Lead is a toxic metal that can be harmful when ingested or inhaled (“ >Old debate on lead rekindled ”, June 23). It interferes with nerve transmissions in the brain and can damage blood cells. Children absorb more lead than adults do. High exposure can lead to kidney and neurological damage.
Lead-based paints and petrol additives have been phased out in most countries. However, lead compounds are added to lead crystal glasses, ceramics, pigments, drying agents, varnishes, insecticides and herbicides. More importantly, matches, explosives and pyrotechnics pollute the atmosphere with lead.
K.V.S. Krishna,
Chennai
There are many other chemicals that have a similar history as lead. Radium’s radioactive effect was not known for a while and millions of watches with radium dials were produced and where the characters and hands were hand-painted using radium-based paint. Arsenic was used in certain medication for many decades. Carbon tetrachloride, an ozone depleting substance, was another dangerous substance and India was one of the last countries to ban its use.
D.M. Mohunta,
Chennai
