Black carbon concentrations, sources, and health risks at six cities in Mississippi, USA

Black carbon (BC) in ambient fine particulate matter (PM2.5) was measured for 15 months (Sept 2013–Dec 2014) at six locations throughout the state of Mississippi, USA, to investigate the distribution, temporal variations, potential sources, and health risks of BC. Sampling sites were divided into two groups based on population: large cities (Gulfport, Hattiesburg, and Jackson) and small cities (Grenada, Hernando, and Pascagoula). The mean concentration of BC was higher in large cities compared to small (mean ranges of 1.55 to 2.04 µg m−3 in large cities and 1.01 to 1.73 µg m−3 in small cities) and across locations BC was impacted by season and meteorological variables, particularly wind and precipitation. The results of potential source contribution function (PSCF) and concentration weighted trajectory (CWT) and trajectory cluster analysis confirmed that the long-range transport impacted BC concentration and air masses from the north-west were a major distant source of BC at all study sites. Read more about JPB Fellow Courtney Roper’s research.