Metal

Metal (& metalloid) dusts and fumes are a broad category of compounds. Metal dusts are small particulates of metals. When monitoring for metal dusts, occupational exposure monitoring would be for the total fraction, the inhalable fraction or the respirable fraction.

Metal fumes are made when a metal is heated, then volatilized, and finally condenses in air. With metal fumes, the size fraction is predominantly respirable.

Although the category includes metalloids (elements that have a mixture of metal and nonmetal properties; such as arsenic), it is typically just called metal dusts and fumes. Each metal has different properties, and the size of the particles in the dust or fume will determine where the particles deposit in the respiratory tract. In many occupational settings, workers are exposed to multiple metals at the same time. For instance, nickel mining not only involves exposures to nickel, but also: copper, cobalt, gold, silver, among others. Another example is welding, which will always result in a complex mixture of metal fumes that may include beryllium, cadmium, chromium, lead, manganese, zinc oxide, among others.

Although many metal species target the same organs, each metal species has a distinct toxicity profile and has its own OEL. For example, long-term exposure to nickel compounds increases risks for chronic bronchitis and lung cancer. An acute exposure to zinc oxides present in metal fumes are often associated with metal fume fever, which causes flu-like symptoms like chills, fever, and nausea.

Lead Exposure

Download Guide, Legacy Lead Dust from Pipe Exposure

Unifor Local 975 created this guide in partnership with OHCOW to address health effects, prevention strategies, reporting and claims initiation for workplace exposure to lead dust.

Legacy Lead Dust From Pipe Dope is directed to all those supporting and protecting lead-exposed workers including:

Fellow workers: past, present and future
Employers
Managers
Supervisors
Joint Health & Safety Committee (JHSC) members
Health and safety representatives
Workplace union representatives Unions, employer associations, and health and safety professionals may also find this information useful.

Heavy Metals

Heavy metals are a group of metallic elements that are characterized by their high density and atomic weight, and often, their toxicity.

Heavy metals tend to accumulate in the body and can persist in the environment for long periods, posing a significant health risk. Examples of heavy metals include lead and nickel. Even though exposures can be to the same target organ, each has a unique toxicity.

For example, exposure to nickel compounds via the inhalation route is associated with cancer and the tumors are local to the respiratory tract (sino-nasal and lung) (Nickel Institute nd.)

An acute exposure to zinc oxide present in metal fumes are often associated with metal fume fever, which causes flu-like symptoms like chills, fever, and nausea.

Lead exposure via both “inhalation and through hand mouth contact (ingestion)” may result in adverse health effects even at relatively low exposures as lead is highly toxic.

Additionally, lead-based thread sealants, in particular, are extremely harmful to the health of workers, retirees previously exposed, vulnerable groups like pregnant women and children who come into contact with lead contaminated materials and items such as work clothing and vehicle seats etc.

Blood-lead concentrations > 5 µg / dL indicates recent exposure and the potential for health effects.

More recently, the measurement of lead in bone has been used as a biological indicator for chronic exposure and body burden as lead accumulates in the bones over many years.

The recently published “Agency for Toxic Substances and Disease Registry 2020”, provides studies that demonstrate an association between lead in bone. There is evidence that elevated lead in bone, a surrogate for long-term exposure to lead, produces adverse effects on the cardiovascular system. “Numerous studies show associations between bone lead concentration and increased blood pressure and increased risk of hypertension.” The most studied population is older men. “Results consistently show positive associations between tibia lead and systolic blood pressure (ASTDR 2020 p.69). Both tibia lead and patella lead were positively associated with ischemic heart disease, and patella and tibia lead were associated with an increased risk of coronary heart disease (ASTDR 2020, p.72).”

Follow the resource, "Legacy Lead Dust From Pipe Dope" to learn more about legacy lead dust, preventing cross-contamination as well as worker and workplace actions to protect workers, their families, and the public from the harmful effects of lead.