21 February, 2024


Are Fertilizers Released In Sri Lanka “Laced With Unsafe levels” Of Lead & Cadmium? A Vehement NO

By Chandre Dharmawardana

Dr. Chandre Dharmawardana

An opposition member of parliament, Dr Harsha De Silva raised the issue of “contaminated” fertilizer stocks in the house. News reports and social media state that fertilizers “Laced with Unsafe Levels” of Lead and Cadmium have been released  in Sri Lanka. Exposure to even small amounts of these heavy metals over time, mainly through the food chain, or by smoking, cause kidney, liver, bone and neurological damage in humans, leading to a variety of chronic diseases.

According to the news reports “The SLSI had suspended the release of the TSP consignment after it found that Lead and Cadmium in the imported fertilizer were higher than the maximum levels for toxic elements based on Sri Lanka standards specifications……However, following a meeting at the Presidential Secretariat, Director Siddika Senaratne authorized the release of the consignment into the market, on a strictly conditional basis, considering the food security of the country”.

Anyone reading the news would be justifiably alarmed, as both cadmium and lead are toxic substances that should not get into the food chain even in small concentrations.  However, we point out here that the fault is not in the imported fertilizer, but in the ridiculous standards stipulated by those who wrote Sri Lanka’s standards for heavy metal residues in fertilizers.  This is a topic that I have addressed in newspaper articles as well as in technical studies [e.g., Dharma-wardana, Environmental Geochemistry and Health volume 40, pages2739–2759 (2018) ].

This report must be taken in the backdrop of news about toxins in coconut oil, as well as the attempt of a TV-media host to make the SL Standards Institute (SLSI) Director Dr. Siddika Senaratne to reveal names of companies alleged to have imported contaminated coconut oil. She quite correctly stood her ground and declined to reveal names and make public accusations. 

The Director of a scientific laboratory is not mandated to act as a public prosecutor. However, her answer showed that scientists lack media savvy and may give totally inappropriate answers that media outlets seek to create media hype. The fact that media hosts should try to destroy due process, and create “instant exposés” in an inappropriate manner show the extent of the decline in public standards of justice and fair play in the country.

However, let us use this opportunity to educate ourselves regarding toxic substances in general, and heavy meals in fertilizers, in particular. Due to lack of space, here we examine only the case of cadmium, whose Sri Lankan standards are stated in SLS-812-standard-1988, amended and re-approved in 2008. This says that a kilo of TPS fertilizer cannot contain more than 5 mg of cadmium (or 10.9 mg per kg of P2O5).  This is an absurd specification which is impossibly LOW such that there are very few mineral sources that conform to such a specification.

Let us look at this in comparison with the standards required by other countries for cadmium in fertilizer.

Country mg of Cd per kg of phosphate.

Sri Lanka  –            5

Canada –            889

Oregan, USA –  750

California  –       400

Japan  –              148

Australia  –          131

Belgium  –            90

Europen Union  –  60 → 40 → 20 (future)

Each country, and some times each state or province of a country sets its standards based on the naturally existing cadmium levels in its soil. Most parts of UK have very high cadmium levels in its soil, and so inputs of Cd via fertilizers make ittle difference. Some parts of Western Europe (e.g, Brittany, in France, or parts of Holland) have low natural levels while Belgium is as contaminated as the UK. So the European union as a whole hopes to gradually tighten its standards and move to 20 mg/kg by 2040. But Sri Lanka has already, in 1988 itself, set its Cd limit at the impossibly low value of 5 mg/kg !

Was this very low limit set already in 1988 so as to disallow every imported batch of fertilizer, so that it can be allowed only when the right pockets are filled? Did the ring of racketeers with greased palms get broken, or did it not change with the change of government, and was this the reason why this matter had to go right up to the top for the “approval” of a perfectly safe and fine fertilizer? The fertilizer has been “condemned” as being “laced with cadmium” and other heavy metals using deliberately contrived specifications ?

How clean the food you eat depends fundamentally on the cleanliness and ecology of the soil to start with. It is only secondarily dependent on the purity of fertilizers in regard to trace metals, or the presence of traces of pesticides, even though a very different hype has been developed in the media for the consumption of a public frightened for its health and ready to even believe people like Dr. Mercola or even “Dr”. Dhammika Bandara inspired by Kaali Amma.

