Dear Mr. Sahoo,

According to Russian ecological legislation maximum permissible concentrations of these metals in soil are following, mg/kg:

Pb – 6,0 (mobile fraction) and 32,0 (total concentration)

Cr (+3) – 6,0 (mobile fraction)

Cr (+6) – 0,05 (mobile fraction)

Ni – 4,0 (mobile fraction)

Co – 5,0 (mobile fraction)

Zn – 23,0 (mobile fraction)

Cu – 3,0 (mobile fraction)

With best wishes

Bakhtiyor

check this link

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/69261/pb13297-soil-strategy-090910.pdf

WHO. 2007. Joint FAO/WHO Expert standards program codex Alimentation Commission. Geneva, Switzerland. Available online http://www.who.int [Accessed 10/09/2012].

Awashthi, S. K. (2000). Prevention of Food Adulteration Act No. 37 of 1954. Central and State rules as amended for 1999 (3rd ed.). New Delhi: Ashoka Law House.

I express my thanks to all for your answer but I am yet to get my answer what I am looking for. 

maximum tolerable levels proposed by joint FAO/WHO Expert committee on food additives (2007), in mg/kg dry soil

Pb, - 250-500

Cr,- 3-6

Ni,- 75-150

Co,- 

Zn- 300-600

Cu- 135-270

Dear S. K. Tripathi, I have already mentioned in my question what I am looking for. 

Dear Avinash Kumar, 

Thank you for your kind information. Can you please share with me the details of the reference (or it's link)  you have mentioned  so that I will go through it? 

I have given you above.

Dear Sahoo,

Please go through attached link. you should read once for better performance.

hope this would be valuable for your work.

Regards

Dear Mr. Sahoo,

I am attaching the copy of the original Document with the list of Maximum permissible (tolerable as you said) concentrations of some pollutants in soil (mg/kg of air dry weight). Sorry that it is in Russian. It can be translated to English as: Enactment of Supreme State Sanitary Doctor (Inspector) of Russian Federation from 23.01.2006 “On introduction into the force of hygienic norms GN 2.1.7.2041-06”.

At the same time I would like to emphasize that it is impossible to establish unique soil pollution standards for all countries. These standards are very dependent on regional geochemical particularities and vary widely. Therefore probably you could not find WHO standards.

Besides that I am in a great doubt that given by Avinash Kumar data for Pb – 250-500 and Ni – 75-150, Zn – 300-600 and Cu – 135-270 are correct. E.g. Cu is highly toxic metal, especially if it in mobile fraction and given concentration is most probably having chronicle toxic impact on soil micro flora. You have to check these figures for correctness.

With best wishes

Bakhtiyor

Dear Bakhtiyor Sir, 

Thank you for your information. In addition I have checked Mr. Avinash Kumar data and found it's correct for the Indian context. Once again thank you for sharing your information.

The following article provides the regulatory standards for heavy metals in agricultural soils of several countries.

Heavy metal contamination of soils:sources,indicators and assessment.  He,Z. et al. Journal of Environmental Indicators,9:17-18,2015

Scholar.uwindsor.ca./cgi/viewconent.cgi?article=10208&context...

open access:www.environmentalindicators.net

Dear Himadri,

Maximum permissible concentrations of heavy metals in agricultural soils of European countries as reported by Kabata-Pendias and Pendias (2001) are listed below:

Cd (cadmium) 5 mg/kg, Co (cobalt) 50 mg/kg, Cr (chromium) 100 mg/kg, Cu (copper) 100 mg/kg, Ni (nickel) 100 mg/kg, Pb (lead) 100 mg/kg, and Zn (zinc) 300 mg/kg.

Reference: Kabata-Pendias A. and Pendias H. (2001) Trace elements in soils and plants. 3rd edition. CRC Press, Boca Raton, Florida, 413 pp.

I also attach PDF copy of an article on this subject. Hope you find this input interesting and useful.

Respected Kundu Sir, 

I express my sincere thanks for sharing your information. It is really a great help for me. 

In my country Venezuela there are two differents criteria. First to agricultural purpose which depends on plant uptake and tolerance physiological. Second to irrigation water, ambiental purpose, Pb limited 0,01 mg/L, Na 200 mg/L, Cu 20 mg/L (Standard Methods for Water and Lixiaviations).

