Lead is a naturally occurring heavy metal that is found all over the world. People have used it for centuries in products ranging from cosmetics to gasoline and from ceramics to paint. As one of the first metals used by humans, it was also the cause of the first documented occupational illness, a case of lead colic recorded in the 4th century BC.
Despite restrictions on the use of lead in industrial settings, it remains a significant source of occupational illness. Research estimates the direct medical cost of lead poisoning to be $141 million with an additional $251 million in indirect costs per year for the roughly 10,000 US workers who suffer from high occupational lead exposure.
Sources of Lead Exposure
In the early 1970s, the U.S. government began an over twenty-year process to remove lead from gasoline. It was also banned from use in house paint in 1978, although it can still be found in the paint on older structures. This paint can chip and turn to dust which is then inhaled. In a large enough volume or over an extended period of time, this can lead to poisoning.
The federal government banned lead for use in plumbing, including solders, faucets and pipes, in 1986. However, this too is taking time to eliminate completely and both the lead from paint and in plumbing can contaminate soil and drinking water.
OSHA estimates that well over three million American workers could be exposed to lead in a wide variety of occupations, from painters to police officers to shipbuilders. The Centers for Disease Control (CDC) maintains a list of the workplaces most at risk for lead exposure.
Children can also be exposed to lead at the workplace when it is brought home on a worker or a worker’s clothing. This can be very serious as children, especially young children, are far more susceptible to the toxic effects of lead.
Methods of Lead Exposure
Lead exposure can occur through ingestion, such as eating, drinking, smoking, or via contaminated hands, clothing, or surfaces. More frequently, it occurs through the inhalation of dust or fumes. Once inhaled, it passes through the lungs and into the bloodstream and various organ systems.
Fumes are considered much more dangerous than dust. The use of heat guns, soldering, welding, torch cutting, and smelting are all workplace operations that can lead to exposure to dangerous lead fumes. Lead dust exposure can occur through the removal of old lead paint, using or cleaning firing ranges, remodelling or renovations, handling of scrap metal or leaded cables or wires.
Health Risk of Short-Term Lead Exposure
If lead levels are high enough, even short-term exposure can result in serious health problems. However, because lead poisoning is often initially asymptomatic, it is often difficult to catch until after the damage to organs is done, which is why employee monitoring is so critical. Anemia, kidney and brain damage are all severe symptoms of exposure to excessively high levels of lead. It can also cross the placental barrier and damage a baby’s central nervous system. Additional symptoms of adult exposure can include:
- Abdominal pain
- Loss of appetite
- Memory loss
- Pain or tingling in the hands and/or feet
- General weakness
Health Risks of Long-Term Lead Exposure
The long-term effects of lead poisoning can be even more damaging. Lead is considered a carcinogen by both the Environmental Protection Agency (EPA) and other organizations. Long term exposure is also linked to high blood pressure (hypertension), heart disease, kidney disease, and reduced fertility. Additional risks associated with long term exposure to lead can include:
- Abdominal pain
OSHA has set limits on the amount of lead exposure an employee may receive as well as the levels at which employers must initiate specific compliance and remediation actions. There are slight differences for workers in particular industries such as construction, but exposure limits are similar for all workers.
The permissible exposure limit is 50 µg/m3 over an eight-hour, time-weighted average for all covered employees. Employers must also initiate medical surveillance for all employees exposed to levels above 30 μg per m3 for more than 30 days, regardless of whether the employee wears respiratory protection or not.
OSHA also requires employers to follow basic safety protocols designed to protect workers in the workplace and prevent workers from carrying toxic lead into their homes.
These protocols include:
- Testing the air for lead
- Testing workers' blood-lead levels
- Informing workers of any exposure
- Providing training on the risks of exposure
- Establishing controls for limiting workplace lead dust and fumes
- Providing personal protective equipment (PPE) for workers
- Providing shower, washing and changing facilities
- Providing clean, safe areas for workers to store street clothes
Additional Ways to Protect Your Workers
In addition to OSHA standards, other measures can help you protect your workers. Start with education efforts that emphasize the risks and as well as ways workers can help mitigate those risks. Encourage all workers to keep work clothes in the workplace and to change into street clothes before leaving work. Proper hygiene, including frequent hand washing as well as showering before leaving the job, can help reduce lead exposure for both the worker and their family.
These additional measures should include engineering controls, PPE and appropriate workplace practices. Engineering controls can consist of the substitution of materials, isolation of lead using a containment structure and ventilation using a local exhaust system. PPE must include a respirator. In addition to personal hygiene, housekeeping activities designed to control dust and regular equipment inspection are good workplace practices to institute.
Lead exposure is a serious workplace hazard that affects workers in a wide range of industries. Still, proper controls and mitigating efforts can significantly reduce the threat to your workers and their families.