All soils have a certain amount of naturally occurring toxins, as well as toxins from human activity, e.g, earth works, mining, farming, burning of fossil fuels or forests that cause acid rain and noxious fumes, and poor disposal of garbage.  Even organic farming, often believed to be clean and “natural”,  produces toxins similar to those in mineral fertilizers, as composting plant matter leads to the cyclic accumulation of heavy metals like cadmium and lead found naturally in the soil, and re-concentrated in plant matter used for composting.

Mineral fertilizers like triphosphate (TPS) is mined from the ground, usually from desert locations (e.g., in Morocco, Nauri Islands in New Zealand). These mineral deposits are becoming increasingly scarce and phosphates are a threatened commodity. Mineral fertilizers applied to the soil also contribute some cadmium (and other trace metals) to the soil.

Let us take an “extremely polluted sample” of fertilizer by Sri Lanka’s specification, e.g. Nauru phosphate which has some 90 mg/kg of cadmium, i.e., 15 times more than that specified by the current absurd SL standard.  We have shown (e.g., https://doi.org/10.1007/s10653-018-0140-x)

that it will still take a many centuries to modify the cadmium levels in, say, Sri Lankan soil significantly by such fertilizer additions. Hence even such a so-called “bad” fertilizer, but used in Australia and New Zealand, would be perfectly safe for use in Sri Lanka too.

Sri Lanka has a deposit of phosphate minerals at Eppawala. While it is quite high in its arsenic contamination, it has very low cadmium contamination. Some people have urged the government to exploit the Eppawala deposits. I have opposed this as the conversion of the rock phosphate to usable TPS etc., is a highly polluting process that is best done far away from human habitations – i.e., unsuitable for Sri Lanka. In any case, a local production will also cost three to ten times more than what is available in the international market. Given the increasing scarcity of phosphate, the local deposit should be regarded as a national treasure that must be conserved for future use, until cleaner nano-technological methods for mineral exploitation become available.

Hence I urge the government to change the cadmium and other heavy metal specifications used in Sri Lanka to conform to modern scientific knowledge and align its standards with values used internationally. Having looked at the level of cadmium in Sri Lankan soils, I believe that an appropriate standard for Sri Lanka is to set its upper level for cadmium to be about 100-150 mg per kg of Phosphate, instead the current absurdly low value.

*The author is currently affiliated with the National Research Council of Canada, Ottawa, and the University of Montreal. He was a past VC and Professor of Chemistry at Vidyodya/SJP university.

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Latest comments

  • 6

    Did Gota Rajapaksa use any scientific rationale to conditionally release the particular batch of fertilizer ?

    If the Cadmium limit set by SL in 1988 is impossible to achieve, haven’t we been receiving any fertiliser meeting the standard for heavy metals since 1988?

    “The WHO and the Food and Agriculture Organization (FAO) have agreed on and implemented safe exposure levels for food in the Codex Alimentarius and the European Food Safety Association is also enforcing a reduction of cadmium exposure since it is becoming increasingly dangerous for certain subpopulations who are exposed to it the most.”
    “Cadmium is a non-nutritive metal considered harmful to the environment and to humans, affecting mainly kidney and the skeleton and it’s also carcinogen by inhalation.”

    Not convinced that Dr. Chandre Dharmawardana, as physicist /chemist, is suitable to comment on health impact of cadmium on “sub-populations” nor has the integrity and ethics to make non-political judgements.

    Is the naturally occurring cadmium level in SL soil already in excess of the threshold for health impact on humans&animals? Or is there latitude to accumulate more cadmium?

    It’s a shame the author excused himself from discussing lead limits in depth.

    • 6

      Let’s look at all this in perspective. We all eat rice. A hell of a lot. It makes us fat and lazy. So productivity goes down. Expensive fertilizer is imported, for which we have no money. So, this is good for us. Like the ban on palm oil and coconut oil imports. We can go back to eating rice on Tuesday, Thursday, and Sunday. If younger readers are mystified by this, ask your grandparents. Be prepared for the forthcoming discovery that the Muslim Arabs have mixed “wanda-pethi” into petrol and diesel . Palm oil has been banned to save money, according to Bandula G . Imagine what this will do to the price of bakery items? Good people, do go buy a bull or two before this happens. The kind with four legs, of course, not the 69 lakhs of the other kind.

