Unlike other minerals present in the foods, lead is a toxic mineral found as a source of pollutant in the environment. Smaller quantities of lead do not cause much harm to the body until a specific threshold is reached. The lead poisoning threshold of the body is considered as the quantity of lead in the blood that causes significant harm to the body. The threshold is ten microgram per hundred milliliters of blood. Hence the lead toxicity is of great public health significance in today’s world.

Action of lead within the body:

Lead is a mineral and is found to be chemically similar to nutrient minerals like iron, calcium and zinc. Lead occupies the position of these minerals in the body and thus interferes with the normal functioning of the bodily reactions. For instance, normally heme (iron) combines with globin (protein) to form hemoglobin, which is a significant transporter of oxygen through blood. Lead occupies the position of iron and prevents the formation of hemoglobin, thus interfering with the transport of oxygen to the various parts of the body.

Symptoms of lead toxicity:

When nutrient minerals help in the performance of the body functions, lead strive to impair these functions. The main target organs of lead toxicity are nervous system, kidneys and bone marrow. The following are the symptoms:

• Growth retardation
• Anemia due to iron deficiency
• Short term memory loss
• Defective hearing and reactions
• Increased blood pressure
• Improper coordination and learning disabilities
• Low IQ

Malnourished children and pregnant women are more susceptible to lead toxicity. Lead directly transports across the placenta in pregnant ladies, which could result in severe malformations in the fetus.

Sources of lead poisoning:

All the foods contain at least negligible amounts of lead in them. The various sources from which lead is transmitted to food are discussed below:

• Exposure to lead from materials such as paints, batteries, inks and pesticides
• Consumption of foods from tin cans sealed with lead solder
• Transmission of lead from pipelines soldered with lead to drinking water is the major food source of lead
• Polluted environment composed of higher quantities of lead. These include lead in factory pollutants, power plant emissions, and factory wastes and so on.
• Leaded petroleum releases lead to air, whereas it is nowadays banned in India
• Infant formulas made from lead-soldered cans

In order to stay protected against the lead pollution, all we need to do is to be aware of the various above mentioned sources of lead poisoning.