The periodic table of elements is a representation of the basic matter that comprises all things on Earth. Some of these elements are familiar metals like copper, lead, tin, and iron. Others are less commonly known, like antimony, molybdenum, and cadmium.
When we talk about heavy metals, we're specifically referring to the metallic elements that have a high density and atomic mass.
Those metals might not sound harmful when they're listed on a high school classroom poster, but heavy metals present a very real danger in the industrial workplace.
Metals that we often consider harmless can become hazardous when their particles become airborne and are inhaled.
In terms of concentration, lead, mercury, arsenic, cadmium, beryllium, and cobalt are among the most concerning. These are found in various workplaces, not only metal smelters but also shipyards, pulp and paper mills, refineries, incineration facilities, and hydro transformer stations.
While these heavy metals don't always have an immediate adverse effect, they can build up in your body over time. Excessive exposure to metals can lead to serious health issues like cancer, reproductive issues, skin disease, major organ damage, and developmental effects. Health-based exposure guidelines are set by the U.S. Environmental Protection Agency (EPA), the California EPA, and the Agency for Toxic Substances and Disease Registry (ATSDR).
(Learn How to Reduce the Risk of Occupational Cancer)
Engineering controls can minimize exposure to heavy metals and their byproducts. Nevertheless, all workers who might be exposed to respirable heavy metals should be equipped with N95 respirators or better.
Employees not only need to be fitted with adequate respirators but also trained in their use and maintenance.
According to OSHA, employees must use respirators certified by the National Institute for Occupational Safety and Health (NIOSH) that are appropriate for the types and concentrations of airborne contaminants present.
While respirators are essential, it's important to remember that we can't rely on them exclusively. Many OSHA standards make it clear that respirators are a last resort and should not be relied on unless other, high-order controls have been implemented.
(Learn more about The Hierarchy of Hazard Controls)
Being aware of the concentration of metals you're dealing with is also critical to protecting workers from these hazards. OSHA’s hexavalent chromium standard, for instance, requires that employers conduct air monitoring to determine the employee’s exposure levels, then retest as needed. Assessing the sampled atmosphere will indicate whether additional protective guidelines must be followed, even if the concentration is below the applicable permissible exposure limit (PEL).
Reviewing and following the NIOSH-recommended exposure limits (RELs) and the American Conference of Governmental Industrial Hygienists’ (ACGIH’s) threshold limit values (TLVs) is recommended. They are a bit more demanding but will provide more protection for affected employees.
Following more stringent guidelines lets you err on the side of caution. With the consequences of heavy metal exposure being so severe and often lifelong, it's best to play it safe.
If you're working in the presence of heavy metals, make sure your employer is aware of the dangers. Speak up if respirators aren't provided – it's worth it to protect your health.