By Emeritus Professor Upali Samarajeewa International expert on food safety Courtesy The Island

In the list of words most feared by many Sri Lankans, Arsenic stands among the top10. Historically, arsenic was a rat poison. This potential of arsenic was illegally employed later to get rid of unwanted friends and even spouses by some of the humans. However, arsenic had positive use and reputation as a health care agent. It is reported that Hippocrates used arsenic sulfide in the form of natural crystalline minerals, namely realgar and orpiment, to treat ulcers. Later, the arsenic containing minerals were used in making creams to remove unwanted hair in the human body. Since then, arsenides and arsenic salts in the form of creams for external application have been in use for centuries, in treatment of ulcers and syphilis. In the 1700s solutions of arsenic trioxide in potassium bicarbonate has been prescribed to treat asthma, chorea, psoriasis, anemia, and leukemia among several other health ailments. Some drugs containing arsenic have been prescribed to be inhaled as vapour, injected, or administered intravenously in the 19th century. Though the International Agency for Cancer Research classified arsenic in its pure form, and certain arsenic compound as a human carcinogens, Food and Drugs Administration of the USA approved the use of injectable arsenic trioxide for human treatment for relapsed acute promyelocytic leukemia. It may be considered an exceptional condition, but arsenic compounds do not deserve a total taboo without understanding their effects on the human body under each situation, beneficial or harmful. Arsenic trioxide was withdrawn from human treatment in 1950. There is evidence today on the effects of long- term exposure of humans to inorganic arsenic through food, water, or air leading to increased risk on bladder, lung, and skin cancers.

WHO records

The World Health Organization records on incidence of cancer in Sri Lanka for 2020 shows 7% lung cancer, 2.1% bladder cancer and 0.4% skin cancer, out of the total annual cancer cases. Almost all incidences of lung cancer are among males predominantly associated with smoking. The same percentage distribution of all cancers was visible in records over the previous 20 years, with fluctuations only in incidence of lung cancer. Arsenophobia was created in Sri Lanka in relation to the chronic kidney disease of unknown origin, identified as CKDU. The global literature on kidney diseases do not consider arsenic as a crucial factor in chronic kidney diseases similar to CKDU. Sri Lanka is not the only country having chronic kidney disease of this nature. There are parallels in Chronic interstitial nephritis in agricultural communities” (CINAC) in El Salvador and Nicaragua. CINAC is also described as Mesoamerican nephropathy (MeN) in several other central and south American countries, mostly along the Pacific coastline. Scientific studies in the USA on the above chronic kidney diseases have identified relationship with a few pesticides. Some of the pesticides were banned in Sri Lanka decades back, and one still in use though to a limited extent. The studies in the USA have not been able to recognise links between arsenic or other heavy metals with the chronic kidney diseases described above.

Arsenic was used as an ingredient in weedicides and wood preservatives in the past. Registration of companies producing pesticides containing inorganic arsenic were cancelled in 1988 in the developed world. Sri Lanka does not permit the use of pesticides containing inorganic arsenic. If there is violation of this condition, there is a way to handle it rather than banning everything. The registrar of pesticides operates an accredited testing laboratory for arsenic and other heavy metals in pesticides. If law makers possess doubts on arsenic entering our food system through pesticides, what is needed simply is to provide more facilities and activate the office of the registrar of pesticides to bring in necessary controls. That is the scientific mechanism used in the developed countries to maintain food safety in the production chains. Pesticides came into existence because it had a role in agriculture. Replacing pesticides needs to identify a scientifically equivalent substitute. The World has not been successful in it. What is needed is to implement checks and controls at the appropriate levels and locations.

Cause of CKDU

If arsenic is the cause of CKDU, it should enter the humans through our main staple rice and drinking water. In Bangladesh and West Bengal, heavy and unacceptable concentrations of arsenic were reported in rice and water leading to major investigations by the United Nation bodies responsible for food and health. In the two locations the symptoms due to arsenic were quite different from the symptoms of CKDU reported in Sri Lanka. The writer, having examined 50 peer reviewed research publications and scientific reviews of acceptable quality by Sri Lankan and foreign scientists, found the arsenic concentrations in rice and water in Sri Lanka are far below the globally implemented tolerance limits of 0.2 milligrams per kilogram for rice, and 10 micrograms per litre for water. The average concentrations of arsenic in Sri Lankan rice are less than 25% of the tolerance limits for rice. The concentrations of arsenic in drinking water are less than 15% of the tolerance limit. The perused studies cover a period from 2005 to 2021. The scientific evidence has clearly proved that the arsenic concentrations in our foods pose no risk to health to Sri Lankans.

