Pm_1.0 Emission From Cooking Oil Fumes And Characteristics Of Solid PAHs

Particulate matter is the main pollutant that affects indoor air quality,and cooking oil fume is one of the main sources of indoor air particulate matter.It is easy to absorb harmful substances on the surface of particles,especially the harmful substances such as particulates and polycyclic aromatic hydrocarbons released from cooking oil fumes,which are harmful to the human body.Therefore,it is of great significance to understand the emission characteristics of particulate matter released by cooking oil fumes and solid PAHs.To clarify the emission characteristics of particulate matter and PAHs emitted by different cooking oils at different kinds of cooking temperature,the concentrations of PM_1.0,PM_2.5and PM₁₀ released from 7 kinds of cooking oil,such as soybean oil,soybean oil（grade III）,sunflower oil,peanut oil,rapeseed oil,blended oil and lard,were tested by portable particulate matter analyzer in a clean environment cabin of8m³ at three different kinds of heating temperature（190℃,220℃and 260℃）.The variation of PM_1.0 mass concentration with time and the particle size distribution of PM_1.0/PM_2.5 and PM_2.5/PM₁₀ was analyzed.In addition,PM_2.5 samples from the typical lampblack were collected by impinging particulate matter sampler,and 16 kinds of optimal PAHs were extracted and analyzed by GC-MS.Then,according to the indoor pollutant balance equation,the emission characteristics of PM_1.0 from cooking oil heated in different kinds of temperature were analyzed,and the emission characteristics and exposure risk of solid PAHs were studied.Finally,the concentrations of PM_1.0produced by seven kinds of oil in different rooms,different ventilation times and different kinds of temperature were predicted.The main conclusions are as follows:（1）The mass concentration of PM_1.0 released from 7 kinds of cooking oil at three kinds of cooking temperature showed a peak shape with time.At 190℃,220℃and 260℃,the peak concentrations of PM_1.0 of different oil were 0.101～1.230 mg/m³、0.228～5.72 mg/m³ and1.950～17.500 mg/m³,respectively.The peak concentrations of peanut oil,sunflower oil and lard were relatively high,and the peak concentrations of soybean oil were the lowest.（2）PM_1.0 was the main particulate matter emitted by oil fume at different kinds of temperature.The average ratio of PM_1.0/PM_2.5 was 0.99185,and the average ratio of PM_2.5/PM₁₀was 0.99582.However,the variations of PM_1.0/PM_2.5 and PM_2.5/PM₁₀ with temperature and time were not consistent.（3）When the cooking temperature was 190℃,the PM_1.0 emission rate range of different kinds of cooking oil was 4.444～30.464 mg/h,the average value is 13.838 mg/h;the emission factor range was 0.044～0.305 mg/（g·h）,The average value was 0.138 mg/（g·h）.When the cooking temperature was 220℃,the PM_1.0 emission rate range was 5.331～135.235 mg/h,the average value was 43.369 mg/h;the emission factor range was 0.053～1.352 mg/（g·h）,the average value is 0.433 mg/（g·h）.When the cooking temperature was 260℃,the PM_1.0 emission rate range was 45.002～304.059 mg/h,the average value was 209.868 mg/h;the emission factor range was 0.450～3.981 mg/（g·h）,the average value was 2.099 mg/（g·h）.The emission rate and emission factor of PM_1.0 increase with the increase of oil temperature,but the emission rate and emission factor of PM_1.0 of different cooking oils are not synchronized with temperature changes,and at the same cooking temperature,the emission factor of PM_1.0 is directly proportional to the heating time at the same cooking temperature.（4）The emission factors of solid PAHs released from typical cooking oils heated at 260℃for 30 min ranged from 0.469 to 0.965μg/kg,with an average of 0.800μg/kg.The main monomeric PAHs were Phe,Flu,Phr,Fluo and Chr.The content of PAHs released from lard was less than that from vegetable oil.（5）The average concentration of solid PAHs produced by sunflower oil and blended oil was 3.661 ng/m³ and 1.803 ng/m³,respectively.The toxic equivalent dose was 0.002 ng/m³ and0.005 ng/m³,respectively.The equivalent toxicity was not proportional to the concentration of PAHs.（6）Increasing ventilation frequency and room volume was beneficial to reduce the level of particulate matter concentration,but when ventilation frequency reached a certain value,the dilution effect on particulate matter concentration remained basically unchanged.（7）The research results show that the oil temperature should be reduced during cooking,the cooking time should be shortened,and the number of ventilation should be appropriately increased to reduce the harm of pollutants to the human body.The corresponding relationship between cooking oil fume and particulate matter,PAHs should be studied.