Spatio-Temporal Variation in the Concentration of Inhalable Particulate Matter (PM10) in Uganda

Abstract

Long-term particulate matter (PM10) measurements were conducted during the period January 2016 to September 2017 at three sites in Uganda (Mbarara, Kyebando, and Rubindi) representing a wide range of urbanization. Spatial, temporal and diurnal variations are assessed in this paper. Particulate matter (PM10) samples were collected for 24-h periods on PTFE filters using a calibrated pump and analyzed gravimetrically to determine the average density. Particulate levels were monitored simultaneously using a light scattering instrument to acquire real time data from which diurnal variations were assessed. The PM10 levels averaged over the sampling period at Mbarara, Kyebando, and Rubindi were 5.8, 8.4, and 6.5 times higher than the WHO annual air quality guideline of 20 µg·m−3, and values exceeded the 24-h mean PM10 guideline of 50 µg·m−3 on 83, 100, and 86% of the sampling days. Higher concentrations were observed during dry seasons at all sites. Seasonal differences were statistically significant at Rubindi and Kyebando. Bimodal peaks were observed in the diurnal analysis with higher morning peaks at Mbarara and Kyebando, which points to the impact of traffic sources, while the higher evening peak at Rubindi points to the influence of dust suspension, roadside cooking and open-air waste burning. Long-term measurement showed unhealthy ambient air in all three locations tested in Uganda, with significant spatial and seasonal differences.

Spatial-temporal patterns of ambient fine particulate matter (PM2.5) and black carbon (BC) pollution in Accra

“…high temperature, low wind-speed and absence of precipitation) may produce stagnant conditions that substantially amplify local anthropogenic emissions [ 56 ]. The daily PM 2.5 cycle of bimodal pattern with peaks in the mornings and evenings, provides further support for the influence of rush hour traffic, biomass combustion as well as pollution build-up due to temperature inversion and variations in meteorological conditions between day and nighttime hours and seasons [ 23 , 57 ]. It is likely that the observed improvements in PM 2.5 pollution, especially in high-density neighborhoods that also tended to have high-biomass use, was due to gradual reductions in biomass use.…”

Emerging Pollutants in Uganda: A Systematic Review

“…The review identified reports on disinfection byproducts, such as trihalomethanes (THMs), in drinking water supplies (122). In addition, particulate matter, including fine and coarse particulates (PM2.5 and PM10), was also a subject of investigation in air quality studies (98,124,125).…”

“…Airborne particles and gases can carry pollutants such as persistent organic pollutants (POPs) and microplastics over long distances, leading to their deposition in ecosystems, including water bodies and soils. Study conducted by (124,125), 152.6 µg/m 3 of PM2.5 and 208 µg/m 3 of PM10 were measured in air samples around the districts of Kampala, Jinja and Mbarara in Uganda. This review identified that a few studies investigating airborne emerging pollutants have so far been done.…”

Validation of the Atmospheric Boundary Layer Height Estimated from the MODIS Atmospheric Profile Data at an Equatorial Site

“…PM 10 data were collected from three sites with a real-time monitor (TSI SidePak AM510) using an impactor with a 10 µm cut-off, as described in [21]. The sites were in Mbarara, Rubindi, and Kyebando.…”