There are occasional reports on rejection of imported and locally produced canned fish due to presence of total arsenic. Total arsenic consists of inorganic arsenic and organic arsenic. Organic arsenic is present mainly in prawns and other crustaceans. Some fish carry lower concentrations of organic arsenic than crustaceans. Foods containing almost non-toxic organic arsenic carries no health risk unlike highly toxic inorganic arsenic in foods. Organic arsenic moves unabsorbed through our digestive system, getting excreted fast. Arsenic may be present in the environment and food in different inorganic forms and almost non-toxic organic forms. Main organic arsenic compound in fish is arsenobetaine. Arsenobetaine is of no toxicological concern. The issue of arsenic in fish need to be understood from a deep scientific angle before implementing controls.

Regulations

The regulations implemented by our standards and food regulatory authorities apply 0.2 milligrams per kilogram as the limit for total arsenic concentration in all foods. Regulations unfortunately takes no recognition on the toxicity difference between the organic and inorganic forms of arsenic. Arsenic appears in different forms food. Of them the inorganic forms are the culprit with high toxicity. The organic forms are of negligible toxicity. Our authorities need to distinguish between inorganic arsenic (which is 50-90% of total arsenic in rice) and organic arsenic which is approximately 95% of the total arsenic in fish. This raises an important question as to whether application of the general limit of 0.2 milligrams per kilogram of total arsenic to canned fish, which contains less than around 5% of the toxic inorganic arsenic. Interpretation of regulations needs much more scientific thinking than blind interpretations. Research scientists understand that there is no world free of arsenic and other toxic compounds. Arguing for zero arsenic or any other harmful ingredients in food and water is an indication of ignorance on basic principles of risk based regulatory approach. The tolerance limits are fixed for each and every harmful agent is to ensure food security meeting only required level of food safety.

Food safety

In arriving at decisions on food safety, the authorities consider the possible outcome of their decisions on food security of the country. First, there should be food for people to eat and live. Then comes the levels of risks associated with presence of harmful constituents. A good example is presented in the research by the USA scientists on problems linked to arsenic in rice. The mean arsenic concentrations expressed in milligrams per kilogram of rice in USA was 0.193 for white rice and 0.205 for brown rice against the regulatory limit of 0.200. The USA arsenic concentrations are at least 5 times higher than the values reported for rice in Sri Lanka. Applying the values to daily exposure of Americans consuming rice in 2-3 meals a day, it was postulated that they could reach high-risk level leading to bladder and lung cancer of the more vulnerable populations, especially the elderly and pregnant mothers. It was shown, using models, that reducing the tolerance level from current 0.200 to 0.100, would result in reduction of rice availability in the American market by a factor up to 90%, creating a food security risk. The study also postulated a reduction of regulatory limit from current 0.200 to 0.075 would bring down the food safety risk due to arsenic in rice from 11% to 79%. The regulations are maintained therefore, at 0.200 to ensure rice availability. The arsenic concentrations in Sri Lankan rice (approximately 0.04 milligrams per kilogram), is still far below the hypothetical USA limit of 0.075 limit, worked as a theoretical possibility. With all the scientific evidence, USA did not reduce the limit to 0.100. The scientific evidence clearly suggests that the ‘arsenophobia’ created in the minds of Sri Lankans is a hoax. It is continued even today by vociferous persons with scientific ignorance.

Arsenic enters food chain from soil or irrigation water. The earth crust is not free of arsenic. The crust contains 1.8 milligrams of arsenic per kilogram of soil on the average. It could take the range from 1-40. Arsenic concentrations above five milligrams per kilogram of soil make soils unsuitable for cultivation. The arsenic content in agricultural soils in Sri Lanka average around one milligram per kilogram, implying no food safety threat through local rice. The arsenic toxicity in rice occurred in West Bengal and Bangladesh due to high arsenic concentrations rising to the order of 15 milligrams per kilogram in their soils. Their irrigation water contained 10-fold higher arsenic than the permitted limit, leading to serious health problems. Sri Lankan situation is not at all comparable with the situation in West Bengal and Bangladesh. Unfortunately, we import rice from time to time from Bangladesh and other countries having arsenic contaminations.

