Arba Minch University and units of Lund University, Sweden, have signed a Memorandum of Understanding (MOU). From Lund, these are the Unit of Environment, Society and Health (Division of Occupational and Environmental Medicine) and the Unit of Ergonomics and Aerosol Technology (Department of Design Sciences). From Arba Minch University, this are the Arba Minch Water Technology Institute (of which I am part) and the School of Public Health.
I came into contact with representatives of Lund University through their co-organized international conference in Addis Ababa “Together for cleaner air in Ethiopia”. From how Lund University presented itself, and how I presented air quality work in Arba Minch, there is a mutual interest in cooperation on the field of air pollution. While the MOU is phrased in general terms, air pollution will be the initial field of cooperation.
With help of Buro Blauw B.V., a PM2.5 reference measurement instrument has arrived in Arba Minch: a Leckel Low Volume Sampler (LVS).
Leckel Low Volume Sampler: reference instrument for PM sampling
The LVS is a NEN-12341 certified instrument for sampling PM2.5. It is the first of its kind in Ethiopia. With a constant flowrate of 2.3 m3/hour, it draws air through a filter. PM2.5 is captured by the filter. By weighing the filter weight before and after the measurement, the precise amount of PM2.5 in the sampled air volume is known. I can use this instrument to validate (and calibrate) PM2.5 low-cost sensor systems.
Until recently, these journals did not have DOI registration. I came across the Crossref GEM program, and through this program Crossref has provided Arba Minch University with DOI registration capacities for free. Through DOI registration, articles published in these journals will be found more easily through platforms like Google Scholar, which can lead to more citations and higher scientific impact.
[UPDATED] Two of my articles are published in the EJWST, and thanks to Crossref now have permanent DOI links:
Evaluation of three low-cost particulate matter (PM2.5 sensors for ambient and high exposure conditions in Arba Minch, Ethiopia: https://doi.org/10.59122/134080d
Roadside PM2.5 concentrations measured with low-cost sensors and student science in Arba Minch, Ethiopia: https://doi.org/10.59122/15519k8
For the 10 participants of a pilot study, personal exposures to Carbon Monoxide (CO) and PM2.5 concentrations exceed guideline values. You can read more about these measurements on the project page.
Guideline values
The World Health Organization (WHO) advises a PM2.5 guideline of 25 μg/m3 as 24-hour average (source), while Ethiopia uses a guideline value of 65 μg/m3 as 24-hour average (Guideline Ambient Environment Standards for Ethiopia, 2003).
For CO, guideline values are given at shorter time average periods, as health effects from CO can be more direct. Both the WHO and Ethiopia use guideline values at averaging periods of 15 minutes, 30 minutes, 1 hour and 8 hours of respectively 90, 50, 25 and 10 PPM.
Measured CO exposure
During the 24-hour measurements, peaks up to 400 PPM were measured. The figures show the measured CO concentration as boxplots for each of the participants, without and with values outside the whiskers.
CO concentrations, without data outside whiskers. Whiskers extend to 1.5 * (Q3-Q1).
CO concentrations, with data outside whiskers. Whiskers extend to 1.5 * (Q3-Q1).
24-hour average concentrations are below 6 PPM, and for all participants 75% of all data is lower than 5 PPM. There are however peak concentrations of sometimes up to 400 PPM.
To compare the measured concentrations to guideline values, we have to use 15 minute, 30 minute, 1 hour and 8 hour average concentrations. Each of these time averaging period have their own guideline value. To compare them in one graph, the below graph shows the highest average value of each of these time periods, relative to the guideline value for that averaging period. Averaging concentrations higher than 100% imply that the concentration exceeds the guideline value.
CO maximum average concentrations, relative to the respective guideline values.
Measured PM2.5 exposure
Comparing the measured PM2.5 exposure to the guideline value is more straightforward. Below figure shows the 24-hour average concentrations combined with the guideline values.
PM2.5 24-hour average concentrations.
At all households, the WHO guideline value (25 μg/m3) is exceeded. Only for the participant from household 6, the Ethiopian guideline value (65 μg/m3) is not exceeded.
However, during the 24-hour periods there is a large variability. Periods of relatively low concentrations are mixed with moments of high concentrations. Below figures show the CO and PM2.5 concentration during the whole period, for each of the participants.
Happy new year! On September 12, 2019, according to the Ethiopian calendar, a new year (2012 according to the Ethiopian calendar) has started. While in Ethiopia a change of years is not (yet) celebrated with much fireworks, it is thoroughly celebrated with delicious meals on New Year’s day. Of course, these meals will be prepared on the day before. Many of these meals are cooked on biomass fuel. This was visible on our Home Measurements location (see this project page for more information).
PM2.5 measurements
At the Home Measurements location PM2.5 is measured since August 23. The below graph shows half-hour averages between 17:00 and 2:00 (the next day) for August 23 – September 10, versus September 11 (New Year’s Eve).
On New Year's Eve the average concentration between 17:00 - 2:00 was 64 µg/m3, while on the other evenings this ranged from 10 - 39 µg/m3. Half-hour average PM2.5 concentrations were significantly higher on New Year's Eve than on any other evening (t(df:27)>=2.356, p<=0.013).
Doro Wot
The higher concentrations counted for something: on New Year's day we could enjoy delicious Doro Wot (chicken stew) at some of Arba Minch's most welcoming family homes.
The first measurement location has been installed. An IQAir AirVisual sensor is placed at the front of the house of Geertje and Jan Dirk Dingemanse in Arba Minch, Ethiopia. With its user-friendly interface, the installation consists merely out of supplying power and Wi-Fi. If electricity is available, continuous measurements of PM2.5, CO2, Temperature and Humidity are conducted and logged. The time series will give an insight in the air quality, weather conditions and availability of electricity.
A description of the measurement location and realtime measurement data can be viewed on this page. On the same page, the time series data will (irregularly) be made available for download.
