from PM in Qingdao, China.

Although total carbon (TC) is an important component of fine particulate matter (PM: particulate matter with aerodynamic diameter of <2.5 μm); its sources remain partially unidentified, especially in coastal urban areas. With ongoing development of the global economy and maritime activities, ship-generated TC emissions in port areas cannot be neglected.