Not long ago we looked at what metals are considered ‘healthy’ and can be beneficial to us. This time we are going to look at metals that can be ‘unhealthy’ or harmful to us if we are exposed to them in the wrong way. Many of these are well known, and of course can still be used as long as they are handled with the proper care and attention. If you regularly come into contact with these metals, or work with them, it is incredibly important to make sure you adhere to any safety guidelines.
Lead may have a negative effect on human health in any measurable form, which means it should always be handled with the utmost care. If ingested or inhaled in any amount it can be poisonous and causes damage to the nervous system. Lead is still used in building construction, as well as lead-acid batteries, solders and bullets. If working with lead, the National Institute for Occupational Safety and Health (NIOSH) has recommended an exposure limit of 0.050 mg/m3 over an 8-hour workday.
Iron is essential to our health, however, an excess of iron intake can be detrimental to us. Iron poisoning can occur although it is mainly associated with young children who have consumed large quantities or iron pills inadvertently. It is important for iron pills, generally taken by pregnant women, to be kept out of reach of small children.
Lithium is often used in medical treatment, specifically to treat bi-polar disorder. In high doses lithium can be toxic and it is important for medical practitioners to carefully monitor patient’s dosage for this reason.
Manganese is a nother metal that has become an active issue in workplace safety. Chronic exposure can lead to negative psychiatric effects and motor disturbances with the symptoms being similar to Lou Gehrig’s disease and multiple sclerosis. There have been several product liability lawsuits against manufacturers of arc welding supplies for manganese poisoning.
Mercury is used worldwide in things such as thermometers, barometers, fluorescent lamps and float valves. Concerns about the toxicity of the element have led to mercury thermometers being largely phased out in favour of alcohol or galinstan instead though. Mercury poisoning can occur through inhalation or ingestion and can affect the brain, kidneys and lungs. The export of mercury from the European Union has been prohibited since March 2010 in an effort to limit the use of mercury for health reasons.