Supporting Information for

Transcription

1 S1 Supporting Information for Emission Rates of Multiple Air Pollutants Generated from Chinese Residential Cooking Chen Chen,, Yuejing Zhao,, Bin Zhao *,, Department of Building Science, School of Architecture, Tsinghua University, Beijing, , China. Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, , China. SUMMARY OF CONTENTS SURVEY RESULTS OF COOKING BEHAVIORS... S2 ORTHOGONAL TEST DESIGN... S3 DETERMINATION OF EMISSION RATES WITH THE RANGE HOOD ON... S4 1) Emission rate of particulate matter... S4 2) Emission rate of gaseous pollutants... S4 UNIFORMITY OF SPATIAL PM CONCENTRATIONS... S6 THE MEASURING PROCEDURES... S7 AIR POLLUTANT EMISSION RATES GENERATED FROM TYPICAL CHINESE COOKING... S8 COMPARISON OF EMISSION RATES WITH PREVIOUS STUDIES... S22 SURVEY RESULTS OF RANGE HOODS... S23 THE DURATION TIME OF TYPICAL CHINESE COOKING... S24 THE AIR CHANGE RATE DURING MEASUREMENT... S25 COMPARISONS OF FLOW RATE AND THE EFFICIENCY OF RANGE HOOD WITH PREVIOUS STUDIES... S26 COMPARISON BETWEEN TWO AM510 MONITORS... S27 Number of pages: 29 Number of figures: 8 Number of tables: 14

2 S2 SURVEY RESULTS OF COOKING BEHAVIORS Table S1. Survey results of household energy preferences in Chinese residences Opening behavior Natural gas Liquefied Petroleum Gas Electricity Others The most popular choice 66.7% 19.3% 12.9% 1.2% Table S2. Survey results of cooking method preferences and occupation during cooking in Chinese residences Cooking Methods Stir-frying Pan-frying Deep-frying Steaming Boiling Stewing Others The most popular choice 84.6% 1.0% 0.3% 2.7% 9.4% 2.0% 0.0% Waiting in kitchen 96.9% 83.1% 82.9% 14.4% 24.5% 8.8% 37.5% Table S3. Survey results of ingredient weight preferences in Chinese residences Ingredient weight The most popular choice For 1 person For 2 persons For 3 persons For 4 persons For 5 persons For 6 persons 4.7% 22.5% 45.0% 19.1% 6.4% 2.3% Table S4. Survey results of meat type preferences in Chinese residences Type of meat Pork Beef Mutton Fish Chicken Duck Others The most popular choice 78.5% 9.1% 1.0% 7.0% 3.7% 0.7% 0.0% Table S5. Survey results of oil type preferences in Chinese residences Type of Oil Peanut oil Blend oil a Canola oil Sunflower oil Soybean oil Olive oil Others The most popular choice 43.6% 21.1% 13.1% 8.4% 5.7% 5.7% 2.3% a Blend oil: oil made from two or more vegetable oil.

3 S3 ORTHOGONAL TEST DESIGN Table S6. The Orthogonal Design of Chinese Recipes No. Cooking method Ingredient weight a Type of meat Type of oil Meat/vegetable ratio b Blank 1 Boiling For 2 persons Fish Canola oil Deep-frying For 4 persons Pork Canola oil Boiling For 1 person Pork Soybean oil Steaming For 1 person Mutton Sunflower oil Boiling For 5 persons Chicken Peanut oil Pan-frying For 1 person Chicken Canola oil Deep-frying For 2 persons Mutton Peanut oil Pan-frying For 5 persons Mutton Soybean oil Steaming For 5 persons Beef Canola oil Stir-frying For 4 persons Chicken Sunflower oil Stir-frying For 3 persons Mutton Canola oil Boiling For 3 persons Beef Sunflower oil Pan-frying For 2 persons Pork Sunflower oil Deep-frying For 5 persons Fish Sunflower oil Deep-frying For 1 person Beef Blend oil Pan-frying For 3 persons Fish Blend oil Steaming For 2 persons Chicken Blend oil Deep-frying For 3 persons Chicken Soybean oil Stir-frying For 1 person Fish Peanut oil Boiling For 4 persons Mutton Blend oil Pan-frying For 4 persons Beef Peanut oil Stir-frying For 5 persons Pork Blend oil Stir-frying For 2 persons Beef Soybean oil Steaming For 4 persons Fish Soybean oil Steaming For 3 persons Pork Peanut oil a According to the professional cook who performed the cooking in the experiments, the suggestive value of total ingredient weight per person is 120 g. b If the meat/vegetable ratio is zero, only vegetables were used.

