Master's lecture in Environment and Natural Resources - Harriet Naa Teckie Botchway
The lecture will be streamed: https://us02web.zoom.us/j/8199368234?pwd=T2d1MUYvbEpaQkJPUFpJMkt3eHdLUT09
Master's student: Harriet Naa Teckie Botchway
Title: Sources of Particulate Matter (PM10) in Reykjavik on days exceeding the health limit and in Accra 2015 and recommendations for Ghana’s air quality policy development
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Faculty: Faculty of Earth Sciences
Advisor: Þröstur Þorsteinsson, Professor in Environment and Natural Resources
Examiner: Kristín Lóa Ólafsdóttir, Project Manager at Heilbrigðiseftirlit Reykjavíkur
Abstract
Exceedances of particulate matter (PM10) health limit and finding ways to reduce the sources of ambient particulate matter in Reykjavik, Iceland and Accra, Ghana, has been of major concern over the years. Iceland has been able to implement the use of electric cars to reduce exhaust emissions, which enhances the Environmental Performance Index of Iceland towards the achievement of sustainable ‘‘pollution-free’’ environment. As a developing country, Ghana’s inadequate resources has resorted to the consistent use of low-cost air quality sensors and monitors to measure and identify possible sources of PM10 pollution.
This research focuses on local and remote sources that contributed to the exceedance of PM10 concentrations over the 24-hour health limit in 2015 in Reykjavik and the impacts of weather on the concentrations. Three PM10 data sets (GRE, FHG and Model results) and meteorological data from GRE and IMO (back-up data) were used to assess the impacts of weather conditions on the PM10 concentrations.
PM10 concentrations measured at GRE station were compared with predicted PM10 model results to ascertain how well the model works in predicting PM10. The model only accounts for traffic related pollution; including local resuspension events at GRE station only. Out of 328 monitoring days, nine (9) days were observed to have exceeded the PM10 24-hour health limit of 50 µg/m³ at GRE monitoring station and two (2) days were exceeded at FHG monitoring stations. However, both GRE and FHG stations recorded 15th June 2015 as a day of exceedance thus, a total of 10 exceedance days in 2015. Measured PM10 levels for these 10 days ranged from 52.2 µg/m³ to 116.0 µg/m³ at GRE station. A series of daily PM10 data at GRE station were missing from 5th March through to 11th April 2015 due to equipment failure.
Main sources of PM10 pollution for the 10 exceedance days were anthropogenic (traffic emissions and resuspension events: 6 days and construction activities: 1 day) with few occurrences of natural events (dust storm: 3 days). PM10 concentrations from traffic exhaust follow the gaussian distribution plume model. Some weather parameters (precipitation and wind speed) affected PM10 levels on the exceedance days. Generally, model results underestimated PM10 concentrations from traffic emissions and resuspension events with wind speed ≥5 m/s. These results are useful in future environmental policy decisions for incorporating weather conditions as key environmental indicator of PM10 pollution.
The 2015 annual average PM10 concentrations measured in Ghana and Iceland were recorded as 172 µg/m³ and 18 µg/m³, respectively. Anthropogenic sources of PM10 are the main contributors of particulate matter pollution in Accra which includes traffic emissions, use of coal, open fire burning of waste and fish smoking (small scale business operation). Policy measures have been implemented by the government of Ghana to curb this situation and this research adds to the existing policy measures of air pollution in Ghana.