Airborne Lead Exposure among Informal Sector Workers at Kamukunji “Jua Kali” Sheds in Nairobi County, Kenya

Abstract

Lead (Pb) is widely used in various industries during production processes which result in exposure among workers if proper occupational safety and health measures are not put in place. Lead is highly harmful to human health and the environment. In developed countries, strict controls and improvements in industrial methods have helped to ensure that occupational Lead poisoning is less prevalent whereas in developing countries, it remains a problem of huge dimensions especially in the informal sector. Previous research work has shown informal sector workers have elevated blood Lead levels which may be attributed to airborne exposure. This study sought to evaluate airborne Lead exposure among informal sector workers in Kamukunji, Nairobi County. Descriptive and experimental techniques were used in the study which the concentration of airborne Pb was determined from 34 sheds in Kamukunji and two control groups. Airborne Lead was collected on filters using air sampling pumps in 34 sheds where metal cutting, folding, heating, welding, soldering, grinding and painting works were being done. Two control areas with no known exposure to Lead were also sampled. In addition, questionnaires were issued to the selected shed leaders. The concentration of airborne Lead was determined using flame atomic absorption spectroscopy (FAAS). The study revealed that, 55.9% of the sampled sites had airborne Pb concentration (µg/m3) ranging from 1.45 ± 0.06 µg/m3 to 126.85 ± 20.14 µg/m3. The control and fifteen sheds representing 44.1% had airborne Pb concentration below the detectable limits (BDL). The results obtained show that all the sampling sites had airborne Pb levels within the Kenya occupational limit of 150µg/m3. However, four sheds (11.76%) had much high Lead in air LIA levels than the Permissible Exposure Limit (PEL) of 50 µg/m3 set by the US OSHA standards for general industry on a Time Weighted Average (TWA) of 8 hours. The mean airborne Pb concentrations (µg/m3) were 53.61 ± 0.60, 126.85 ± 20.14, 56.42 ± 3.05 and 117.36 ± 5.19 that were observed in sheds 6, 11, 16 and 27, respectively. From empirical perspective, 50.0% of the respondents (n= 34) had secondary education while 29.4% had primary education. The study revealed that 61.8%) of the respondents were unaware of Pb exposure and related adverse effects. Seventy-one percent (71.0%) of the respondents did not undergo medical checkups. Eighty-five (85.0%) of those who visited the hospital had cough, chest problems and blood pressure. All respondents lacked adequate protective means against exposure to Pb at their workplace. Observations made were that food production was done within the sites, which could contribute to ingestion as another route of Lead intake. It can thus be concluded that most respondents in this study were exposed to Pb levels associated with working activities hence the need for safe work practice, training programs, awareness programs among other occupational safety and health strategies to protect them from these exposures.