Measurements of Carcinogenic Pollutants at Cement Industries in Nigeria and Neighbouring Countries
The source identification of Polychlorinated Dibenzo-p-Dioxins (PCDDS) and Polychlorinated Dibenzo-p-Furans (PCDFS) in West Africa has been the most difficult problem to tackle due to the unavailability of the facility to analyse the samples and high cost of sampling equipment. This study is based only on the determination of the PCDDS/PCDFS at cement industries in Nigeria, Cameroun and Benin Republic. The sampling adopted the gravimetric (method) principle for extractive source analysis using Paul Gothe Bochum stack sampler and PCDDS/PCDFS traps from Concept Life Sciences Laboratory in the UK. The traps were exposed using the standard guidelines and transported back to the same laboratory for analysis in the UK. The parameters recorded during PCDDS/PCDFS sampling are stack temperature, ambient temperature, pressure, flow rate and moisture content at isokinetic mode. The PCDDS/PCDFS results from different cement industries are: Nigeria (Plant A = 0.0209 ng/TEQ/Nm3; Plant B = 0.0316 ng/TEQ/Nm3), Cameroun (Plant C = 0.0062 ng/TEQ/Nm3; Plant D = 0.0143ng/TEQ/Nm3) and Benin Republic (Plant E = 0.0101 ng/TEQ/Nm3). All the results recorded are below Nigerian emission standards and international emission standards. By comparing the standards, the disparity between Nigeria and other international countries is high while other neighbouring countries do not have the PCDDS/PCDFS standard. This might be due to typographical errors or the paucity of data for PCDDS/PCDFS from different sources to review the standards. Based on the nature of PCDDS/PCDFS on humans and ecosystems, the major concern is long-range transmission and accumulation in the food chain and animals. From this study, it is observed that the determination of PCDDS/PCDFS from other sources will be a great achievement for the implementation of reduction mechanism strategies. It is being recommended that the Nigerian Government should carry out a national emission inventory along with neighbouring countries. Also, existing standards and regulations on open burning, industries, mobiles and dumpsites should be strictly implemented.