Mass Concentration and Elemental Constituent of Particulate Matter in Ambient Air of Two Cement Industries and Its Health Risk Analysis

Abstract

Particulate matter concentration was measured over two cement production sites in Nigeria using a gravimetric high volume air sampler and Atomic Absorption Spectroscopy (AAS) for elemental analysis. The mass concentration of SPM ranged from 7.50 µg/m3 to 303.1 µg/m3 with mean value of 157.9 µg/m3 /day in Okpella Bua cement production site and 4.4 to 283.3 µg/m³ with mean value of 103.2 µg/m³/day for Unicem cement production site, Calabar. The elemental analysis shows the presence of Zn, Pb, Ni, Mn, Cr and Cd. The heavy metals in the order of decreasing concentration are Zn> Pb> Ni > Mn> Cr> Cd: 7.84> 2.60> 2.00> 0.80> 0.76 > 0.11 (µg/m3) respectively. All the values were higher than NESREA limit except Mn in Okpella Bua site. In UNICEM Calabar site, heavy metal distribution showed Zn> Pb> Ni> Mn> Cr> Cd: 12.50> 3.00> 1.26> 0.66> 0.41> 0.14 (µg/m3), respectively. The carcinogenic risks estimated exceeded the acceptable limit for adult, workers and children. The result showed that about 106 adults and 227 children will be affected by cancer related health problem. The mean value of the hazard quotient (HQ) was 1.46 and 2.46 from Unicem and 1.76 and 2.95 from Bua cement area for chromium and lead exposure of adult and children respectively, which shows the occurrence of the non-carcinogenic health effect on both adult and children. The result of this work revealed that children have higher risk than adult due to exposure to this inhalable particulate matter.