Short-Term Exposure Assessments and Elemental Composition of Particulate Matter (Pm10) of Urban Indoor and Outdoor Air Pollution at Different Microenvironments in Addis Ababa, Ethiopia
No Thumbnail Available
Date
2018-08-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Nowadays air pollution is a major health hazard in the daily life of humans in the world. Estimating personal exposure to air pollution is a crucial thing in identifying high-risk population and identifying controlling strategies. Because of the difficulty of measuring full personal exposure to air pollution patterns of individuals, it is better to measure it at different homogenous microenvironments (MEs) linked with their activities. In this study, short-term exposure and elemental composition analysis of indoor and outdoor air pollutions were carried out at different MEs while doing different activities. A total of 45 households were selected from Akaki Kality, Gulelle and Arada sub-city, Addis Ababa, Ethiopia for the short-term exposure assessment to indoor air pollution. Whereas, ten sub-cities were selected (three sampling points from each) for the exposure assessment to outdoor air pollution during commuting time. The short-term exposure assessment to particulate matter (PMs) in the air samples of different particle size (PM1, PM2.5, PM4, PM7, PM10 and TSP, total suspended particles) and total volatile organic compounds (TVOCs) under different domestic activities (during baking Injera, cooking Wot), while sitting at the living room and during commuting time were assessed. PMs and TVOCs were measured by a simple and portable sensor called A ROCET531S and AEROQUAL series 500, respectively. The elemental composition of PM10 was analyzed by using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES).
The level of TVOCs and PMs have been measured during the baking of Ethiopian’s traditional staple food Injera (a flatbread mostly made from Teff flour and baked upon a circular griddle), using electric, improved and traditional stoves. The geometric mean (GOM) of PMs pollutant for the wet and dry seasons during baking Injera using clean, improved, traditional stoves were ranged: 37-235; 72.8-462; 50.3-591 μg m-3 and 10.8-119; 23.6-265; 36.4-728 μg m-3, respectively. iv
The GOM of TVOCs for the wet and dry seasons using clean, improved, traditional stoves found were: 1553, 2234, 4421 and 845, 1214, 2662 μg m-3, respectively. The users of clean and improved stoves instead of the traditional stove can reduce the level of exposure to PMs and TVOCs exposure in the range of 12.3-81.7%, which is depending on both the type of pollutant and stove type. Similarly, depending on the type of pollutant, clean stove can reduce the level of exposure to PMs and TVOCs by a minimum of 26.5% and maximum of 51.7% as compared to improved stove.
The GOM of TVOCs and PMs were also measured during cooking of the most widely consumed Ethiopian traditional dish sauces (Wot, in Amharic) using different types of fuels namely electricity, charcoal and kerosene. The GOM of PMs for the wet and dry seasons using electricity, kerosene, charcoal fuel were ranged: 11.4-109, 14-134, 21.2-190 μg m-3 and 7.68-203, 10.5-198, 15.6-284 μg m-3, respectively. The GOM of TVOCs during the wet and dry seasons using electricity, kerosene and charcoal found were: 350, 706, 1200 and 394, 555, 812 μg m-3, respectively. Using of electricity and kerosene fuels instead of charcoal fuel for cooking Wot can reduce the level of exposure to PMs and TVOCs by a minimum of 28.9% and maximum of 62.9%, which is depending on both the pollutant type and fuel type. Similarly, electricity fuel can reduce the level of exposure to PMs and TVOCs by a minimum of 5.23% and maximum of 40.6% as compared to kerosene fuel depending on the type of pollutant.
The GOM of PMs and TVOCs at the living room (when cooking activities were not performed) were also measured and the result of PMs found were ranged: 5.68-99.0 μg m-3, whereas the TVOCs was found 289 μg m-3.
The short-term exposure assessment to outdoor air pollution was also carried out by selecting the sampling points at the main roadside, and the sampling period during the commuting time when v
traffic congestion and taxi queue were expected to be high. The GOM of PMs and TVOCs found in the ten sub-cities were ranged 6.79-496 and 220-439 μg m-3, respectively.
The health risk due to exposure to PM2.5, PM10 and TSP either individual (based on hazard quotient calculation, HQ) or cumulatively (based on hazard index calculation, HI) were performed according to the United States Environmental Protection Agency prescription at each of the selected MEs. Thus, the individual or cumulative PM2.5, PM10 and TSP exposure during baking Injera using any of the stove types (traditional, improved and clean stove) is below one which indicates baking activity only may not have a likelihood to induce health problems. The individual exposure of PM2.5, PM10 and TSP during coking Wot using electricity, kerosene and charcoal fuels also may not have a likelihood to induce health problems, except PM10. Whereas PM10 at the individual level can pose non-carcinogenic health problems during cooking Wot using the charcoal fuel. However, the cumulative effect might have a likelihood to pose a health impact problems in any of the three fuels types. Similarly, the health risk assessment at the living room was also calculated that both individual and cumulative exposure to PM2.5, PM10 and TSP at this ME may not have a likelihood to induce any health problems. In addition, both the individual and cumulative exposure to PM10 and cumulative exposure to PM2.5 and TSP at roadside may have a likelihood to induce health problems to a person who is exposed at least 8 h per day.
Furthermore, trace elements (Fe, Cd, As, Cr, Pb, B, Ni, Co, Sn, Cu and Zn) bound in PM10 at kitchen ME during baking of Injera using improved, traditional stove and clean stoves were found in the range BLD-632, BLD-0.499 and BLD-0.078 μg m-3, respectively. Whereas their concentration at kitchen ME during cooking of Wot using electricity, kerosene and charcoal fuels were found in the range 0.001-0.058, 0.003-0.175 and 0.001-0.109 μg m-3, respectively. Similarly, vi
their concentration at the living room and at the roadsides MEs were ranged: 0.001-0.026 and 0.013-0.444 μg m-3, respectively.
The carcinogenic and non-carcinogenic risk assessment due to elementals in PM10 exposure were also performed at all selected MEs. Hence, Mn, As and Cd are the major elemental pollutants found that have a prominent share in inducing a health problems to exposed children and adults at roadside MEs. Similarly, a person baking Injera (using any of clean, improved and traditional stoves), cooking Wot (using any of the electricity, charcoal and kerosene fuels) and sitting at living room MEs for an extended period did not have health risk due to measured elements in PM10.
Description
Keywords
Fuel Type, Charcoal, Kerosene, Electricity, Sauces, Wot, Cook Stove, Biomass, Particulate Matter, Injera, Commuter Exposure, Elemental Composition, Health Risk Assessment, Vehicles Sources, Inductively Coupled Plasma-Optical Emission Spectroscopy, Addis Ababa, Ethiopia