New study shows high levels of carbon monoxide in Nairobi

A new study now suggests that household air pollution caused by cooking is the main source of carbon monoxide (CO) exposure for school-going children in Nairobi.

The study, named Tupumue, a Kiswahili word meaning “let us breathe”, sought to determine the burden and determinants of early life and air pollution concentrations that were measured over 24 hours in nearly 200 households in Nairobi.

It notes that although the majority of urban households in the two contrasting study areas (an informal and a more affluent Nairobi settlement) use liquid or gaseous fuels, carbon monoxide level concentrations were comparable to those previously reported. in rural households that predominantly use more polluting solid fuels such as coal and wood.

“CO concentrations within Nairobi homes are substantial and have the potential to affect population health and mortality,” part of the study reads.

Carbon monoxide is a poisonous gas produced by the incomplete combustion of carbon-based fuels burned in poorly ventilated stoves and has chronic health effects, particularly in terms of child development.

It is known as the “silent killer” as it is odorless and colorless.

Air pollution is estimated to kill 6.7 million people annually, of which approximately 2.3 million are due to household air pollution.

The study has just been published in the scientific journal Environmental Pollution and is a multidisciplinary study bringing together Kenyan researchers, including those from KEMRI, and their UK counterparts from the Liverpool School of Tropical Medicine, Stockholm Environmental Institute and the University of Stirling, among others.

The Tupumue project recruited 2,373 children (1,277 from Mukuru area, 1,096 from Buru Buru) aged between 5 and 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 problems and data loss, complete 24-hour CO data was available for 138 of these households (67 in Buru Buru and 71 in Mukuru).

The population characteristics of this sample were representative of the broader Tupumue cohort.

“Of the 138 homes where continuous data was available, 134 (97%) had a measurable CO indication (i.e., a minute in which CO exceeded the sampler’s detection limit of 0.5 ppm),” it reads in part. of the study.

Ethical approvals were provided by the Kemri Scientific and Ethical Review Unit.

Parents/guardians provided written informed consent and children provided written informed consent.

Trained field workers recruited from the two communities installed factory-calibrated devices in homes.

Participating children wore the Lascar devices attached to a bracelet on their upper arms when they were at home; At other times, the device remained in the house and was placed within the main living room using locally manufactured stands to ensure that the devices were 1 m from the floor and, where possible, at least 1 m from sources (e.g. example, a stove) or open doors. or windows.

The goal was to collect a full 24-hour period of data from each household.

The measurements were carried out between June and December 2021.

Mukuru is a large informal settlement covering approximately 450 acres in a heavily industrialized area. Housing here is high-density and low-quality, with poor sanitary conditions and a lack of many basic services. Buru Buru is a neighboring, relatively prosperous and planned residential neighborhood.

“The study established that a substantial proportion of homes (almost 1 in 10) had concentrations that would trigger a European standard carbon monoxide alarm, suggesting that there is likely to be a considerable and unquantified health burden from exposure.” acute to carbon monoxide and carbon monoxide. poisoning.”

“The study underscores the urgent need to address household air pollution in urban environments with targeted interventions essential to mitigate carbon monoxide exposure and safeguard public health, as this study corroborates findings suggesting that fuels’ ‘cleaner’ do not always generate the desired levels of reduction. in air pollution in homes. “There is a need to better understand carbon monoxide exposure in urban settings and target interventions, including community education on home air pollution, that reduce exposure to evening cooking activity within the home,” says part of the report. study.