Tadesse Weyuma Bulto1. 1. Department of Environmental Management, Kotebe Metropolitan University, Addis Ababa, Ethiopia.
Abstract
Open burning of refuse is one of the key sources that causes high air pollution in Metropolitan cities. This paper identifies pollutant concentration of particulate matter (PM2.5) emission and air quality index categories with the peak hour interval on Hidar Sitaten day, and present analysis of air quality in Addis Ababa from August 2016 to November 2019. Daily records, with a 1-hour interval, of raw concentration of air pollutant and air quality index data, were obtained from the AirNow website of Addis Ababa central monitoring station. The data collected were analyzed using descriptive statistics of the mean air quality index and concentration of PM2.5. Accordingly, the study revealed that the peak hour for high pollutant concentration emission ranges between 8 pm to 11 pm hours, and the mean air quality index was more than a moderate level. Particularly, on Hidar Sitaten in 2019 at 9 pm the maximum concentration of PM2.5 was 8.6 times higher than WHO air quality guideline standard of daily allowance. The highest mean of air quality index and concentration of PM2.5 recorded was 112 and 44.2 µg/m3 on 21 November 2017, respectively, and it was found to be unhealthy for sensitive groups. This implies that the concentration of PM2.5 was harmful to people who are unusually sensitive to particulate pollution and have health problems. Therefore, public participation and strong regulations are needed on air quality management to strike a balance between a cultural practice of Hidar Sitaten and healthy air quality.
Open burning of refuse is one of the key sources that causes high air pollution in Metropolitan cities. This paper identifies pollutant concentration of particulate matter (PM2.5) emission and air quality index categories with the peak hour interval on Hidar Sitaten day, and present analysis of air quality in Addis Ababa from August 2016 to November 2019. Daily records, with a 1-hour interval, of raw concentration of air pollutant and air quality index data, were obtained from the AirNow website of Addis Ababa central monitoring station. The data collected were analyzed using descriptive statistics of the mean air quality index and concentration of PM2.5. Accordingly, the study revealed that the peak hour for high pollutant concentration emission ranges between 8 pm to 11 pm hours, and the mean air quality index was more than a moderate level. Particularly, on Hidar Sitaten in 2019 at 9 pm the maximum concentration of PM2.5 was 8.6 times higher than WHO air quality guideline standard of daily allowance. The highest mean of air quality index and concentration of PM2.5 recorded was 112 and 44.2 µg/m3 on 21 November 2017, respectively, and it was found to be unhealthy for sensitive groups. This implies that the concentration of PM2.5 was harmful to people who are unusually sensitive to particulate pollution and have health problems. Therefore, public participation and strong regulations are needed on air quality management to strike a balance between a cultural practice of Hidar Sitaten and healthy air quality.
Air pollution has been a major concern throughout the world, and ambient air
pollution is the leading environmental health risk factor worldwide.[1-3] Air pollutants are various
chemicals diffused into the atmosphere from both natural and anthropogenic sources
that change the composition of atmospheres and affect the biotic and abiotic
environment.[1,2]
Open burning, emission of air pollutants from vehicles, industries, domestic
sources, and natural sources are the source of air pollutants. A high amount of air
pollutant in the ambient air was reported to affect the health of the population.