4 S4 DETERMINATION OF EMISSION RATES WITH THE RANGE HOOD ON 1) Emission rate of particulate matter Assuming that air is well mixed in the kitchen and the ambient concentration is steady, the mass balance equation for PM 2.5 and UFPs when the range hood on can be expressed as: dcin, p t Q S p QexC ex in, p t PC out a C in, p t (S1) dt V V where C in,p (t) is the real-time indoor concentration of particulate matter at the measuring moment t, Q ex is the exhaust air volume rate of the range hood, V is the volume of the kitchen, P is the penetration factor of outdoor particles entering the indoor environment through the building envelope, C out is the outdoor concentration of particulate matter, λ is the total removal rate due to coagulation, deposition and air change rate in the kitchen, and S hood,p is the emission rate of particulate matter with the range hood on. The emission rate of particulate matter S hood,p measured with the range hood on is defined as: hood, p p ex in, p S S Q C t (S2) The emission rate of particulate matter S hood,p is influenced by the concentration of PM 2.5 and UFP in the exhaust air, which changes over time. In order to compare it with the emission rate generated from cooking. The emission rate of particulate matter S hood,p is approximately estimated as a constant from the solution of indoor PM 2.5 or UFP concentration for equation (S1) is: Qex Shood, p a t Qe x Shood, p Cin, p t Cin, p t0 Cba e C a a V a V a a a V lance (S3) balance V 2) Emission rate of gaseous pollutants Assuming that air is well mixed in the kitchen and the ambient concentration is steady, the mass balance equation for gaseous pollutants when the range hood on can be expressed as: dcin, g t Shood, g QexCin, g t (S4) dt V where C in,g (t) is the real-time indoor concentration of gaseous pollutants at the measuring moment t, and S hood,g is the emission rate of gaseous pollutants with the range hood on. The emission rate of gaseous pollutants S hood,g measured with the range hood on is defined as: hood, g g ex in, g S S Q C t (S5)

5 S5 The emission rate S hood,g is influenced by the concentration of gaseous pollutants in the exhaust air, which changes over time. In order to compare it with the emission rate generated from cooking. The emission rate of particulate matter S hood,g is approximately calculated as a constant: 2V S C C t t hood, g in, g in, g 0 (S6)

6 S6 UNIFORMITY OF SPATIAL PM CONCENTRATIONS Unit: mm : Range hood : Pan : Door : Refrigerator : Fan : Cupboard : Stove : Window : Washer : Measurement point Figure S1-(a). Layout of the residential kitchen (plan view). Figure S1-(b). Comparison between PM 2.5 concentrations measured in two points.

7 S7 THE MEASURING PROCEDURES Figure S2. The measurement procedures.

8 S8 AIR POLLUTANT EMISSION RATES GENERATED FROM TYPICAL CHINESE COOKING Table S7. PM 2.5 emission rates generated from typical Chinese cooking No. Cooking method 1 st measurement 2 nd measurement 3 rd measurement a S (mg/min) S (mg/min) SE b (mg/min) R 2 S (mg/min) SE (mg/min) R 2 S (mg/min) SE (mg/min) R 2 (Mean ± SD c ) 1 boiling ± deep-frying ± boiling ± steaming E ± boiling ± pan-frying ± deep-frying ± pan-frying ± steaming ± stir-frying ± stir-frying ± boiling E ± pan-frying ± deep-frying ± deep-frying ± pan-frying ± steaming ± deep-frying ± stir-frying ± boiling E ± pan-frying ± stir-frying ± 0.987

9 S9 23 stir-frying ± steaming ± steaming ± a The blank in the column means no measurement. b Standard error of estimate. c Standard deviation of results.

10 S10 Table S8. UFP emission rates generated from typical Chinese cooking No. Cooking method 2 nd measurement 3 rd measurement a S ( #/min) S ( #/min) SE b ( #/min) R 2 S ( #/min) SE ( #/min) R 2 (Mean ± SD c ) 1 boiling deep-frying ± boiling steaming boiling pan-frying ± deep-frying ± pan-frying ± steaming stir-frying ± stir-frying ± boiling pan-frying ± deep-frying ± deep-frying ± pan-frying ± steaming deep-frying ± stir-frying ± boiling pan-frying ± stir-frying ± stir-frying ± 0.149

11 S11 24 steaming steaming a The blank in the column means no measurement. b Standard error of estimate. c Standard deviation of results.

