RESULTS OF URINE AND BLOOD FROM RESIDENTS AROUND THE COPPER SMELTER COMPLEX, TSUMEB, NAMIBIA: AN EXAMPLE OF ANTHROPOGENIC CONTAMINATION.

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1 RESULTS OF URINE AND BLOOD FROM RESIDENTS AROUND THE COPPER SMELTER COMPLEX, TSUMEB, NAMIBIA: AN EXAMPLE OF ANTHROPOGENIC CONTAMINATION. B.S. Mapani 1, R. L.Hahn 2, R. Ellmies 3, G. Schneider 4, N. Mwananawa 3, S. Uugulu 1 and William Amaambo 3 1. University of Namibia, Geology Department, Private Bag 13301, Windhoek, Namibiabmapani@unam.na. 2. German Research Foundation, Bonn, Germany. 3. Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany. 4. Geological Survey of Namibia, 1-Aviation Road, Windhoek, Namibia. ABSTRACT The Tsumeb area has been established to contain contamined soil samples around the area west of the smelter complex. The results of a medical test programme of Tsumeb residents are presented. A total of 154 urine samples and 148 blood samples were collected with the assistance of Tsumeb hospital. The blood samples were analysed for lead and cadmium by AAS and the morning urine samples for arsenic and cadmium by ICP-OES. More than a fifth of the investigated residents of Tsumeb showed lead concentrations in blood exceeding the WHO guideline value (10 μg/dl). The highest values for lead in blood (maximum value 55 μg/dl) exceed the WHO limit by more than five times. Statistics show that every sixth surveyed person exceeds the WHO guideline value for arsenic concentration in urine. The highest detected arsenic concentration in urine of 443 μg/l exceeds the WHO limit of 50 μg/l by almost nine times. Nearly all cadmium values in blood were below the detection limit of 0.1 μg/l. The creatinine-adjusted cadmium concentrations in urine with the exception of two cases did not exceed the guideline values. The analytical results correlate for lead in blood and arsenic in urine. Residents with anomalous high concentrations are mainly confined to Tsumeb-Nomtsoub suburb to the west and the industrial zone to the north of the town. Residents of the Transnamib Hostel just opposite the old smelter show the most critical values. The anomalous values could be attributed to inhalation of contaminated dust as well as the contact with contaminated soil and

2 the consumption of contaminated crops as these parts of Tsumeb are more exposed to dust fallout from the smelter complex than the central and southern parts of the town. Introduction Exposure of humans to metals has been known for a long time, since the time of Agricola (1494), when he documented the effects of dust on mine workers in the Carpathian Mines, where most of them died at an early age. Several authors have documented such exposure to industrial pollution, for example; Alonso et al. (2001) document the exposure of a population living near an industrial site with contaminated soils. Tsumeb (Figure 1) has been a mining and smelting district for the past 115 years. Mining ceased in 1999, but smelting of copper ores continues to this day. Over this period, technologies have changed and conditions of ore processing have become much better. However the legacy of the former years of smelting of both Pb and Cu ores has led to severe contamination oft he Tsumeb area. The most affected area ist he Nomstoub area to the northwest of the town (Figure 2). An exposure assessment of the town s residents has not been carried out in recent years. The objective of the study is to document the extent and distribution of the toxic heavy metals lead and cadmium and the metalloid arsenic in blood and urine samples of representative individuals of the town.

3 Figures 1 and 2. On the left ist he plan oft he Tsumeb town. On the left in figure 2 is the contamination plume of soils as a result of smelting ores. Materials and Methods The study area, shown in figures 1 and 2. The area consists of mainly two zones (Figure 1). The area, east and south of the CBD (City Business District) and the western part of the CBD, mainly the Nomtsoub township (Figure 1). In figure 2 is shown the results of the detailed sampling campaign done by the Geological Survey of Namibia (GSN, 2008). The result in figure 2 was the basis for the selection of the subjects for sampling. Individuals from the Nomtsoub township, which has highly contaminated soils in which the concentrations are all above the Canadian Guideline Values (Canadian Council of Ministers of the Environment, 2006) for domestic habitation. Blood samples of 10 ml were taken by trained personnel at the Tsumeb Private Hospital (nurses and doctors). The samples were analysed for lead and cadmium by atomic absorption spectrometry (AAS). The 20 ml urine samples were collected in the morning and analysed for arsenic and cadmium by inductively coupled plasma spectrometry (ICP) at the laboratory of Ongopolo Mining and Processing Ltd., and for creatinine by the laboratory of the Tsumeb Private Hospital.

