Chandre Dharmawardana, National Research Council of Canada

According to a news report (Island, 2-11-20), Mr. Chinthaka Rajapaksa, who is said to be the moderator of an organization known as  the Movement for Land and Agricultural Reform (MONLAR)” claims  a high probability that the fertilizer currently released to the market were of low quality and high in heavy metals, as the National Fertiliser Secretariat had stopped testing samples at local labs”.

It seems that these labs are currently non-functional because of the Covid crisis, and so foreign labs are used. Testing has not stopped. The non-analysis and lack of testing of compost fertilizers are  ignored by MONLAR as they  are tacitly supported by MONLAR!  Here I will show that even if one of the world’s worst rock phosphates, e.g, Nauru phosphate from New Zealand,  containing very high amounts of heavy metals (occurring naturally)  were imported, it will still have NO TOXIC effect if applied to Sri Lankan soils for agricultural purposes. This is based on the research I have published in peer-reviewed journals. For instance, Mr. Rajapaksa should consult  my publication in Environmental Geophysics and Health, August 2018  https://doi.org/10.1007/s10653-018-0140-x where a detailed discussion is found. Here we will explain all this more simply in the following.

However,  first we must look at the political agenda of MONLAR itself. Although I am not aware of the current political  strategy of MONLAR in detail, I personally knew some of the initial founders of this movement. They were Marxist militants who decided to launch a movement  to capture and control the peasant farmers and convert them into a revolutionary political force”.  A key tactic was to rouse the farmers into opposing  big capitalist agricultural multi-nationals” and their genetically modified (GM)  products and seeds. Imported fertilizers sold by capitalist multi-nationals” were also targeted. The opposition to GM products and high-yielding hybrid seeds led them to  back traditional seed varieties”. These yield about a fifth of the harvest from modern hybrid seeds created by the rice scientists at Bathalagoda and other research Institutes. They were the real unsung heroes who have kept the exponentially increased population of the nation away from famine since World War II.  A return to traditional seeds will mean a return to shortages, famines, and re-importing milchaard haal”.

But MONLAR and other backers of traditional seeds” and compost fertilizers etc., are either mesmerized by false claims and fake science, or are cynically using them to further their political agendas. They want to negate the good work our scientists. Even the Minister Pathirana seems to have  been tragically mislead into presenting a motion for traditional seeds” in place of hybrids (Island, 02-11-20). The motion states that this Parliament resolves …(to).. educate the public on the nutritious value of the traditional, local rice varieties available in the Sri Lankan market at present, of the new rice varieties consumed at present, and of the varieties of rice that should be consumed by people with various diseases, and also to provide facilities for farmers to cultivate those varieties of paddy.” So the minister wants to cure diseases with rice, while 30% of  kids come hungry to school! Unfortunately, it is the minister who has to be educated. This may be a case where the minster’s scientific and medical advisors dare not contradict the minster and put him right!

The opposition to  imported fertilizer led these groups to support the use of compost whose composition and quality are never subject to analysis. But MONLAR rushes to claim that imported triple phosphate is full of heavy-metal toxins profiting from a lapse in local testing due to an epidemic! This cry had already found resonance with the Natha Deviyo” group led by Ms. Senanayake of Hela-suvaya” together with  Dr. Nalin de Silva, then at the Kelaniya Science faculty, and Ven. Rathana, then an MP from the JHU. They claimed that many illnesses, e.g., Kidney diseases in the Rajarata, are caused by arsenic and other toxins in imported fertilizers and herbicides, even though these claims were, and are now found to be completely contrary to exhaustive investigations by several independent research groups. For instance, strong evidence now suggest that the Rajarata Kidney disease is contracted by people who drink water from wells containing excessive amounts of fluoride and hard water, both of geological origin (See: Imbulana et al., Science of the Total Environment, 2020, https://doi.org/10.1016/j.scitotenv.2020.140716 and references therein ); in contrast,  those who drink water from agricultural canals, rivers and tanks carrying fertilizer  runoff are free of the disease!

Why do I say that even if one of the  cheapest and worst available” mineral phosphates, e.g., Nauru phosphate were used in agriculture, it will have no effect on our health? Let us consider this in detail.

Cadmium (Cd), arsenic (As) and lead (Pb) are some of the dangerous metal toxins found in minerals.

We will take the example of Cd, as the discussion for other toxins follows the same lines. Nauru rock phosphate contains some 90 mg of cadmium per kg of phosphate, where as a more expensive phosphate fertilizer may contain less than 20 mg of cadmium per kg of fertilizer. European green” activists who are much like their counterparts in Sri Lanka have clamored for lowered amounts of cadmium (and other such toxins) in fertilizers imported to Europe.

Let us consider that we imported the Nauru phosphate that has been used in New Zealand, and containing some 90 mg of Cd per kilo of rock phosphate. A farmer usually applies some 30 to 60 kg of phosphate fertilizer per hectare of land in planting rice, depending on the soil.  The fertilizer is ploughed into about a depth of  about 8-12 inches (20-30 cm). Taking a figure of 30 cm depth in a hectare of land, the 60 kg of fertilizer containing  60 x 90 mg (i.e., 0.54 g) of cadmium are dispersed in a soil volume of 3000 cubic meters, or about 3900 metric tonnes of soil of density 1.3 g/litre. So,  0.54 g of cadmium are dispersed in this volume of soil, increasing the soil cadmium concentration by a mere 1.38 nanograms/kg, i.e., 1.38 parts per quadrillion. This is an utterly minuscule amount as the ambient level of cadmium in the soil may be as high as 0.4 mg/kg even in virgin forest soil (Chandrajith and Dissanayake  2012), and this is similar to values known for  European soils.  NO LEACHING what ever was assume even in estimating the 1.38 parts per quadrillion, and of course this is not true. The monsoonal rains can wash off many many times more than the 1.38 part per quadrillion.

So, when MONLAR claims that substandard fertilizer probably containing dangerous levels of toxins is being imported to Sri Lanka and that no chemical analysis is done, this is just fear-mongering and nothing else. The calculation that I presented needs only a knowledge of simple arithmetic and MONLAR, claiming expertise in agriculture should be able to do this before raising alarms.

This does not mean that EXCESS USE of fertilizer does not pollute the environment. The excess phosphate fertilizer gets washed off into the aquatic ecosystem via rivers and canals and create Algal blooms and weed growth. They de-oxygenate the water and asphyxiate aquatic organisms. The seasonal increase in phosphate levels in the Rajarata tanks is given in Table 1 of a research publication that I authored with other collaborators in  Environmental Geochemistry and Health: Volume 37, Issue 2 (2015). This applies to macroscopic components like phosphates contained in the fertilizer, but NOT to the microscopic components (trace amounts) like Cd, As, and Pb. The metal toxins largely come into the environment from other sources (e.g., mining, burning of fossil fuels, acid rain, burning garbage, smoking cigarettes etc)  as discussed in relevant publications.

Chandre Dharmawardana, National Research Council of Canada.