Thus, air pollution has always been an issue when it comes to the health of the
world.[4,5] It is a key
global risk with the WHO estimating 8 million people a year dying prematurely from
breathing polluted air.[6] The quality of the air on respiration is more important for cities such as
İstanbul, having the busiest traffic flow and the highest population in Turkey.[7]Air pollutants can be transported from one region to another under the influence of
the transboundary movement of air mass,[8] and the biggest environmental health challenges confronting humanity.[9] The effect of regional pollution transport is much greater in countries with
a very high population density.[10] The outdoor and indoor air pollution is directly linked with pneumonia and
other respiratory diseases that account for almost one in 10 under-5 deaths, making
air pollution one of the leading dangers to children’s health.[11] Likewise, exposure to airborne fine PM2.5 carries substantial
health risks, particularly for younger children.[12] The time variability and long term trends of PM2.5 at various
regional background sites across Europe are studied and interpreted in the work.[13] Unhealthy air quality can harm human health and the environment as well as property.[14]Anthropogenic activities have high potential environmental and human health impacts.[15] Due to rampant industrialized growth, anthropogenic emissions of various
gaseous emissions and particulate matter rise.[16] It is an invisible and foremost cause of some of the most common human health challenges,[9] PM2.5 is a primary air pollutant, widely reported as important for
public health especially for respiratory problems.[17] It is currently one of the main concerns on a global scale for its adverse
effects on human health, environment, and climate.[18] On the other hand, fine particles are the smallest particles (those 2.5
micrometers or less in diameter) are called “fine” particles.[19] Currently, in some countries, there are traditional practices of open burning
of refuses, waste, and other municipal solid waste. Average source contributions to
PM2.5 indicate that biomass burning and motor vehicle emissions are
the predominant sources of PM2.5 across all sites in Auckland.[20] Open waste burning contributes to a large percentage of global
PM2.5 emissions with an estimated 10 million tons per year.[21] According to a study conducted by Park et al,[22] open burning was the main agent of air pollution and cause major health
difficulties for children and pregnant women and also the potential sources of
non-point emission.Air quality in Africa has remained a relatively under-researched field. Most of the
African population is dependent on biomass for cooking and heating with most of the
combustion happening in low-efficiency stoves in unvented kitchens.[23] However, air quality is closely related to quality of life. Air pollution
forecasting plays a vital role in air pollution warnings and controlling.[24] Clean air is the foremost requirement to sustain the healthy lives of
humankind. Human beings need a regular supply of food and water and an essentially
continuous supply of air. The requirements for air and water are relatively constant
(10-20 m3 and 1-2 L per day, respectively).[25] That all people should have free access to air and water of acceptable
quality is a fundamental human right.[25] Effective air quality management and planning use observational air pollutant
data to not only assess air quality conditions but to also evaluate the impact of
air quality control measures.[26]As Addis Ababa grows both economically and spatially air pollution from vehicle
emissions, open burning of waste, and other sources has become an increasing health
concern in the metropolitan area. The residents traditionally collect waste from
households like refuses, plastics, papers, and other waste materials gathered and
set alight each year on Hidar12 of the Ethiopian calendar and the date was locally
called Hidar Sitaten. This implies that the concentration of PM2.5 was
harmful to people who are unusually sensitive to particulate pollution and have
health problems. Thus, this paper intends to show the impact of the traditional
practice: Hidar Sitaten, on air quality of Addis Ababa implicate its public health
importance. Therefore, awareness creation for community, public participation, and
strong regulations are needed on air quality management to prohibit open burning of
refuse during Hidar Sitaten day.
Study design and methods
Study area
Ethiopia has a wide range of altitudes, from 100 m below sea level on the
Northeastern border to more than 4000 m above sea level in the country’s
mountain ranges.[27] Addis Ababa is located on the central highlands of Ethiopia in the middle
of Oromia region with the absolute location of nearly 09°01′48″N latitude and
38°44′24″E longitudes (Figure
1). There are 10 sub-cities with about 116 districts. The city has
seen a strong annual growth rate in 3 decades and the population as of 2017 is
growing closer to 4 million. It is now estimated to be inhabited by almost 5.4
million people.[28] The city had annual rainfall of 1175.8 mm rainfall. The climate is
characterized by 3 continuous months of rainy season (June-August) and 9 months
of dry season. A relatively colder nights (“Wurch”) exists between October and January.[29]
Figure 1.
Map of study site of US. Embassy station or Addis Ababa central
monitoring station.
Map of study site of US. Embassy station or Addis Ababa central
monitoring station.
Materials and methods
Addis Ababa has 3 PM2.5 air quality monitoring stations at Black Lion
Hospital, Addis Ababa Central, and Addis Ababa International Community School which
is run by the United States Department of State in partnership with the United
States of Environmental Protection Agency (USEPA). The air quality monitoring data
from Black Lion (Geo-Health Hub) station is not publicly available. However, the US
Embassy monitors are located at the US Embassy and the Addis Ababa International
Community School, and data are available online to the community. The study used
data from Addis Ababa central monitoring (US Embassy monitoring) station of air
concentration that is available on the AirNow website. Based on Environmental
Protection Authority standards the descriptors are intended to convey information to
the public about how air quality within each category relates to public health.Accordingly, there are two criteria used for the selection of monitoring stations.
The first criterion is availability of data and valid data for more than 2 years.
