- The Tupumue project recruited 2,373 children (1,277 from the Mukuru area; 1,096 from Buru Buru) aged 5–18 years attending school in Nairobi.
- In total, 179 households volunteered for detailed air quality monitoring (88 in Buru Buru and 91 in Mukuru).
A new study now suggests that household air pollution from cooking is the main source of carbon monoxide (CO) exposure for school-going children in Nairobi.
The study, christened Tupumue, a Kiswahili word meaning ‘let us breathe', sought to determine the burden and early life determinants and air pollution concentrations that were measured for 24 hours in nearly 200 homes in Nairobi.
It notes that despite most of the urban homes in the two contrasting study areas—an informal and a more affluent settlement of Nairobi—using liquid or gas fuels, concentrations of carbon monoxide levels were comparable with those previously reported in rural homes that predominantly use more polluting solid fuels such as charcoal and wood.
“CO concentrations within homes in Nairobi are substantial and have the potential to impact the health and mortality of the population,” part of the study says.
Carbon monoxide is a poisonous gas produced by the incomplete combustion of carbon-based fuels burning on poorly ventilated stoves and chronic health effects, particularly in terms of child development.
It is known as the "silent killer" as it is odourless and colourless.
Air pollution kills an estimated 6.7 million people per year, with approximately 2.3 million of those deaths arising from household air pollution.
The study has just been published in the Environmental Pollution scientific journal and is a multidisciplinary study bringing together researchers from Kenya, including those from KEMRI, and their United Kingdom counterparts from the Liverpool School of Tropical Medicine, the Stockholm Environmental Institute, and the University of Stirling, among others.
The Tupumue project recruited 2,373 children (1,277 from the Mukuru area, 1,096 from Buru Buru) aged 5–18 years attending school in Nairobi.
In total, 179 households volunteered for detailed air quality monitoring (88 in Buru Buru and 91 in Mukuru).
The study says that due to logistical issues and data loss, full 24-hour CO data were available from 138 of these homes (67 in Buru Buru and 71 in Mukuru).
The population characteristics of this sample were representative of the wider Tupumue cohort.
“Of the 138 homes where continuous data were available, 134 (97%) had an indication of measurable CO (that is, one minute where CO exceeded the sampler detection limit of 0.5 ppm),” part of the study says.
Ethical approvals were provided by the Kemri Scientific and Ethics Review Unit.
Parents/guardians provided written informed consent, with children providing written assent.
Factory-calibrated devices were installed in homes by trained field workers recruited from the two communities.
The Lascar devices were worn by the participating child attached to an armband on the upper arm when they were at home; at other times, the device remained in the home and was positioned within the main living area using locally manufactured stands to ensure devices were 1m from the ground and, where practicable, at least 1m from sources (for example, a stove) or open doors or windows.
The aim was to gather a full 24-hour period of data from each home.
Measurements took place between June and December 2021.
Mukuru is a large informal settlement covering approximately 450 acres in a heavily industrialised area. Housing here is high density and of low quality, with poor sanitation and a lack of many basic amenities. Buru Buru is a neighbouring, relatively affluent, planned, residential neighbourhood.
“The study established that a substantial proportion of homes (nearly 1 in 10) had concentrations that would activate a European-standard carbon monoxide alarm, suggesting that there is likely to be a considerable unquantified burden on health from acute carbon monoxide exposure and carbon monoxide poisoning.”
“The study underscores the urgent need to address household air pollution in urban settings with targeted interventions essential to mitigate carbon monoxide exposure and safeguard public health, as this study corroborates findings that suggest that ‘cleaner’ fuels do not always generate the desired levels of reduction in household air pollution. There is a need to better understand carbon monoxide exposures in urban settings and to target interventions, including community education on household air pollution, that reduce exposure from evening cooking activity within the home,” part of the study says.