Die inkorporering van biomerkers in die assessering van die ekologiese risiko van chemiese bodemkontaminante

Reinecke, A. J. ; Reinecke, S. A. ; Maboeta, M. S. ; Odendaal, J. P. ; Snyman, R. (2007)

CITATION: Reinecke, A. J. et al. 2007. Die inkorporering van biomerkers in die assessering van die ekologiese risiko van chemiese bodemkontaminante. South African Journal of Science and Technology, 26(2):120-137, doi:10.4102/satnt.v26i2.129.

The original publication is available at http://www.satnt.ac.za

Article

Soil is an important but complex natural resource which is increasingly used as sink for chemicals. The monitoring of soil quality and the assessment of risks posed by contaminants have become crucial. This study deals with the potential use of biomarkers in the monitoring of soils and the assessment of risk resulting from contamination. Apart from an overview of the existing literature on biomarkers, the results of various of our field experiments in South African soils are discussed. Biomarkers may have potential in the assessment of risk because they can indicate at an early stage that exposure has taken place and that a toxic response has been initiated. It is therefore expected that early biomarkers will play an increasing role as diagnostic tools for determining exposure to chemicals and the resulting effects. They may have predictive value that can assist in the prevention or minimising of risks. The aim of this study was to investigate the possibilities of using our results on biomarker responses of soil dwelling organisms to predict changes at higher organisational levels (which may have ecological implications). Our recent experimental results on the evaluation of various biomarkers in both the laboratory and the field are interpreted and placed in perspective within the broader framework of response biology. The aim was further to contribute to the development and application of biomarkers in regulatory risk assessment schemes of soils. This critical review of our own and recent literature on biomarkers in ecotoxicology leads to the conclusion that biomarkers can, under certain conditions, be useful tools in risk assessment. Clear relationships between contamination loads in soil organisms and certain biomarker responses were determined in woodlice, earthworms and terrestrial snails. Clear correlations were also established in field experiments between biomarker responses and changes at the population level. This indicated that, in spite of the fact that direct mechanistic links are still not clarified, biomarkers may have the potential to provide early indications of forthcoming changes at higher organisational levels. Ways are proposed in which biomarkers could be used in the future in risk assessment schemes of soils and future research directions are suggested.

Grond is ’n belangrike, maar komplekse natuurlike hulpbron wat toenemend as reservoir van chemiese stowwe dien. Die monitering van grondkwaliteit en die assessering van die risiko’s wat kontaminasie meebring, het van kardinale belang geword. Hierdie studie handel oor die moontlike aanwending van biomerkers in die monitering van gronde en in die bepaling van die risiko’s wat kontaminasie inhou. Afgesien van ’n oorsig oor die bestaande vakliteratuur oor biomerkers, word die resultate van verskeie veldproewe waarin biomerkers gebruik is en wat afsonderlik uitgevoer is in Suid-Afrikaanse gronde, geïntegreerd weergegee. Bepaling van blootstelling sowel as effekte is belangrik in risiko-assessering. Daarom het biomerkers potensiaal in die assesseringsproses omdat dit vroeg reeds kan aantoon of blootstelling wel plaasgevind het en of ’n toksiese respons geïnisieer is. Gevolglik word verwag dat vroeë biomerkers ’n toenemend belangrike rol sal speel as diagnostiese hulpmiddels vir die bepaling van blootstelling aan chemiese stowwe en die daaropvolgende effekte. Die vraag word aangespreek of dit voorspellingsmoontlikhede bied wat kan help om risiko’s te voorkom of te minimaliseer. Die doel van hierdie studie was om die moontlikhede te ondersoek om ons resultate oor biomerkerresponse van verskillende grondlewende organismes te gebruik om veranderinge op hoër organisatoriese vlakke (wat ekologiese implikasies mag inhou), te voorspel. Ons onlangse eksperimentele resultate oor die evaluering van verskeie biomerkers in sowel die veld as die laboratorium word geïnterpreteer en in perspektief geplaas met die breë konseptuele raamwerk van responsbiologie. Die oogmerk was voorts om ’n bydrae te lewer tot die ontwikkeling en aanwending van biomerkers in regulatoriese risiko-assesseringskemas van gronde. Hierdie kritiese oorsig van eie bevindinge en die onlangse literatuur, lei tot die slotsom dat, hoewel heelwat ontwikkeling nog gedoen moet word, hierdie hulpmiddels onder bepaalde voorwaardes van groot nut kan wees in risiko-assessering. Duidelike verbande tussen kontaminasievlakke in grondorganismes en bepaalde biomerkerresponse is vasgestel vir houtluise, erdwurms en landslakke. Duidelike korrelasies is ook in veldeksperimente gevind tussen biomerkerresponse en veranderinge op bevolkingsvlak. Hoewel direkte, meganistiese verbande tussen biomerkerresponse en latere veranderinge op hoër organisatoriese vlakke nog ontbreek, dui die resultate daarop dat biomerkers wel die potensiaal het om as vroeë aanduiders te kan dien van sodanige veranderinge. ’n Wyse word voorgestel waarvolgens biomerkers in toekomstige risiko-assesseringskemas vir gronde ingesluit kan word en verdere navorsingsdoelwitte word uitgewys.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/19558
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