The second criterion constitutes an important factor in the selection of monitoring
sites. Based on the above criteria Addis Ababa central monitoring station site was
fit the requirement for this study. Winds in Addis Ababa come primarily from East to
West and high wind speeds tend to clear out particulate matter through
dispersion.
Data gathering
Environmental Protection Authority and its federal, tribal, state, and local
partners have developed an AirNow web site to provide the public with easy
access to national air quality information. The data used in this study were
PM2.5 concentration. The hourly concentration data were
downloaded from AirNow or www.airnow.gov website of
USEPA. The real-time air quality data and forecast were essential to protect
public health in Addis Ababa. The PM2.5 was selected due to the
negative health effects related to them. Available data was collected from
AirNow website, and trend analysis was used as data extracting method to collect
data during study period August 2016 to November 2019. AirNow receives real-time
PM2.5 data from Addis Ababa central monitor and collect air
quality forecasts for Addis Ababa city. The recorded raw concentration of air
pollutants and air quality index data are taken from a registered data
monitoring station on daily bases with 1-hour intervals.PM2.5 was considered for air pollutants and trend analysis of air
quality categories. Available air quality data and information was used to
assess the current situation and identify key peak hour air pollutant and air
quality index level or categories. Particularly, data gathered on Hidar 12
according to Ethiopia calendar when there is open burning refuse. Also, air
pollution data measured by governments across the world are a public good that
can lead to transformational advances in public health when made openly available.[30]
Data pre-processing
The raw concentration of pollutant and air quality index data was downloaded
according to day, month, and year. The pre-processing of the data was done in 2
steps namely: (1) missing or invalid data; (2) valid data. The first step
requires searching the data for missing and invalid data points, which are
flagged as –999 in the raw data or put as missed or invalid. The presence of
missing data in the dataset can be caused by various factors including the
shutdown or malfunctioning of the instrument or invalid data points that appear
due to unusually high concentrations. Finally, the time intervals for the
missing days were identified and rejected. In cases where a pollutant showing
valid data percentage value less than 60% (ie, less than 5250 hours) during a
year, that pollutant in that year was excluded from further analysis.[31] Preferably, the researcher would present secondary data analyses with
available datasets of the PM2.5 from each hours, days, months, and
years from the air monitoring station. The data were analyzed by descriptive
statistical analysis such as maximum, mean, and minimum using OriginPro version
9 software.s
Air quality indexinterpretation
Air quality indices (AQI) used for local and regional air quality management in
many metro cities of the world (Table 1).[32]
Table 1.
Air Quality Index (AQI) of particulate matter emissions and their health
concerns.[33–35]
S.No
Air quality index numbers
Level of health concern (Descriptor)
Health message
Air quality index color
1
0-50
Good
None
Green
2
51-100
Moderate
Unusually sensitive people should reduce prolonged or heavy
exertion
Yellow
3
101-150
Unhealthy for sensitive groups
Sensitive groups should reduce prolonged or heavy
exertion
Orange
4
151-200
Unhealthy
Sensitive groups should avoid prolonged or heavy exertion;
general public should reduce prolonged or heavy
exertion
Red
5
201-300
Very Unhealthy
Sensitive groups should avoid all physical activity
outdoors; general public should avoid prolonged or heavy
exertion
Purple
6
301-500
Hazardous
Everyone should avoid all physical activity outdoors
Maroon
Air Quality Index (AQI) of particulate matter emissions and their health
concerns.[33-35]
Results
The summary of maximum, mean, and minimum of PM2.5 concentration values
calculated for the monitoring station considered in this study from August 2016 to
November 2019 (Table 2).
The result revealed that, the air quality index and raw concentration of pollutant
exceeded, the allowable limits according to WHO air quality guidelines
respectively.
Table 2.
Summary of air quality index and raw concentration in maximum, mean, minimum,
and standard deviation with AQI category from 2016 to 2019 intervals from
Addis Ababa central monitoring station on 21 and 22 November.