4 Results In the first measurement campaign (22 25 April 2007), 89 blood samples and 113 urine samples were collected from 113 study subjects. 66 of them were adults (>18y of age, 30 males and 36 females) and 47 were children (19 males and 28 females). In the second measurement campaign (29 May 1 June 2007), we collected additional blood samples (N=37) and urine samples (N=38) from 38 other volunteers. These volunteers were mainly adults (N=28; 16 men and 12 women). Of the 10 children, 8 were boys and 2 were girls. Additionally, in the second campaign, we took blood and urine samples from study volunteers who showed anomalous blood lead values in the first collection period. 24 volunteers (16 adults and 8 children) provided 23 blood samples and 5 urine samples. The results are shown in Tables 1 and 2. Table 1. Comparison of lead in blood (PbB) results of first and second test campaign Sample No. Lead in Blood (µg/dl) April 22 to 25, 2007 May 29 to June 1, 2007 U200-U123 Male Adult 20 4 U201-U124 Female Adult 11 3 U202-U128 Male Adult 12 6 U203-U129 Male Adult U204-U130 Male Adult U205-U131 Male Adult U206-U132 Female Adult U207-U135 Male Adult U208-U137 Male Adult 35 4 U209-U139 Male Adult 24 1 U210-U140 Male Adult 14 3 U211-U83 Male child 19 8 U216-U85 Female Child U217-U86 Male Child U219-U96 Male Adult 17 6 U220-U101 Female Adult U223-U113 Female Child U225-U24 Female Adult 11 6 U226-U28 Male Adult 13 7

5 U227-U34 Female Child 11 8 U228-U35 Male Child U229-U38 Male Child U230-U39 Male Child 12 7 Table 2. Comparison of arsenic in urine results for both sampling campaigns (shading: values exceeding the guideline of 50 µg/l) Sample Gender First survey Second survey Residence/Working Place No. As in Urine (µg/l) As in Urine (µg/l) U204- Male Transnamib Holdings Ltd. U130 U206- Female Transnamib Holdings Ltd. U132 U207- Male Transnamib Holdings Ltd. U135 U209- Male Transnamib Holdings Ltd. U138 U212-U81 Female Nomtsoub (Opawa School) U213-U82 Male/Boy Nomtsoub (Opawa School) U230-U39 Male/Boy Nomtsoub (St. Francis Sch.) U231-U42 Female Nomtsoub Primary School U233-U55 Male/Boy Nomtsoub Primary School U234-U10 Female\Girl Tsumeb Gymnasium Conclusions The medical tests conducted in Tsumeb showed that more than a fifth of the 148 investigated persons have lead concentrations in blood (PbB) exceeding the WHO guideline value of 10 µg/dl. The PbB values of six residents exceed the guideline by 100%. 16 % of 144 individuals show arsenic concentrations in urine (AsU) exceeding international guideline values (WHO 50 μg/l). In addition, the analysis of two urine samples exceeds the guideline value for cadmium. In general, anomalous high PbB correlate with anomalous high AsU. They are confined to Nomtsoub Township and adjacent industrial zone to the north with the highest individual values

6 for PbB (55 µg/dl) and for AsU (443 µg/l). The anomalous high PbB and AsU occur in areas with severely contaminated soils (GSN, 2006; GSN 2007). This study revealed generally high lead in blood and arsenic in urine concentrations for residents of Tsumeb in areas which have been prone to severe dust fall out from the old and new smelter sites. Acknowledgements The authors would like to express their sincere thanks to the - German Research Foundation which generously financed the medical research, and - Mr Hans Nolte, Managing Director of Namibia Customs Smelter (Weatherly International PLC) for the open and constructive discussions and the generous financing of the analyses of the heavy metals in blood as well as urine. Furthermore, the authors are much obliged to all the institutions and individuals who contributed to the success of the project: - Mr. Isai Nekundi and Mrs. Miriam Muteka of Namibia Customs Smelter. - Mrs. Antje Goeltje and Mr. J.H. Hagström (Laboratory) of the Tsumeb Private Hospital - The Municipality of Tsumeb - The Oshikoto Regional Councillor - The Director of Health Services The second phase of soil sampling and vegetation sampling was surpported by the SIDA- UNESCO project (503RAF2000) on abandoned mines in Sub-Saharan African countries. References Alonso, E., Cambra, K., and Martinez, T. (2001): Lead and cadmium exposure from contaminated soil among residents of a farm area near an industrial site. Archives of Environmental Health: An International Journal, 56, Canadian Environmental Council of Ministers of the Environment (1999): Soil Quality Guidelines for the Protection of Environmental and Human Health, updated WHO (1981): Arsenic. Environmental Health Criteria 18, 174 p. - Geneva.