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Sources of Lead

A special focus on toys imported from China…

Over last few decades, lead poisoning has emerged as one of the major threats to environment and human health. There are many ways in which humans are exposed to lead: through deteriorating paint, household dust, bare soil, air, drinking water, food, ceramics, home remedies, hair dyes and other cosmetics. Much of this lead is of microscopic size, invisible to the naked eye. More often than not, children with elevated blood lead levels are exposed to lead in their own home. The major sources of lead poisoning are:

Drinking Water: More often, lead in drinking water comes from the water supply lines or a building's own plumbing rather than from the water system resources. Plumbing materials containing lead may corrode and release lead over a period of time when they are in contact with water. Its quite likely for lead to be present in following cases:

If water supply pipes contains lead

If fixtures or fittings are made up of brass, bronze or other alloys

If lead solder was used on the pipes

If water is acidic in nature due to impurities.

Lead-contaminated drinking water is most often a problem in buildings that are either very old or very new. Older buildings have higher levels of lead in plumbing materials whereas newer systems leach lead more rapidly than old ones because fittings are in direct contact with the water.

Food: Lead in food usually comes from the container but it may come from water used to prepare the food or food that has been contaminated with lead dirt or dust and not washed. Lead cannot be seen on food. Containers with lead are usually pottery and ceramics with a lead glaze and lead crystal decanters or containers.

Residential Paint and Soil: Deteriorating lead-based paint, lead contaminated dust, and lead contaminated residential soils are some of the common sources of lead contamination and lead poisoning.

People living near areas where lead is processed and worked upon, can ingest lead through dust on their hands. Those living near highways are exposed to lead through automobile and truck exhaust. Even those in urban areas are not exempted! They are frequently exposed to lead paints, vessels and other leaded items.

Children under six are especially sensitive to lead poisoning because they play in lead-contaminated dirt or house dust then swallow the lead from dirty hands and faces with their food. Some children deliberately eat paint or dirt because they like the taste -a habit called pica.

Lead in Paint: Some products imported from China have been reported to have exceedingly high lead content. They mainly include children’s toys, kid’s metal jewelry etc. About 103,000 multicolored necklaces, bracelets, earrings and charms imported by Tween Brands Inc. of New Albany, Ohio, were reported to be affected.

Not just jewelry, toy drums coated with red paint were found to contain excessive levels of lead. About 4,500 of the Eli's Small Drums and Liberty's Large Drums were recalled. They were earlier sold in gift and collectible stores nationwide.

About the Author

This Article is written by Tarun Gupta, the author of TestCountry Health Information Resources, a longer version of this article is located at Sources of Lead, and resources from other home health and wellness testing sources are used such as Health Hazards Detection Kits.

why are the plasma membranes of plant and animal cells difficult to see on a normal school microscope?

would appreciate all answers, and pleasae list a source. thanks.

Because it's such a thin delineation of the inside and outside of the cell. This is for animal cells. The reason why it's difficult to see on a plant cell is that normally a plant cell is hypertonic in relation to the fluid it's in resulting in the cell being turgid. This causes the Plasma membrane to push against the cell wall making it difficult to see the difference between the two. If you were to however put the plant cell in a saline solution it's much easier to see as the membrane will retract from the wall as water leaves the cell.

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