Parameter
AQI
AQI category
Raw concentration. µg/m3
Year
Maximum
68
Moderate
22
21-11-2016
Mean
49.37
Good
12.58
Minimum
28
Good
6
Stand deviation
10.93
Good
4.78
Maximum
171
Unhealthy
106
21-11-2017
Mean
112
Unhealthy for sensitive
44.17
Minimum
53
Moderate
11
Stand deviation
40.9
Moderate
29.90
Maximum
177
Unhealthy
176
21-11-2018
Mean
68.96
Moderate
23.3
Minimum
21
Good
3
Stand deviation
45.20
Good
39.05
Maximum
184
Unhealthy
215
22-11-2019
Mean
77.6
Moderate
30.625
Minimum
24
Good
4
Stand deviation
51.8
Moderate
49.21
Summary of air quality index and raw concentration in maximum, mean, minimum,
and standard deviation with AQI category from 2016 to 2019 intervals from
Addis Ababa central monitoring station on 21 and 22 November.As indicated in Table 2
below, the mean of air quality index range between 49.4 and 112. This implies that
the level of health concern with respective to air quality was: good (2016),
moderate (2018 and 2019), and unhealthy for sensitive groups (2017) during Hidar
Sitaten day. The maximum value AQI recorded were 171, 177, and 184 for 2017, 2018,
2019 respectively. The air condition was ranged from unhealthy conditions to human
health, whereas the value of AQI recorded was 68 (2016) which was moderate on Hidar
Sitaten day (21 November).According to the WHO of air quality guidelines, the standard of PM2.5 were
25 µg/m3 and 10 µg/m3, repetitively based on relation
between 24-hour and annual PM2.5 levels (Table 3).
Table 3.
Air quality standard guideline and interim targets for particulate matter
(PM2.5): 24-hour mean.[36]
S.No
24-hour mean level
PM10 (µg/m3)
PM2.5 (µg/m3)
Basis for the selected level based
1
WHO interim target 1 (IT-1)
150
75
Based on published risk coefficients from multicenter studies
and meta-analyses (about 5% increase in short-term mortality
over AQG)
2
WHO interim target 2 (IT-2)
100
50
Based on published risk coefficients from multicenter studies
and meta-analyses (about 2.5% increase in short-term mortality
over AQG)
3
WHO interim target 3 (IT-3)
75
37.5
About 1.2% increase in short-term mortality over AQG
4
WHO air quality guidelines (AQG)
50
25
Based on relation between 24-hour and annual PM levels
Air quality standard guideline and interim targets for particulate matter
(PM2.5): 24-hour mean.[36]As shown in Table 4
below, there are possible PM2.5 air quality index categories for regions
(1997 and 2006 USEPA NAAQS, and 2007 WHO air quality guidelines). Likewise, the
daily and annual allowable of PM2.5 were 25 µg/m3 and
10 µg/m3, respectively.
Table 4.
Possible PM2.5 AQI categories for region.[35]
PM2.5 Standard (µg/m3)
1997 USEPA NAAQS
2006 USEPA NAAQS
2007 WHO Guidelines
Daily
65
Daily
35
Daily
25
Annual
15
Annual
15
Annual
10
Possible PM2.5 AQI categories for region.[35]As indicated in Figure 2
below, the highest AQI recorded was 184 at 9 PM peak hour in 2019 and the lowest air
quality level recorded was 68 at 9 PM peak hour in 2016 during Hidar Sitaten day.
Whereas, the air quality index level recorded were 171 (11 PM) and 177 (8 PM) peak
hours in 2017 and 2018, respectively. The peak hours of AQI recorded were from 8 pm
to 11 PM during Hidar Sitaten days from 2017 to 2019 which shows unhealthy air
quality.
Figure 2.
Daily air quality index values in time interval of 1 hours of Hidar Sitaten
day from 2016 to 2019 of Addis Ababa central monitoring station.
Daily air quality index values in time interval of 1 hours of Hidar Sitaten
day from 2016 to 2019 of Addis Ababa central monitoring station.As shown in Figure 3 below,
the maximum recorded raw concentration of PM2.5 were 215 µg/m3
at 9 PM peak hour in 2019. On the contrary the lowest raw concentration of
PM2.5 recorded was 22 µg/m3 at 9 PM peak hour in 2016
during Hidar Sitaten day. Besides, the peak hour ranges from 7 PM to 10 PM during
Hidar Sitaten days from 2017 to 2019 and this period is unsafe for health life.
