Source identification for non-volatile particulate matter by laser derivatization

According to the EPA, soot from diesel sources is responsible for more than 8,300 premature deaths, 360,000 asthma attacks, 23,000 cases of bronchitis, 10,000 hospital admissions and 1.5 million lost work days in the US per year [1]. Nearly 50% of all soot from aircraft is not released at ground level but in the upper troposphere. Though constituting only ∼ 1% by mass of jet engine emissions, the black carbon emission presents the largest aerosol surface area [2]. New findings show soot may be contributing to changes happening near the North Pole, such as accelerating melting of sea ice and snow and changing atmospheric temperatures [3]. Although black carbon is hydrophobic, chemical and physical changes occurring at its surface can create functional groups that attract and retain water, thereby causing it to become hydrophilic [4]. Such changes determine whether soot acts as cloud condensation nuclei, its susceptibility to washout and participation in atmospheric heterogeneous reactions, thereby significantly impacting the atmospheric radiative balance [5]. Recent estimates place black carbons' radiative forcing as ∼ 0.5 to 0.8 W/m², nearly 50% that of CO₂ [3].