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Lead is a metal found in the environment. When breathed or absorbed through the digestive tract or the skin, it can cause damage to the nervous system. Lead poisoning is reported not only from industrial environments but also from the use of firearms at shooting ranges, cosmetics containing kohl and old oil paints. Children are particularly vulnerable to lead poisoning. Test results are expressed in micromoles of lead per litre of blood (µmol/L). Multiply this result by 20 to compare with data expressed in micrograms per decilitre (µg/dL). (Example: 0.5 µmol/L x 20 = 10 µg/dL).

The higher the blood lead, the greater the exposure to lead. However, blood levels do not necessarily reflect total lead levels in the body, particularly over the long term, since lead gradually moves out of the blood to be stored in the teeth and bones. The health risk depends on the person’s age. For children under age 12, blood levels above 0.25 µmol/L indicate an environment that is hazardous to their health. In individuals age 12 or older, blood levels greater than 0.25 µmol/L are considered toxic, whereas blood levels greater than or equal to 0.50 µmol/L are subject to mandatory reporting to the public health department.

Term of the Week

Hot zone

A hot zone is a section of a facility (sometimes an entire facility or even a city district) where there is a high risk of contamination by patients with an infectious disease. All individuals entering a hot zone must respect appropriate protective measures. By analogy, “cold zone” and “warm zone” are used to refer to areas where there is no infected individual or only individuals suspected of having an infection.