Furthermore, 9 PM was critical time of open burning refuse and the highest emission
of PM2.5 released to the environment. It was unsafe for human and
environmental health because the Environmental Protection Authority stated the
standards of daily PM2.5 was 25 µg/m3 but the result found was
beyond the standard limit. Moreover, on Hidar Sitaten (22) day in 2019 at 9 PM, the
concentration of particulate matter released was 8.6 times higher than WHO air
quality guideline standards of daily allowance. On the other hand, the emission of
PM2.5 during 2016 was found below U.S. EPA standards
(<25 µg/m3) daily.
Figure 3.
Daily raw concentration of PM2.5 in (µg/m3) values in
time interval of 1 hours of Hidar Sitaten day from 2016 to 2019 of Addis
Ababa central monitoring station.
Daily raw concentration of PM2.5 in (µg/m3) values in
time interval of 1 hours of Hidar Sitaten day from 2016 to 2019 of Addis
Ababa central monitoring station.As indicated in Figure 4
below, the highest air quality index recorded was 112 on 21 November during Hidar
Sitetan day in 2017, on the other hand the lowest of air quality index recorded was
27.48 on 23 November 2019.
Figure 4.
Trend analysis of air quality index of PM2.5 values in time
interval of Hidar Sitaten days from 2016 to 2019 of Addis Ababa central
monitoring.
Trend analysis of air quality index of PM2.5 values in time
interval of Hidar Sitaten days from 2016 to 2019 of Addis Ababa central
monitoring.As shown in Figure 5 below,
the highest recorded raw concentration of PM2.5 was
44.17 µg/m3 on 21 November or Hidar Sitetan day 2017, whereas the
lowest concentration of air pollutants recorded was 7.29 µg/m3 on 23 of
November 2019. Moreover, the recorded raw concentration of PM2.5
increased between 21 and 27 November in 2016. Likewise, the recorded raw
concentration of PM2.5 increased 20 November and 22 November 2017.
Moreover, similar trends had been observed for the same period of 2018 and 2019.
Figure 5.
Trend analysis of raw concentration of air pollutant (PM2.5)
values in time interval of Hidar Sitaten days from 2016 to 2019 of Addis
Ababa central monitoring station.
Trend analysis of raw concentration of air pollutant (PM2.5)
values in time interval of Hidar Sitaten days from 2016 to 2019 of Addis
Ababa central monitoring station.As indicated in Figure 6
below, the highest AQI recorded was 116.1 in June 2018 and the lowest AQI recorded
was 51.9 in October 2019. Almost all AQI was found to be above 50 AQI monthly, this
implies that the air quality index of Addis Ababa city ranged between moderate and
above moderate level.
Figure 6.
Trend analysis of air quality index values in time interval of months from
2016 to 2019 of Addis Ababa central monitoring station.
Trend analysis of air quality index values in time interval of months from
2016 to 2019 of Addis Ababa central monitoring station.As shown in Figure 7 below,
the highest recorded trend of PM2.5 concentration recorded was
42.3 µg/m3 in June 2018, and the lowest PM2.5
concentration of recorded was 14.3 µg/m3 in October 2019.
Figure 7.
Trend analysis of raw concentration of PM2.5 values in time
interval of months from 2016 to 2019 of Addis Ababa central monitoring
station.
Trend analysis of raw concentration of PM2.5 values in time
interval of months from 2016 to 2019 of Addis Ababa central monitoring
station.As indicted in Figure 8
below, the highest mean concentration pollutant recorded was 44.17 µg/m3
and 30.6 µg/m3 in 2017 and 2019 respectively, Oppositely the lowest mean
annual concentration of pollutants recorded were 12.58 µg/m3 and
23.3 µg/m3 in 2016 and 2018, correspondingly. The mean average of
particulate matter concentration was 27.7 µg/m3 from August 2016 to
November 2019.
Figure 8.
The mean average and the mean of PM2.5 concentration values from
2016 to 2019 on Hidar Sitaten days.
The mean average and the mean of PM2.5 concentration values from
2016 to 2019 on Hidar Sitaten days.
