Lead crystal is a heavy, durable glass prized for its brilliance and clarity. It was developed in the 17th century, by combining molten quartz with lead compounds. The final product usually contains from 24 to 36 percent lead oxide and is widely used today for serving beverages.
However, questions are now being raised about the safety of crystal. Scientists have found that when crystal comes in contact with acidic beverages, some lead dissolves into the liquid. The amount depends on the lead content of the crystal, the type of beverage, and the length of time they are in contact with each other. However the amount of lead obtained from crystal is in general very small.
Studies show that acidic beverages such as port or wine will dissolve more lead from crystal than less acidic drinks like scotch or vodka. Acidic non-alcoholic beverages such as fruit juices and soft drinks also absorb lead. Generally, the longer a beverage sits inside a crystal container, the more lead is absorbed by the liquid.
However, the actual amount of lead released from crystal glasses over the course of a normal meal tends to be low. Tests show that the resulting lead levels in both alcoholic and non-alcoholic drinks are usually well below 200 parts per billion -- the maximum allowable lead concentration in Canadian beverages.
By contrast, beverages stored in crystal decanters can accumulate very high levels of lead. Scientists have found lead concentrations of up to 20 parts per million - 100 times higher than the Canadian limit - in wines kept for weeks or months in crystal containers. As a general rule, do not store any beverage in crystal decanters for extended periods of time. To inhibit lead from dissolving in the beverage, some manufacturers are now coating the interior of lead crystal containers.
Lead has no known use in the body. Once absorbed, it circulates in the bloodstream, and either accumulates in tissues or is excreted as waste. Lead can be found in soft tissues, such as the liver and kidneys, or hard tissues, such as bones and teeth, where it can remain for more than three decades.
Studies have shown that exposure to even small amounts of lead can be harmful. Long- term exposure to increased lead levels may produce flu-like symptoms, such as lack of appetite, fatigue, irritability, headaches, and joint pain. When the body is under stress, such as during pregnancy or a serious illness, bones may release increased amounts of lead into the bloodstream. Elevated levels of lead have been linked to blood and kidney problems, as well as neurological disorders.
Children and developing fetuses are particularly at risk, because they grow rapidly, and absorb lead more easily than adults. Childhood neurological disorders such as hyperactivity, learning disabilities and possibly lower IQ scores have been linked to lead. Studies also indicate pregnant women with high levels of lead in their blood have a greater risk of miscarriages, stillbirths and premature deliveries.
Your family doctor can determine how much lead is in your body by a simple blood test. The Federal/Provincial Committee on Environmental and Occupational Health recommends that action be taken when the amount of lead in your blood reaches 10 micrograms per deciliter. This should include identifying and removing the source of contamination.
Chelation therapy - a chemical means to remove lead from the body - is usually considered only when lead levels in the blood are much higher.
The federal government is working to limit sources of lead exposure for Canadians. As a result, lead is no longer allowed in gasoline or used in the manufacture of consumer paints. In addition, the use of lead in domestic wine capsules is also being phased out. Recently, the Government of Ontario made it illegal to use lead in wine capsules.
For more information about lead and your health, contact your physician or the Poison Information (or Control) Center in your area.
May 10, 1995