Monday, October 17, 2011


In to day's world man suspects that every thing he comes into contact with, can be dangerous and with modern style of living, the number of chemicals used in thousands of consumer products is increasing every day. Many of these have been studied for their safety and clearance for use given based on available scientific data. However with widely divergent conclusions thrown up by such studies, no firm conclusion can be drawn regarding the safety of any chemical that comes into contact with human being or consumed through foods. To cite an example both Saccharine and Cyclamate were hailed, when they were introduced as sugar substitutes, as "God sent" and enjoyed wide scale acceptance, especially by the consumers who are sugar "intolerant"! A few years later both were implicated in many health disorders by toxicologists leading to their ban in many countries. This trend was reversed later after finding the earlier studies faulty and unreliable and to day both these sugar substitutes are allowed in many countries!

Recent uproar regarding Arsenic content in Apple juice is another example of misplaced concerns on the part of some consumers and activists, in spite of the fact that arsenic is a common contaminant in air since time immemorial. Finding fault with regulatory agencies for not banning the Apple juice is totally misconceived and deserves contempt and pity! Probably those who find danger in every food they eat must think of migrating to another planet where they may get the ideal living condition aspired by them. Life on earth is based on a balance of risks and benefits associated with any endeavor and one has to get reconciled to this truth. It is true that ingestion of Arsenic by humans at high doses can be dangerous and this trace mineral is implicated in development of cancer of Lungs, Bladder, GI Tract and Skin, especially when consumed through water containing more than 50 micro grams (ug)per liter. This is the reason why only a low level of 10 parts per billion of Arsenic is allowed in drinking water.

Arsenic concentration in air can be about 0.02 to 4 nano gram (ng) per cubic meter in rural areas where air is considered relatively pure. This can go up to 200 ng per cubic meter in urban areas where industrial emissions and other factors can contribute to higher Arsenic concentration. It can go as high as 1000 ng in areas near smelters. Sea water contains arsenic as high as 1000 to 2000 ng per liter while ground water may also have same levels of this toxic metal. There are reports that water sources near volcanic rocks, sulfur mineral deposits can have Arsenic as high as 3000 ug per liter! Normally soil samples contain about 1-40 mg of Arsenic per kg. While discussing about the toxicity of Arsenic it is to be noted that inorganic Arsenic is more dangerous and out of the average consumption of Arsenic through the food, about 20-300 ug/day, 25% is the inorganic version. There is the million dollar question as to why no agency has set an upper limit for Arsenic that can be considered safe when ingested through food and probably this may be exercising the mind of many people who entertain apprehension on this score.

It is true that long term exposure to Arsenic, especially at high levels is injurious but setting up an upper limit for safety for every food is not considered practical. Water is a critical material consumed in large quantities, 2-3 liters a day and greater precaution is necessary in avoiding unsafe levels. Therefore such limits have been incorporated in potable water standards. One of the reasons for giving priority to water is that most Arsenic present in water is inorganic in nature and hence more dangerous. In contrast Arsenic present in foods is organic type with considerably less toxicity. So far no food product has been reported to have Arsenic content more than that set for water and therefore the apprehension on this score may be misplaced.

According to present data available Sea foods including fish contribute about 77% of the Arsenic exposure by average person while cereal products, vegetables, meat products and dairy products account for 10%, 6%, 4% and 3% respectively. Further the present safe Arsenic intake level is 15 ug per kg body weight per week (PTIW) while through all sources the average intake is reported to be less than 7 PTIW as per some studies. Rice is one of the food materials, suspected to have a tendency to absorb Arsenic from the soil because of profuse water use and rice products originating from the US and France have been reported to contain 0.24 to 0.28 mg per kg posing some concern at one time. Use of Arsenic containing crop protectants in the field also has been implicated in accumulation of the metal in paddy crops. Fortunately in high rice consuming countries like India and Egypt, the Arsenic levels in the rice are never known to be above 0.1 mg per kg. While continued monitoring of foods for Arsenic level is necessary to pre-empt any possible poisoning episode in future, consumers should not be unduly worried about Arsenic at least for the time being.


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