Investigation into Trace Elements in PM10 from the Baking of Injera Using Clean, Improved and Traditional Stoves: Emission and Health Risk Assessment

Abstract

Particulate matter with aerodynamic diameters < 10 µm (PM10) emitted during the baking of Ethiopian’s traditional staple food Injera (a flatbread mostly made from Teff flour and baked upon a circular griddle) was collected for analysis. Emissions of inhalable particles from three types of stoves, clean, improved, and traditional stoves, were tested to determine the elemental composition and to assess the short-term exposure and health risk of the particles in the indoor microenvironment. The PM10 was collected with the help of a portable sampling unit with multi-fraction dust samplers, and its elemental composition was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentration of PM10 pollutant using clean, improved, traditional stoves were 139, 259 and 571 µg m−3, respectively. The concentrations of trace elements (Fe, Cd, As, Cr, Pb, B, Ni, Co, Sn, Cu and Zn) bound in PM10 during the use of improved, traditional stove and clean stoves ranged from below detection limit (BDL) to 632, BDL to 0.499 and BDL to 0.078 µg m−3, respectively. The carcinogenic and non-carcinogenic risks of the exposed person to trace elements bound in PM10 were assessed according to the US Environmental Protection Agency prescription. Although the US National Quality Standard is 150 µg/m3 for 24 h, the results showed that the likelihood that an average person has either carcinogenic or non-carcinogenic health impacts by using any of the three stoves over a lifetime at a frequency of twice a week is very low. However, the PM10 contribution of wood-burning stoves to the total daily exposure is high.