Main Causes of Lead Poisoning

Benjamin Franklin once said – “The only thing more expensive than education is ignorance” and this holds perfectly true for lead poisoning. With years of knowledge on toxic effects of various heavy metals like lead, they persist to be used extensively in various products of common use found in and around our homes posing threat to humans and other forms of life.

Present in natural deposits as ores, lead is a soft, heavy, and malleable metallic element that has been exploited extensively for commercial purposes because of its useful physiochemical profile. It is used extensively for a diverse array of purposes including, but not limited to, construction industry, oil-based paints, lead-acid batteries, bullets, weights, electronic solders, fusible alloys, radiation shields, statues and sculptures, lead cooled fast reactors, candle wicks, PVC electric cords, fishing sinkers, plumbing, coloring element in ceramic glazes and as a sound deadening layer in production studios. Needless to say, there are literally thousands of potential sources of lead contamination around us and some of the main sources that contaminate air, water and soil in most of the developed countries are:

• Automobile emission: Until mid 90’s, tetraethyl lead was extensively used as a gasoline additive. In early 90’s, U.S. Congress passed the Clean Air Act Amendments requiring lead-free gasoline followed by the revisions of EPA emission regulations declaring the use of leaded gasoline as illegal. This has resulted in a substantial drop in lead emissions. Although vehicle emission is not much of a problem as far as lead contamination is concerned nowadays, however, with decades of burning huge quantities of leaded gasoline, lead has already been deposited on the soil. This accumulated lead has found its way into a lot of homes across the states as it tends to persist for a long time because of its non-degradable nature.

• Drinking water: Earlier, Lead was commonly used in household plumbing materials and water service lines in the form of lead pipes, fixtures and solder. After the introduction of Section 1417 of the Safe Drinking Water Act 1998, the use of leaded plumbing material has decreased substantially as this section requires the plumbing material to be lead-free. However, if you have older homes or fittings, it is likely that you may have older lead pipes and fixtures which may get corroded and contaminate the water. Lead may also occur in drinking water by direct contamination of the natural water used by the water system due to lead mining and smelting operations. In such cases, some shellfish such as mussels may also get contaminated & get caught on a Sunday morning fishing expedition! The contaminated source water itself is quite unlikely to be supplied further given all the preventive and treatment measures taken at administrative levels. For more information, you may test drinking water for lead or consult the EPA’s National Review of LCR Implementation and Drinking Water Lead Reduction Plan.

• Agricultural Soil: Soil may get contaminated with lead either from lead dust dislodged from deteriorated paint or due to irrigation with water contaminated by lead pipes or by lead mining and smelting operations. Auto emissions may also have contributed a significant amount of lead to the soil already. From soil, it may either be taken up by some crops like lettuce and carrots or may stick onto plants with dust & get ingested directly.

• Lead Paint: Some forms of paint may contain lead chromate and lead carbonate as lead is a pretty useful ingredient as far as paint manufacturing is concerned as it speeds up pain drying, increases durability, and resists moisture that causes corrosion. However, these paints are one of the major sources of lead contamination as children can be exposed to lead by eating lead-based paint chips, chewing on objects painted with lead-based paints, or swallowing house dust that contains lead!

• Toys: Some toys may have either lead paint over them or they may be made up of plastics that contain lead as the use of lead in plastics has not been banned. When this plastic is exposed to sunlight, air, and detergents the chemical interactions between lead and plastics break down & may result in lead contamination.

Whatever the source, lead contamination may spread further through contaminated hands, food, water, cigarettes, clothing and a lot of other similar things.

Although various measures have been taken to check commercialization of lead products; environmental lead pollution remains a serious health hazard.