Lockdown: City air improves by 40%

A deserted section of Luwum Street which is usually one of the busiest trading centres in Kampala. PHOTO BY ERIC DOMINIC BUKENYA

The quality of air in Kampala has improved by 40 per cent during the Covid-19 lockdown, says a report by AirQo, a specialised air quality monitoring centre based at Makerere University.

Prof Engineer Bainomugisha, the AirQo project lead, said the data was generated from network of seven air quality monitoring machines planted in greater Kampala.

AirQo is a project funded by Google with air quality monitoring devices in Nsambya (US Embassy), Civic Centre, Bugolobi, Seguku,Bweyogerere and Kiwafu in Entebbe and some upcountry areas.

“We compared air quality for the lockdown period from March 18 to April 4 with the preceding two weeks [March 4-18],” he said.
“We also looked at historical results for the same days in 2019. Finally, we examined one-year seasonal longitudinal variations,” Prof Bainomugisha added.

He said during data analysis, a drastic improvement in air quality was observed.
“We noticed a drastic drop of 40 per cent in the daily pollution levels from period of official closure of public gatherings and lockdown,” the professor said.

“In the preliminary validation with historical comparisons for the same days for last year 2019, there was 51 per cent reduction in the level of pollution,” he added.

More effort needed
Mr Deo Okure, the air quality scientist and member of the project, said a lot of effort is still needed to reach World Health Organisation (WHO) standard limit of pollution.

“While air quality noticeably improved during the lockdown, some daily levels have still been above 25gm-3, what WHO considers to be acceptable,” he said.

“The one-year longitudinal datasets even indicate much stronger exceeding of the WHO annual limit of 10gm-3,” Mr Okure added.
“For instance, in areas such as Nsambya, Bweyogerere and Bugolobi, emissions in the morning rush hour between 6am and 9am dropped by around 60 per cent,” Mr Okure said, adding that in those locations in the evening, there is little difference between the lockdown and the period before.

The scientists said the heavy emissions noted in the evening hours must be coming from homes.
“This suggests that the morning peak is caused by vehicle traffic while the evening emissions relate more to domestic fuel used although confirming requires more investigation,” he said.

More than 90 per cent of households in Uganda use solid biomass such as charcoal and firewood for cooking and heating yet these have high pollution intensity.

Mr Okure said in Seguku on Entebbe Road, very little improvement in air quality was seen.
“The trunk road that connects Kampala and Entebbe municipality including the airport has heavier traffic than most of the regular major roads,” he said.