Discussion
This study identifying the impact of open burning refuses on air quality during Hidar
Sitaten day. Hidar Sitaten sometimes called smoking Hidar is annually practiced and
commemorated for the memory of Spanish flu cases in Ethiopia. It is very common to
observe open burning activities on Hidar Sitaten day and the resulting air pollution
in Addis Ababa city. Consequently, respiration activities were difficult, precisely
for people who have lung complications, and for health sensitive groups. As shown in
Figure 5, the maximum
PM2.5 concentration recorded was 215 µg/m3 at 9 PM in 2019
while, the lowest concentration recorded was 22 µg/m3 at 10 PM in 2016
during Hidar Sitaten days. One study conducted in Ethiopia showed that average
concentrations of PM2.5 reached as high as 280 µg/m3 for
24-hour measurements.[37] In Addis Ababa city the coffee preparers the geometric mean
(57 µg/m3) and median (72 µg/m3) contributions to an
increase in a 24-hour time-weighted average exposure were above WHO air quality guidelines.[38] Also, the air pollution level in Addis Ababa is presumed to be high due to
the prevalence of old vehicles and substandard road infrastructures.[29] For instance, in many Asia cities, PM2.5 is a major problem and
exceeding 300 µg/m3.[39] In Guangzhou City the total suspended particulate was the prominent pollutant
in the ambient air environment.[40]The concentration PM2.5 emitted increased from May month in Addis Ababa
city presented in Figure 7.
Moreover, the highest recorded concentration PM2.5 was
42.3 µg/m3 in June 2018. This may be due to the construction
activities and collection of solid waste activities enhanced during this season. Use
of low-quality fuel, topographic structure, unplanned urbanization, industrial
facilities, and traffic were enhanced the level of air pollution.[9,41] Road construction in Ethiopia
is in high demand to meet its short and long term goals in infrastructure
development programs.[42] Therefore, the rapidly increasing transport sectors together with the fast
urbanization, poorly and slowly constructing road infrastructure and the type and
quality of high sulfur-containing fuel usage are the major sources of Addis Ababa
air quality degradation.[43] A study conducted in Ghana showed that sources of air pollution in developing
country cities include transportation and industrial pollution, biomass fuel use,
and re-suspended dust from unpaved roads.[44] In Shanghai transport pathways is the potential sources of PM10.[45] Study conducted in China showed that fugitive dust deriving from construction
sites is a serious local source of PM2.5 that leads to air pollution in
cities undergoing rapid urbanization.[46] Moreover, study conducted in Nepal shown that overall average
PM2.5 concentrations and peak 1 hour CO concentrations exceeded WHO
Indoor Air Quality Guidelines.[47]AQI is used worldwide to inform the public about levels of air pollution and
associated health risks.[48] In Addis Ababa, the AQI increased between November 21 and 27 November in
2016. Likewise, the recorded AQI increased between 20 November and 22 November 2017.
Moreover, similar trends had been observed for the same period of 2018 and 2019
(Figure 4). The higher
the AQI value the higher the level of air pollution and the greater the health
concern. AQI between 51 and 100 is acceptable; however, pollution in this range may
pose a moderate health concern for a very small number of individuals as indicted
(Appendix 1). People
who are usually sensitive to particle pollution may experience respiratory symptoms.[33] When AQI values are more than 101 air quality is considered to be unhealthy.
The current AQI approach used in China is based on the maximum value of individual
pollutants and does not consider the combined health effects of exposure to multiple pollutants.[48] A study in South Western Nigeria showed that charcoal production is often
accompanied by gaseous and particulate emission into the atmosphere and
occupationally exposed workers could be affected.[49]
Table 5.
Trend analysis of status air quality index and raw concentration of air
pollutant values in time interval on months from August 2016 to November
2019 of Addis Ababa central monitoring station (Figures 6 and 7).
S.No
Air quality Index (AQI)
Month
Raw concentration in
(µg/m3)
2016
2017
2018
2019
2016
2017
2018
2019
1
N/A
59.32
88.45
59.13
January
N/A
17.49
29.98
17.33
2
N/A
62.75
65.45
55.88
February
N/A
18.63
19.23
15.22
3
N/A
61.37
79.15
61.73
March
N/A
17.64
25.31
17.79
4
N/A
66.98
69.74
64.56
April
N/A
19.81
23.07
19.92
5
N/A
76.94
84.81
61.87
May
N/A
24.94
28.19
18.16
6
N/A
105.72
116.07
96.65
June
N/A
37.36
42.79
33.45
7
N/A
107.54
98.65
N/A
July
N/A
39.22
34.45
N/A
8
100.46
83.19
87.58
83.21
August
35.67
27.39
29.65
27.74
9
94.12
96.71
71.51
87.04
September
32.93
35.83
16.58
30.02
10
67.63
73.46
55.28
51.87
October
20.20
21.59
14.30
14.47
11
68.68
69.89
53.83
58.64
November
20.71
21.33
15.31
16.89
12
65.71
72.84
62.37
N/A
December
19.62
21.97
18.10
N/A means not available data from recorded from Addis Ababa central
monitoring station study site.
