Emission characteristics of PM2.5-bound chemicals from residential Chinese cooking

Abstract

The chemical composition of fine particulate matter (PM2.5) emitted during cooking such as polycyclic aromatic hydrocarbons (PAHs), chemical elements (especially heavy metals), organic carbon (OC), and elemental carbon (EC) are of great concern to human health in China. We collected five duplicate sets of samples of cooking emissions from a Chinese residential kitchen for the five most common cooking methods based on orthogonal design. Emission rates and concentrations of PM2.5-bound chemicals, including 16 PAHs, 21 elements, OC, and EC, were determined based on the corresponding mass fraction of species in PM2.5. The chemical profile of PM2.5 varied according to the cooking method. The results indicated that OC was the dominant component of the fine emitted particles and the emission rates ranged from 27.87 μg/min to 1916.68 μg/min. In comparison, the emission rates of EC ranged from 2.02 μg/min to 29.47 μg/min. The emission rates of the elements varied between 0.01 ng/min and 9.57 μg/min and S, Ca, Na, K, Al, Mg, and Fe were the most abundant elements in cooking profiles. The total emission rates of the 16 PAHs in PM2.5 ranged between 8.83 ng/min and 241.06 ng/min and Nap, Pyr, Chr, BghiP, and Phe were the main PAHs released from residential cooking. Thereinto, Nap and Phe could be utilized as organic markers to distinguish between cooking and other non-cooking source emissions. These findings could assist in the determination of the concentrations of PM2.5-bound chemicals in regard to emission control strategies, as well as in the assessment of health risks.