Getting the lead out

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India’s favorite snack Maggi Noodles has been put under the microscope after ‘abrupt’ tests revealing excessive amounts of lead in it. Thanks to Barabanki’s food safety inspector VK Pandey. This set off a chain reaction that lead to the inspection of various other products in the market. Much to our surprise, lead was found and so was detergent. Maggi noodles and other products have been enjoying this unchecked prosperity for who knows how long.

Lead is a chemical element (goes by the symbol ‘Pb’ in the periodic table, for plumbum in Latin) that is thought to have ended the Roman Civilization. The Roman Empire’s water supply used lead pipes (without any coating to it), unlike iron and steel that are commonly used today. In addition to this, they even added lead acetate to makes their wines sweeter!

In 1922, lead in the form of tetraethlyllead as an anti-knocking agent was added to petrol to make vehicles run smoothly. Fifty years down the line i.e. around 1970, the infamous tetraethyllead was everywhere, in all the vehicles around the world. In the year 2002, 50 countries banned leaded gasoline and adopted unleaded gasoline. In 2007, 90% of the world’s countries had banned it. In 2008, 21 countries were still using it. Why did so many countries ban it? Who knew that lead could be poisonous to us humans? The Romans didn’t know. The men who used lead in petrol didn’t know, or did they?

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Leaded Petrol Phase-out: Global Status April 2014, Source: UNEP

One man named Clair Cameron Patterson knew. Elaborated in ‘Cosmos: A Spacetime Odyssey, episode ‘The Clean Room’, Patterson, a geochemist, unmasked the toxic nature of lead while looking for the true age of the Earth. His efforts to make sure that lead gets eliminated from petrol is commendable. He fought against the political tide all by himself. Why did he do that? He, of all the people, knew how dangerous lead is to people.

Lead bioaccumulates as our body doesn’t know how to deal with heavy metals like lead, mercury, chromium etc. It sits inside you, in your bones, and inhibits the body to function well, havocs it. It attacks your nervous system, your kidneys, and a lot more. In scientific terms, this makes lead a ‘Persistent, Bioaccumulative and Toxic (PBT) chemical’. As the Food Safety and Standards Authority of India (FSSAI) puts it,

“Short-term exposure to high levels of lead can cause brain damage, paralysis, (lead palsy), anaemia and gastrointestinal symptoms. Longterm exposure can cause damage to the kidneys, reproductive and immune systems in addition to effects on the nervous system. The most critical effect of low-level lead exposure is on intellectual development in young children and like mercury, lead crosses the placental barrier and accumulates in the foetus. Infants and young children are more vulnerable than adults to the toxic effects of Lead, and they also absorb lead more easily. Even short-term low-level exposure of young children to lead is considered to have an effect on neurobehavioural development. Consumption of food containing lead is the major source of exposure for the general population.”

How did lead get into these noodles? It could have entered the noodles through air, water, soil, plastic packaging, ‘masala‘, noodles, or industrial effluent. Lead has been used in storage batteries, weapons, lead paint, and even to protect workers from radioactive elements. It is still one of the most commonly used non-ferrous metals in the world. Any one can become exposed to lead through inhalation or ingestion of lead particles that are generated from industrial and domestic activities. Lead still serves many purposes and used as:

  • a coloring agent in stained glasses for reducing the radiation transmission
  • in fishing sinkers and in balancing wheels of vehicles
  • in polyvinyl chloride (PVC) plastic for coating the electrical metal wires
  • for shielding from radiation in x-ray laboratories
  • in electronics its use as soldering agent
  • as a coolant in lead-cooled fast reactors
  • for sound proofing system
  • in building constructions e.g. sheets as architectural metals in roofing, cladding, flashings, gutters and joints, etc
  • water proofing media
  • in lead-based semi-conductors such as lead telluride, lead selenide and lead antimonide are being used in photovoltaic (solar) cells and infrared detectors
  • in making sculptures
  • a additive to brass to reduce machine tool wear

According to FSSAI, the permissible limit for lead in food is 2.5 ppm, i.e. 2.5 mg of lead per kg of body weight. Some of the samples indicated levels of 17 ppm, that’s about 7 times higher. What does ‘Permissible Exposure Limit’ (PEL) mean anyway? Who decides this? Isn’t it basically a ‘legal’ limit to lead content in food? 2.5 ppm or less, lead is going to accumulate in the human body. If it accumulates in large amounts, it leads to poisoning. PEL is the so called regulatory number, against advisory/recommended values, which can only be advised and not enforced. According to the World Health Organization, there is no known level of lead exposure that is considered safe.

Moreover, please note that ‘2.5 ppm’ mentioned above is only applicable to ‘Foods not specified’ under the Food Safety and Standards (Contaminants, Toxins and Residues) Regulations, 2011. It is not the same, for say, baking powder. For baking powder, PEL is as high as 10 ppm. Standard procedure is followed for testing of elements in food samples and specific determination methods are followed for determining specific elements such as lead.

Lead poisoning is preventable but the damage is done in many cases and people have been exposed to lead. Some believe that they can cure it through Chelation Therapy. Viral messages suggesting chelation therapy with coriander are being passed along. Drugs called “chelators” [KEY-lay-ters] bind to the metals in the blood stream. This metal-chelator compound then gets eliminated in the urine. This therapy has its side effects but is a preferred choice for heavy metal poisoning. Chelation therapy however can only remove lead from blood, and not from your bones as it is difficult to do so. Let’s not forget what Benjamin Franklin said, ‘An ounce of prevention is worth a pound of cure.’

References:

Note 1: One can think on similar lines for MSG and Sweeteners.

Note 2: In Indian languages lead is known as ‘sisa’, ‘ranga’, ‘haridra’, ‘seemak’, ‘cheen’, ‘sindhur’ (Hindi/ Sanskrit), ‘eeyam’ (Malyalam) and ‘tipu’ (Pali).

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