Assessment of Lead Exposure in Thohoyandou, South Africa

Jonathan O. Okonkwo () and Flora Maribe
Additional contact information
Jonathan O. Okonkwo: Technikon Pretoria
Flora Maribe: University of Venda

Environment Systems and Decisions, 2004, vol. 24, issue 3, 171-178

Abstract: Abstract Lead levels in different environmental media (soil, grass leaves, water, ceramics, pencil, paint, crayons and cosmetics) were determined to assess the major sources of lead exposure in Thohoyandou, South Africa. Soil and plant leaves were used as indicators of Pb pollution from vehicle exhaust emissions. After digestion with concentrated acids (HNO3, HCl and HClO4) Pb concentrations were determined in triplicate using a flame atomic absorption spectrometer. The mean Pb concentrations at the kerb of selected busy roads were 205.5 ± 90, 273.0 ± 90 and 312.8 ± 81 μg g−1 and 154.7 ± 67, 182.9 ± 76 and 240.6 ± 66 μg g−1 for soil and plant leaves (dry weight) respectively. These concentrations were substantially higher than the values found on soils 50 m away from the roads (97.4 ± 11 μg g−1). Pb concentrations in plants collected further away from the road (50 m) were substantially lower (71.8 ± 9.0 μg g−1). The observed levels on soil are lower than the UK critical value of 500 μg g−1 for gardens and allotments; and 2000 μg g−1 for parks and open space as well as the Canadian values for agricultural (375 μg g−1), residential (500 μg g−1 and industrial (1000 μg g−1). From these data it was clear that Pb concentrations in soil samples were substantially higher than the levels obtained for plant leaves. The Pb levels in green crayons, blue crayons, pencils (from China & Germany), were 10650 ± 75.2, 8200 ± 52.4, 1160 ± 50.2, 79 ± 10.1 μg g−1 for the inner contents; and 4870 ± 58.1, 5650 ± 55.5, 1950 ± 46.6, 60 ± 12.9 μg g−1 for the outer surface paint respectively. The ceramics showed Pb levels of 630 ± 50.3 μg g−1 (saucer) and 560 ± 32.2 μg g−1 (cup), while the inner contents and outer surface paint showed 480 ± 32.4 and 318 ± 21.2 μg g−1 of Pb respectively. Early morning tap water flush gave a Pb level of 20.6 ± 5.6 μg Pb l−1. This value is higher than the WHO and FDA maximum permissible concentrations of 10 μg l−1 and 15 μg l−1 respectively.

Keywords: lead exposure; Thohoyandou; South Africa (search for similar items in EconPapers)
Date: 2004
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://link.springer.com/10.1007/s10669-005-6051-2 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:spr:envsyd:v:24:y:2004:i:3:d:10.1007_s10669-005-6051-2

Ordering information: This journal article can be ordered from
https://www.springer.com/journal/10669

DOI: 10.1007/s10669-005-6051-2

Access Statistics for this article

More articles in Environment Systems and Decisions from Springer
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().