An assessment of the emission of combustible gases in developing countries requires reliable analytical realtime monitors that can rapidly screen them with minimal handling. Considering the expensive nature of monitor...An assessment of the emission of combustible gases in developing countries requires reliable analytical realtime monitors that can rapidly screen them with minimal handling. Considering the expensive nature of monitoring environmental pollutants, chemical sensors are expected to play a pivotal role in measuring and recording environmental data. The Drager X am 5000 was used to report emission levels of combustible gases in this study, namely;nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) at traffic and practising waste dumpsite in Freetown, the main city of Sierra Leone. Hourly average values for the three pollutants were recorded in the morning, afternoon and evening periods, respectively. The range of values were 18 - 76 ppb for NO2, 211 - 506 ppb for SO2 and 11 - 14 ppm for CO at traffic site;and 6 - 16 ppb for NO2, 118 - 276 ppb for SO2 and 8 - 15 ppm for CO at the dumpsite, respectively. There were significantly high hourly variations for NO2 and SO2 at the traffic site and for CO and SO2 at the dumpsite. Evidence of peak values showed emission levels that were considered dangerous for human exposure. This pilot study revealed that combustible gases released in certain areas of the capital city are a concern for both public health officials and environmental advocates.展开更多
文摘An assessment of the emission of combustible gases in developing countries requires reliable analytical realtime monitors that can rapidly screen them with minimal handling. Considering the expensive nature of monitoring environmental pollutants, chemical sensors are expected to play a pivotal role in measuring and recording environmental data. The Drager X am 5000 was used to report emission levels of combustible gases in this study, namely;nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) at traffic and practising waste dumpsite in Freetown, the main city of Sierra Leone. Hourly average values for the three pollutants were recorded in the morning, afternoon and evening periods, respectively. The range of values were 18 - 76 ppb for NO2, 211 - 506 ppb for SO2 and 11 - 14 ppm for CO at traffic site;and 6 - 16 ppb for NO2, 118 - 276 ppb for SO2 and 8 - 15 ppm for CO at the dumpsite, respectively. There were significantly high hourly variations for NO2 and SO2 at the traffic site and for CO and SO2 at the dumpsite. Evidence of peak values showed emission levels that were considered dangerous for human exposure. This pilot study revealed that combustible gases released in certain areas of the capital city are a concern for both public health officials and environmental advocates.