12 S12 Table S9. Formaldehyde emission rates generated from typical Chinese cooking (Unit: mg/min) No. Cooking method 1st measurement 2nd measurement 3rd measurement b Mean ± SD c 1 boiling ± deep-frying ± boiling ± steaming ± boiling ± pan-frying ± deep-frying ± pan-frying ± steaming ± stir-frying ± stir-frying ± boiling ± pan-frying ± deep-frying ± deep-frying ± pan-frying ± steaming ± deep-frying ± stir-frying ± boiling ± pan-frying ± stir-frying ± stir-frying ± steaming ± 0.533

13 S13 25 steaming ± a Lost data. b The blank in the column means no measurement. c Standard deviation of results.

14 S14 Table S10. Benzene emission rates generated from typical Chinese cooking (Unit: mg/min) No. Cooking method 1st measurement b 2nd measurement 3rd measurement b Mean ± SD c 1 boiling deep-frying ± boiling steaming ± boiling pan-frying ± deep-frying ± pan-frying ± steaming ± stir-frying ± stir-frying Lost a ± boiling pan-frying ± deep-frying ± deep-frying ± pan-frying ± steaming ± deep-frying ± stir-frying ± boiling pan-frying ± stir-frying ± stir-frying ± steaming ± 0.014

15 S15 25 steaming ± a Lost data. b The blank in the column means no measurement. c Standard deviation of results.

16 S16 Figure S3. Emission rates of benzene generated from Chinese cooking (factors sorted from the largest F value to the smallest one)

17 S17 Table S11. Toluene emission rates generated from typical Chinese cooking (Unit: mg/min) No. Cooking method 1st measurement b 2nd measurement 3rd measurement b Mean ± SD c 1 boiling deep-frying ± boiling steaming ± boiling pan-frying ± deep-frying ± pan-frying ± steaming stir-frying ± stir-frying Lost a ± boiling pan-frying ± deep-frying ± deep-frying ± pan-frying ± steaming deep-frying ± stir-frying ± boiling pan-frying ± stir-frying ± stir-frying ± steaming ± 0.002

18 S18 25 steaming ± a Lost data. b The blank in the column means no measurement. c Standard deviation of results.

19 S19 Figure S4. Emission rates of toluene generated from Chinese cooking (factors sorted from the largest F value to the smallest one).

20 S20 Table S12. TVOC emission rates generated from typical Chinese cooking (Unit: mg/min) No. Cooking method 1st measurement b 2nd measurement 3rd measurement b Mean ± SD c 1 boiling deep-frying ± boiling steaming ± boiling pan-frying ± deep-frying ± pan-frying ± steaming ± stir-frying ± stir-frying ± boiling pan-frying ± deep-frying ± deep-frying ± pan-frying ± steaming ± deep-frying ± stir-frying ± boiling pan-frying ± stir-frying ± stir-frying ± steaming ± 0.091

21 S21 25 steaming ± a Lost data. b The blank in the column means no measurement. c Standard deviation of results.

22 S22 COMPARISON OF EMISSION RATES WITH PREVIOUS STUDIES Figure S5. Comparison of emission rates with previous studies 1-11.

23 S23 SURVEY RESULTS OF RANGE HOODS We have reviewed the top 165 best-selling range hoods whose sales reached up to 90% online. The survey results of range hood exhaust rate were summarized, which is shown in Figure S6. The exhaust rate of range hoods was ± m 3 /min. Figure S6. Survey results of range hood exhaust rate preferences in Chinese residences.

24 S24 THE DURATION TIME OF TYPICAL CHINESE COOKING Table S13. The duration time of typical Chinese cooking (Unit: min) No. Cooking method 1st measurement 2nd measurement 3rd measurement a Mean ± SD b 1 boiling ± deep-frying ± boiling ± steaming ± boiling ± pan-frying ± deep-frying ± pan-frying ± steaming ± stir-frying ± stir-frying ± boiling ± pan-frying ± deep-frying ± deep-frying ± pan-frying ± steaming ± deep-frying ± stir-frying ± boiling ± pan-frying ± stir-frying ± stir-frying ± steaming ± steaming ± a The blank in the column means no measurement. b Standard deviation of results.

25 S25 THE AIR CHANGE RATE DURING MEASUREMENT Table S14. The air change rate during measurement (Unit: h -1 ) No. Cooking method 1st measurement 2nd measurement 3rd measurement a 1 boiling deep-frying boiling steaming boiling pan-frying deep-frying pan-frying steaming stir-frying stir-frying boiling pan-frying deep-frying deep-frying pan-frying steaming deep-frying stir-frying boiling pan-frying stir-frying stir-frying steaming steaming a The blank in the column means no measurement.

26 S26 COMPARISONS OF FLOW RATE AND THE EFFICIENCY OF RANGE HOOD WITH PREVIOUS STUDIES 120 Removal performance of the range hood (%) Rim et al., 2012 Singer et al., Singer et al., 2017 This study Exhaust flow rate (m 3 /min) Figure S7. Comparisons of flow rate and the efficiency of range hood with previous studies

27 S27 COMPARISON BETWEEN TWO AM510 MONITORS The results of the AM510 monitor used in the measurements were compared with an AM510 monitor calibrated in July 5, 2017 (shown in Figure S8). The measured results were well fitted and all the results measured with the old AM510 were modified base on the linear relationship. Then, the modified results were calibrated against the gravimetric measurements. Figure S8. Comparison between two AM510 monitors.

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