If the food chain in a country gets contaminated with arsenic or any other toxic entities, they get detected in the exports at the foreign border check points, resulting in rejections and notifications. Information on global trade does not show instances of Sri Lanka tea or any other food getting rejected due to arsenic, or other heavy metals, or unpermitted pesticide residues.

It speaks on the Sri Lankan agricultural system was managed. Unfortunately, there are pseudo-scientists with no understanding on agriculture and food production, all out to create doubts in the minds of public.

This brings in the question as to where Sri Lanka went wrong in its science. It started with a vociferous student reading for a postgraduate degree in a university in Sri Lanka, working totally outside the specialty of his first degree in 2011. In desperation, he went to a soothsayer in a ‘Devalaya’ reputed to utter to the gullible people, under trans state of the mind. She was given some soil from Rajarata. She yelled asan asan” perhaps asking him to listen. The student came back and started testing for arsenic using equipment of inadequate sophistication, applying unrefined test methods, ultimately innovating” non-existent arsenic in rice. Tabloid media were fast to capture information. The ‘innovation’ was further supported by a media-oriented professor, who excelled in many fields other than his trained expertise.

The Island

carried an article around May 2011 under the title Arsenic in Rice: Playing God”. The article highlighted the seriousness of statements arrived at without following basic principles of analytical chemistry and risk assessments, misleading the public. The materials released to the press have not gone through scientific scrutiny and was obviously questionable. The ‘arsenophobia’ next entered the august house with appearance of a reddish colour in Kohila” curry in the meals served to members of the Parliament. The reddish colour is a common biological phenomenon on foods exposed to oxygen from air under certain preparation practices. It was October 2012 and The Island carried a note titled Arsenic and cyanide everywhere”. The news on innovation of so-called arsenic in rice was next carried to the ears of the first citizen of the country at that time. He with his usual smile and tact said, I eat rice three meals a day.” The message was clear to the student. Later the first citizen warned the media professor on the dangers Sri Lanka would face in our export trade, with this kind of utterances through the media. At that time there was already a shipment containing rice from Sri Lanka which was detained at a port in Turkey pending testing for arsenic. However, the stock did not get rejected as no arsenic was detected. The arsenophobia did not get marketed with the next first citizen either. Later the innovator of arsenic story reached the august house with a promise to provide Better Health for Rajarata.” Arsenic is forgotten at least in the public eyes.

The baton was taken up by another relay team consisting of a priest, medical professional and an academic (sanga-weda-guru) expecting blessings from the highest level in the country. Unfortunately, the struggle ended up with farmers and labourers (govi-kamkaru) facing the problem. Indications are that the country would have to bear the outcome of arsenophobia for many months, if not years to come with inadequate food at exorbitant prices. No country in the world has stopped use of synthetic fertilizer in food production. European Union countries maintain extremely high levels of food safety in the world. They have decided to reach 25% organic food production by 2030 very cautiously. Canada produce food only during the warm six months of the year. They export 68% of the produce. In the Canadian Agriculture policy food production for export is a high priority. They apply scientifically controlled methods in use of agrochemicals. It is said that Canada was the major supplier of red dhal to Sri Lanka in certain years.

Leaders need to listen to scientific facts generated through careful experimenting and scholarly thinking. Mature scientists do not rush foolishly to take risks; politicians only see short term benefits. The prosperity of a country lies in well discussed decisions arrived through scientific knowledge, and not based on ad hoc findings of half-baked pseudoscientists. The l strength of India lies on the initiative to apply science in its policies immediately after independence by the Prime Minister Jawaharlal Nehru. The writer had the opportunity on two occasions to participate the Annual Indian Science Congress. On both occasions, the Prime Minister of India and four Cabinet Ministers participated at the congress and spent two days listening to the scientists. Unfortunately, interactions in Sri Lanka are nowhere near it. Sri Lanka gives the opportunity to the pseudoscientists to mislead law makers at individual levels.

Obviously, the Sri Lankan food production system affected by the absence of required fertilizer inputs is not in a position to deliver the staple and complementary food for the nation. It is already late to put things back in the track before everything gets beyond control. Let the country believe in science and its true scientists at least now and act sensibly.

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