Polycyclic and nitro-polycyclic aromatic hydrocarbon pollution characteristics and carcinogenic risk assessment of indoor kitchen air during cooking periods in rural households in North China

Medium-flow atmospheric samplers were used to collect particulate (PM2.5) and gaseous samples from the indoor kitchen of each of 35 randomly selected rural houses in North China while a meal was being cooked. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) and 9 nitro-PAHs (NPAHs) in the samples were quantified by high-performance liquid chromatography (HPLC). This study provided the real PAH and NPAH pollution characteristics and carcinogenic risk produced by cooking in rural indoor kitchens in North China. The mean PAH and NPAH concentrations in air in the indoor kitchens during cooking periods were 4049.1 and 1741.6 ng/m(3), respectively. The PAH and NPAH concentrations were lower in the particulate phase than the gaseous phase. The mean PAH and NPAH concentrations were much higher for cooking using coal than for cooking using liquefied petroleum gas (LPG) or electricity. The PAH and NPAH benzo[a]pyrene toxic equivalent (TEQ(BaP)) concentrations for cooking using coal were 1823.3 and 2760.9 ng/m(3), respectively. Lower PAH and NPAH concentrations were found in kitchens with than without range hoods. Range hoods decreased the PAH and NPAH TEQ(BaP) concentrations by 68.8% and 61.9%, respectively. Appropriate fuel and ventilation choice will improve air pollution in indoor kitchens during cooking. The results provide important evidence for changing cooking habits and developing policies for cooking in rural China.

Automated summary

Medium-flow atmospheric samplers were used to collect particulate (PM2.5) and gaseous samples from indoor kitchens in 35 randomly selected rural houses in North China. Analysis showed that cooking with coal resulted in significantly higher PAH and NPAH concentrations compared to cooking with LPG or electricity, while the use of range hoods and proper ventilation can reduce the levels of PAH and NPAH during cooking.