Lead

Lead is considered to be one of the most toxic metals since its effects are many, additive, and severe. Among its many adverse effects, lead can disrupt enzymes ability to function, cells' ability to use calcium, which is essential for many cellular activities, and nerves' ability to transmit messages. Lead poisoning can therefore cause damage to most systems of the body, including, but not limited to, the gastrointestinal, neuromuscular, central nervous (CNS), hematological (blood), and renal systems.

Children more commonly experience CNS manifestations including mental impairment, while gastrointestinal occurrences are more common in adults, although symptoms can vary with levels of exposure and an individual's health status.

Lead is oftentimes stored in the bones and because of its unique relationship with calcium, is mobilized into the bloodstream during times of calcium deficiency (for example, when the diet is low in calcium-rich foods) or greater calcium requirements (for example, during pregnancy and adolescent growth spurts).

Although there has not been enough research conducted involving humans to establish whether or not lead is a confirmed carcinogen (chemical capable of causing cancer), there is sufficient evidence in animals that it is carcinogenic for it to be classified as a probable human carcinogen by the Environmental Protection Agency.

Lead toxicity is of great concern during pregnancy not only because it is a time demanding greater calcium requirements but because lead can cross the placenta, adversely affecting the fetus, especially in later stages of development, and causing poor pregnancy outcomes. Lead toxicity may also impair reproductive function and contribute to infertility.

There are many possible dietary sources of lead exposure. Drinking water may be contaminated with lead from either natural sources, acid rain or agricultural runoff, or from pipes that are made of either lead or PVC since lead stearate may be used to stabilize PVC pipes. If foods were grown on soil that was contaminated with lead (which could happen through a variety of means including the use of lead-containing agricultural chemicals) or in an area that had significant levels of airborne lead pollution, the lead may have migrated into the food. Animal foods from animals raised in lead-contaminated environments may also be sources of dietary lead. Processed foods may be further contaminated with lead if they were prepared with lead-containing water or had exposure to either processing equipment, packaging materials or storage materials (notably metal cans) that contained this metal. Migration of lead-based inks from plastic packaging, such as bread bags, can contaminate food if they come in contact with acidic foods.

Another source of dietary exposure is through lead-glazed pottery, ceramicware and porcelain, especially if the serving pieces are heated or the food that is in contact with them is acidic. While the Food and Drug Administration (FDA) has created guidelines for the acceptable level of lead allowable in these products, lead may still be present in newer pieces if the glaze was improperly sealed. Additionally, vintage and antique pieces created before the FDA guidelines and pieces imported from other countries that may not have guidelines such as those that exist in the United States are more likely to be made with lead glaze.

Other sources for lead exposure include air pollution from industrial sites, incineration and cars. A significant source of exposure for some young children is the consumption of chips and dust from lead-containing paint that has flaked off of walls and furniture.

Lead may enter the environment during the mining, processing or manufacturing stages of this metal, the disposal or recycling of lead-containing products or the use of lead-containing pesticides and agricultural chemicals. Although lead-containing gasoline was banned in the United States and other countries, there are many countries where it is still used.

Lead toxicity is of great concern during pregnancy for several reasons. The increased calcium demands of pregnancy pull lead deposits out of the mother's bones and into her blood stream where it can do greater damage to her body's systems. Lead can also cross the placenta to adversely affect the fetus, especially in later stages of development, and cause poor pregnancy outcomes.

There are many possible dietary sources of lead exposure. Drinking water may be contaminated with lead from either natural sources, acid rain or agricultural runoff or from pipes that are made of either lead or PVC since lead stearate may be used to stabilize PVC pipes. If foods were grown on soil that was contaminated with lead (which could happen through a variety of means including the use of lead-containing agricultural chemicals) or in an area that had significant levels of airborne lead pollution, the lead may have migrated into the food. Animal foods from animals raised in lead-contaminated environments may also be sources of dietary lead. Processed foods may be further contaminated with lead if they were prepared with lead-containing water or had exposure to either processing equipment, packaging materials or storage materials (notably metal cans) that contained this metal. Migration of lead-based inks from plastic packaging, such as bread bags, can contaminate food if they come in contact with acidic foods.

Another source of dietary exposure is through lead-glazed pottery, ceramicware and porcelain especially if the serving pieces are heated or the food that is in contact with them is acidic. While the Food and Drug Administration (FDA) has created guidelines for the acceptable level of lead allowable in these products, lead may still be present in newer pieces if the glaze was improperly sealed. Additionally, vintage and antique pieces created before the FDA guidelines as well as in pieces imported from other countries that may not have guidelines such as those that exist in the United States are more likely to be made with lead glaze.

Other sources for lead exposure include air pollution from industrial sites, incineration and cars. A significant source of exposure for some young children is the consumption of chips and dust from lead-containing paint that has flaked off of walls and furniture.

Lead may enter the environment during the mining, processing or manufacturing stages of this metal, the disposal or recycling of lead-containing products or the use of lead-containing pesticides and agricultural chemicals. Although lead-containing gasoline was banned in the United States and other countries, there are many countries where it is still used.

Probable human carcinogen

Capable of dysregulating enzymes, altering cellular calcium metabolism and slowing nerve conduction, among its varied other adverse effects, lead poisoning can compromise the functioning of most systems of the body, including, but not limited to, the gastrointestinal, neuromuscular, central nervous (CNS), hematological (blood), and renal systems. Children more commonly experience CNS manifestations including mental impairment while gastrointestinal occurrences are more common in adults although symptoms can vary with levels of exposure and health status of individual. Lead is oftentimes stored in the bones and because of its unique relationship with calcium, is mobilized into the bloodstream during times of calcium deficiency or greater calcium requirements. Lead toxicity may also impair reproductive function and contribute to infertility. Although there has not been enough research conducted involving humans to establish whether or not lead is a confirmed carcinogen (chemical capable of causing cancer), there is sufficient evidence in animals that it is carcinogenic for it to be classified as a probable human carcinogen by the Environmental Protection Agency.