      • 2

        To supplement what Mr OC says, here is an article that appeared in the BMC Nephrology in 2015, for those interested in a bit of truth, from a practitioner of medicine, not a chemist: https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-015-0211-5

        Recent articles also demonstrate toxic levels of cadmium and lead in staples such as Jak (kos), and other preferred foods for our largely vegetarian rural population.

        Yes, we all eat a hell of a lot of rice, and the less affluent one is, the tendency (nay necessity), is to eat a hell of a lot more. And kos too.

        The great pity is, nothing is done to investigate the hypotheses that have been derived by eminent local scientists who drew a link between the unbridled use of chemical fertilisers starting from the 1970-s when the “Green Revolution” was promulgated, and the rapidly rising incidence of chronic kidney disease linked to heavy metals. See: https://www.sciencedirect.com/science/article/abs/pii/S0378427410014682

        • 2

          One prominent local scientist claimed Natha Deviyo told him that Arsenic caused CKD. He is now ambassador to Myanmar.

          • 2

            Yo! And another went to Geneva to lament that glyphosate causes CKDu… he also invented the abortion canard against Dr Shafi. Guess where he is now – the state minister of health, no less!!! All dressed in national costume and all!!

            It’s the reign of the kings again, so kiss goodbye to any low, odour or decency for a long while to come.

    • 6


      You are right. What is the rational for Gotabaya to involve in the release of fertiliser? If SLSI standard is wrong what will you do before releasing the fertiliser? Just change the standard, not by President but by a group of scientists. Unfortunately, what happened to those scientists who have not given clearance to the vaccine Gota got it from China been punished. This is the country which worships Gota as their God (destroyer).

  • 5

    Exactly Sugandh, why now ??? if we had such rigid laws didn’t we survive until now. How come only during Rajapaksas time it turns into an issue. There was water contamination during MR time and when people protested they got shot. I will like to see the author and his family consume the disputed food items 24 /7 and convince public.

  • 0

    Arsenic content of Eppawela phosphate is not high as claimed. It is reported to be around 3-5 ppm. Of course as Prof. Chandre says cadmium level is very low and at least ten times lower than Nauru rock phosphates.
    I do not agree that manufacturing fertiliser from Eppawela phosphate is not desirable. While TSP making is polluting, SSP manufacture is a feasible and an environmentally friendly option. This view has been expressed by many Sri Lankan scientists who have worked on the deposit and an expert team from New Zealand who did a comprehensive survey suggested SSP over TSP. Politicians who expect to make a buck by selling this to a foreign company have continuously blocked this venture. If SSP is manufactured then the cost can be brought down to half of imported TSP. We import TSP because it has 2.4 times more phosphate and considering the cost of transporting by ships. Sri Lanka is a small country where transport costs is not a major factor particularly if train is used for transport.

  • 2

    Good article. Now the human rights champions cannot allege “fertilizer genocide” against the present government.

  • 0

    Sri Lanka – 5

    Canada – 889

    Oregan, USA – 750

    California – 400

    Japan – 148

    Australia – 131

    Belgium – 90

    Europen Union – 60 → 40 → 20 (future)

    I can only laugh at this. Thank you very much for sharing this information.

  • 1

    Having taken a look at the following source (and others), the author’s presentation here is highly dubious particularly with respect to health risks and occupational exposure of Cadmium in fertilizers;

    Take a look at the Canadian Regulation;
    3.1.2 Upper limits/thresholds
    Metals limits are predicated on the maximum acceptable cumulative addition to soils over a 45 year time period. The cumulative application approach is intended to account for the persistence of metals in the environment which ultimately determines the level of contamination and long term impacts.
    The maximum acceptable metal concentration in a product (in mg metal/kg product) is calculated for each metal using the CFIA standards for maximum acceptable addition to soil and the product’s maximum recommended annual application rate.

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