Your question leads to a plethora of open problems in soil sciences - and straight on  answer would be misleading (unfortunately). There are lots of tables of tolerable, permissible, precautionary levels, etc., all for total concentrations in agricultural soils. On the one hand, few tables present values modified according the soil character (clay / silt / sand), which makes quite a difference for plant availability. On the other hand, as pointed out by Bakhtiyor Karimov most important is the concentration of the mobile fraction.  However, the question remains: what is mobile and under which conditions – and how to define mobility. The German Federal Soil Protection Act and Ordinance (1999) recommends the use of ammonium nitrate (1 m) to define plant availability, whereas the US EPA defines a TCLP (Toxicity Characteristic Leaching Procedure) which uses acetic acid; and there are many more suggestions. All these methods are batch procedures, which give no insight into the mobilization characteristics of soil constituents, i.e. information on possible plant availability.  An advanced assessment of availability can be derived from a sequential elution method as published by Tessier et al. (1979); since then the method was modified and adapted to different substrates several times. By its main structure the method yields an assessment of bonding form portions, five of which can be mobilized according the environment conditions (adsorbed phase, carbonates, bound to Fe-Mn-Ox-Hydrox., bound to Fe- Ox-Hydrox., sulfides/humic substances). Finally a stable portion is defined (silicates, stable oxides), which is not available. By this an assessment of plant availability is more realistic than knowledge of total values or assessments based on batch experiments, both of which can be quite misleading. I agree that the approach of sequential elution requires much more care, skills in sampling and analysis, and analytical equipment; but under the aspect of ever-increasing soil use and soil pollution this approach should be worth while.

Kind regards

D. Zachmann

The allowed limits for agricultural soils, in use here are (mg/kg)

As :20-  Cd:3-  B: 2-  Zn: 60*-  Cu: 150 - Cr: 750- Hg: 0- Ni: 150- Pb: 375-  Se: 2

* take note that Zn is a vital nutrient and so very low values are worse than the limit. value .}

I express my sincere thanks to all the Scientists and Researchers for sharing their valuable information. 

Mr.Himadri,you may also see the following link.

https://www.researchgate.net/post/What_is_the_best_method_for_assessing_and_monitoring_the_heavy_metal_polluted_soils/1

As epressed by many researchers, this is not an easy question to answer. However, apart from the suggestions already made, there other lists with suggestions (guidelines) regarding this issue, for example:

1. The New Dutch List,

2. ICRCL 59-83 (Interdepartmental Committee on the Redevelopment of

Contaminated Land), 

3. The Kelly Indices, etc.

One must be very carefull befor jumping into cocnlusions, as many parameters are important (i.e., dissolution techniques, analytical techniques, type of soil etc.).

Best luck with your research.

Himadri,

You can find additional screening values of various derivations (such as US background levels, older Dutch standards, and US EPA Eco-Soil Screening Levels) in the SQuiRT cards [attached ]. Keep in mind these cards have not been updated since 2008. In comparison though, I agree with Bakhtiyor  that the values he referenced seem too high.

The "best" answer to your question though truly depends on the objective of your study. If you are merely in a screening level assessment, many of the sources others have provided here would suffice as comparative screening guidelines. If your ultimate goal is a more robust risk assessment of a specific area, the factors that influence form and availability of trace elements in soil, which others have also referred to, cannot be ignored. The next step beyond a screening level assessment would depend on your resources and the scale of your study.

Cheers,

Mike

Thank you Mike, 

This study is about a preliminary assessment of a specific area. 

Dear Himadri

First of all you must know objective of your research

Second, which are parameters and features of "your" soils

Comparative assessment of content of some elements can be provide for specific conditions of a particular territory (and goes without soils).

The tolerance limit itself may not have sense. Better way, in my guess, is calculation local background content of heave metals (trace elements).

Kind regards. Yuriy

 I endorse the suggestion of Dr.Yurij to determine the background levels of heavy metals  in dominant soil /soils in a specific area to know build up if any of  the contaminated heavy metals in that area.

According to FAO 2007

the upper limit for pb in soil is 100 mg / kg

While Ca is about 3 mg/kg

But still need some detials about the critical values of these metals in plant????

Cu (0.86 mgL-1), Zn (0.30 mgL-1) Mn (0.21 mgL-1), Ni (0.12 mgL-1), Co (0.11 mgL-1) and Cr (0.10 mgL-1)

see the attachment file i think is useful