CO2 exposure, ventilation, thermal comfort and health risks in low-income home kitchens of twelve global cities
Prashant Kumar, Sarkawt Hama, Rana Alaa Abbass, Thiago Nogueira, Veronika S. Brand, Huai-Wen Wu, Francis Olawale Abulude, Adedeji A. Adelodun, María de Fátima Andrade, Araya Asfaw, Kosar Hikmat Hama Aziz, Shi‐Jie Cao, Ahmed El-Gendy, Gopika Indu, Anderson Gwanyebit Kehbila, Fryad S. Mustafa, Adamson S. Muula, Samiha Nahian, Adelaide Cássia Nardocci, William Nelson, Aiwerasia Vera Ngowi, Yris Olaya, Khalid M. Omer, Philip Osano, Abdus Salam, S. M. Shiva Nagendra
Abstract
In-kitchen air pollution is a leading environmental issue, attributable to extensive cooking, poor ventilation and the use of polluting fuels. We carried out a week-long monitoring of CO2, temperature and relative humidity (RH) in five low-income residential kitchens of 12 global cities (Dhaka, Chennai, Nanjing, Medellín, São Paulo, Cairo, Sulaymaniyah, Addis Ababa, Nairobi, Blantyre, Akure and Dar-es-Salaam). During cooking, the average in-kitchen CO2 concentrations were 22.2% higher than the daily indoor average. Also, the highest CO2 was observed for NVd (natural ventilation-door only; 711 ± 302 ppm), followed by NVdw (natural ventilation-door + window; 690 ± 319 ppm) and DVmn (dual ventilation-mechanical + natural; 677 ± 219 ppm). Using LPG and electric appliances during cooking exhibited 32.2% less CO2 than kerosene. Larger kitchens (46–120 m3) evinced 28% and 20% less CO2 than medium (16–45 m3) and small (4–15 m3) ones, respectively. In-kitchen CO2 with >2 occupants during cooking was 7% higher than that with one occupant. 87% of total kitchens exceeded the ASHRAE standard (RH >40%, temperature >23 °C) for thermal comfort. Considering the ventilation type, both the ACH (air change rate per hour) and ventilation rate followed the order: NVdw > NVd > DVmn, while the trend for weekly average CO2 concentration was NVd > DVmn > NVdw. Larger kitchens presented 22% and 28% less ACH, and 82% and 190% higher ventilation rate than medium- and small-volume ones, respectively. Forty-three percent kitchens had ACH <3 h−1 and ventilation rate <4 L/s/person, hence violated the conditions for ideal ventilation. Moreover, 10% of the Hazard Ratio values for 25% kitchens exceeded the CO2 reference value (1000 ppm). Consequently, our findings prompted several recommendations towards improving in-kitchen ventilation and environmental conditions of low-income homes.