What is the significance of this index? Add reference paper if possible.
Dear Shankhadeep,
Igeo = log 2 ([sediment]/ 1.5* [reference sample]).
The factor 1.5 is introduced to minimize the effect of possible variations in the background values which might be attributed to lithologic variations in the sediments. According to Bradl the reference samples are As: 13, Cd: 0.3, Co: 20, Cr: 100, Pb: 20 and Cu: 50 µg/g.
With my best regards
Prof. Bachir ACHOUR
Dear Chakraborty Sir,
An index of geo-accumulation (Igeo) was originally defined by Müller (1969), and can be calculated by the following equation:
Igeo = log2 [Cs / (1.5*Cb)]
Cs is the measured concentration of the examined heavy metal in sample
1.5 is the background matrix correction due to terrigenous effects or the factor 1.5 is introduced to minimize the effect of the possible variations in the background
Cb is the geochemical background concentration or reference value of the metal or the background value of heavy metals in the uncontaminated sample.
Index of Geo-accumulation (Igeo)*
Value Pollution category
Igeo ≤ 0 = Unpolluted
0
Sir,
I am afraid I should warn you. Igeo is not good for sediments irrespective of how frequently it is used for such rocks. Whenever sediment grain size varies, concentrations of all elements vary accordingly and thus any "safety factor" like 1.5 (as mentioned by previous sirs who answered your question) cannot help. Much better is to use local enrichment factor with 1) well-chosen reference element and 2) genuine local reference sediment (without the phenomenon you intend to address by Igeo). So, the crucial question is to what purpose you want to use Igeo. It is more tricky than it is assumed by 99% those who use it. If you want to discuss this topic, kindly write me [email protected]
Good luck in your work
TMG
you can find here my paper which contain all the statistcal analysis of pollution for heavy metals in water, sediment, total suspended matter and also for human risk
and you will find how to cacultae IGeo:
https://www.researchgate.net/publication/309463664_Environmental_Assessment_of_Heavy_Metal_Pollution_and_Human_Health_Risk?_iepl%5BviewId%5D=MlkrHMoAYt2rCTQFSWozrGov&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BinteractionType%5D=publicationTitle
regards,
Article Environmental Assessment of Heavy Metal Pollution and Human ...
Dear Prof. Shankhadeep Chakraborty
Kindly find a small paper published in Environmental Geochemistry and Health .I will appreciate if you could help me with your comments.
Article Heavy metals contamination in urban surface soils of Medak p...
Is Geochemical background concentration same for all country/ region? And how to calculate Geochemical background concentration?
Need specific answer/ paper/ link..
To assess the ecological risks of heavy metals in soil different methods have been widely used, geoaccumulation index (Igeo) .please refer the following attached file.
@ Md Leion Hassan
You can find a very nice discussion on the geochemical background in the article:
Matschullat, J., Ottenstein, R. & Reimann, C. Geochemical background – can we calculate it?. Environmental Geology 39, 990–1000 (2000). https://doi.org/10.1007/s002549900084
Can the measured concentration (Cn)be taken from XRF or we take the concentration from the exchangeable phase in order to calculate the Igeo?
Good day, total concentrations (such as XRF analyses) must be used in Igeo. TMG
Hi,
It may also be good to include leaching tests in your experiments to understand the relative mobilities of target pollutants. Pollution indices will give you a measure of how polluted the samples are, but they cannot show if the pollutants are mobile (bioavailable) or not. You can check out the attached paper about ASGM impacted soils if you're interested.
Good luck!
Best regards,
Carlito
Thank you Tomas Matys Grygar and Carlito Baltazar Tabelin for your answers, much appreciated!
Can anyone tell me if geoaccumulation index is used only for soil/sediment or can it be used for dust as well?
Maisha Binte Sultan Yes! The geoaccumulation index can be used for dust, as the dust is a composite of soil particles. You can find literature on this...
Can someone calculate the Geo accumulation index for physicochemical parameters of water? If yes how?
- Badges
- Science topic
- Similar topics
- Biological Science
- Biochemistry
- Biochemical Techniques
- Analytical Chemistry
- pH