Inorganic Lead Poisoning in the Printing Industry

Abstract

This study was carried out at Khartoum University Press (KUP) and AI-Sudan Al-Hadith Printing Press (AAPP), to assess the magnitude of inorganic lead poisoning and the degree of exposure among workers. A questionnaire was designed to find out the workers history and any clinical symptoms associated with lead poisoning. The questionnaire revealed that fatigue and respiratory problems were the main complaints in both sites. Blood and urine samples were collected from workers at the working site. Heat stress parameters and air samples were also recorded. Blood samples were analyzed for lead concentration, haemoglobin, and red blood cell count. While urine samples were screend first for coproporphyrin excretion level and then for lead concentration. At KUP coproporphyrin values were found to range from 125 to 58.59 micro g/l.While at AAPP values ranged from 0.00 to 40.70 micro g/l which is below the range (120 micro g/l) recommended by WHO. Lead in urine at KUP was found to be in the range of 12 to 77.4 microg/l00 ml with a mean of 23.94 ± 14.73 while at AAPP values were in the range from 27.65 to 52.48 microg/l 00 ml with a mean of 39.56 ± 4.88.When comparing the mean values of the sampled workers, t -test showed a significant difference (p< 0.005), reflecting a difference due to the work environment. Lead content in blood of workers at KUP had a mean of 21.06 ± 10.19 and ranged from 8.53 to 38.85 micro g/l00 ml. While at AAPP values were in the range from 4.85 to 83.5 micro g/l00 ml with Cl mean of 24.52 ± 14.47. The t-test showed no significant difference (p< 0.05) between the two means. At KUP haemoglobin had a mean value of 83.31 % which is very high but at AAPP the mean value was 56.46% indicating an overall possibility of lead poisoning. Workers at both sites had a low Red Blood Cell count which may be an indication of lead poisoning. Lead in blood samples exceeded the biological standard at both sites showing an occupational overexposure. Lead content in air samples exceeded the average allowable concentrations at all locations which is an indication that the workers are exposed to high lead concentrations. Thermal measurements revealed that the wet bulb-globe temperature (WBGT) index exceeded the threshold level which also confirms the fact that workers are at a high risk of lead poisoning. According to physical and biological parameters, workers at both sites were found to be exposed to the risk of lead poisoning which needs to be controlled, treated and the environmental factors should he modified for a cleaner and healthier environment .