There are high pollution days associated with open-burning of refuses from November
21 to November 22. From this study, the highest trend of PM2.5
concentration recorded was 44.17 µg/m3 on 21 November 2017 (Figure 5) during Hidar Sitaten
days and months. Throughout this day, the mean average concentration of
PM2.5 was 27.7 µg/m3 from 2016 to 2019. This implies that
the mean average concentration of PM2.5 released during Hidar Sitaten day
was beyond WHO air quality guidelines (25 µg/m3) per 24 hours (Figure 8). Independent studies
conducted in Bahir Dar and Hawassa cities showed that the poor urban management
strategy, fossil fuel combustion, and aged vehicles were some of the factors
responsible for the observed concentrations.[50] Moreover, the open burning of scrap (bicycle, motorcycle, car, and truck)
tyres has a large impact on the ambient air quality.[51] Similar study conducted in Thailand revealed that the percentage of waste
burned on or outside the households’ property was 53.7% of solid waste burned in
open areas.[52]Open burning of refuse is released directly into the surrounding ambient air without
being treated or filtered.[53] PM2.5 is often considered even more dangerous to human health
because of its ultrafine size.[11] It has a major health problem for both developed and developing countries. A
study in the Neighborhoods in Oslo revealed that concentration-response relation
between air pollution (nitrogen dioxide, PM10, and PM2.5) and
cause-specific mortality.[54] The adverse health effects of exposure to pollution have received relatively
little attention to the potential impact of ambient air pollution on cognitive
function in older adults of US.[55] The 24 hours PM2.5 personal exposure was highest among adult
females with a geometric mean (GM) and Geometric Standard Deviation (GSD)
concentrations of 205 µg/m3 (1.67) in Ethiopia; 177 µg/m3
(1.61 GSD) in Uganda.[56] Air pollution poses a critical threat to human health with ambient and
household air pollution identified as key health risks in India.[57]
Future work
Based on the research findings in developing countries, open refuse burning is an
under-researched area of air pollution. The main findings in this study establish a
basis for future study related to cultural practice of open burning. As found in the
literature, the major sources of fine particles include open burning, motor
vehicles, industrial processes, and other combustion processes. The researcher
recommends that future work includes additional detailed experimental measurements
on air quality analysis on Hidar Sitaten day or seasonal air quality analysis of
Addis Ababa sub-cities. Also, air quality modeling analysis that accurately reflect
the effect of PM2.5 on human health would be suitable. Further,
investigation is needed on the analysis of increased particulate matter
concentration from May to June months indicated during the study period.
Conclusion
The main finding of the study showed that the emission of PM2.5 from the
open burning of refuses was the main source of air pollution in Addis Ababa city on
Hidar Sitaten day. The highest PM2.5 concentration recorded was
215 µg/m3 on Hidar Sitaten day at 9 PM in 2019, while the highest
mean PM2.5 concentration recorded was 44.17 µg/m3 on 21
November 2017. On the other hand, the mean concentration of PM2.5
recorded was 27.7 µg/m3 on Hidar Sitaten days. This work also showed that
the mean concentration of PM2.5 on during Hidar Sitaten was higher than
the WHO air quality guideline limits from August 2016 to November 2019. High
pollution days associated with open-burning of refuses in the 21 to 22 days of
during Hidar Sitaten. Consequently, the open burning of refuses practice causes poor
air quality. This implies that the concentration of air pollutants was harmful to
people who are usually sensitive to particle pollution and have health problems.
Authors: Aaron van Donkelaar; Randall V Martin; Michael Brauer; Ralph Kahn; Robert Levy; Carolyn Verduzco; Paul J Villeneuve Journal: Environ Health Perspect Date: 2010-06 Impact factor: 9.031
Authors: S E Bartington; I Bakolis; D Devakumar; O P Kurmi; J Gulliver; G Chaube; D S Manandhar; N M Saville; A Costello; D Osrin; A L Hansell; J G Ayres Journal: Environ Pollut Date: 2016-10-01 Impact factor: 8.071