Occupational lead exposure is a potential worry for people in many lines of work.
After all, lead is a naturally occurring metal used in many products – including paints, batteries, ammunition, rubber materials, plastics, glassware, ceramic glazes, jewelry, radiation shielding and gasoline.
It can affect many organ systems and presents a serious health risk.
Indeed, lead is a concern for those remediating older homes, refinishing older steel bridges and overpasses, working in the battery, smelting, welding and brazing or ceramics industries, as well as police or military personnel. Inhalation and ingestion of lead-bearing dust and fumes are the major routes of absorption.
Secondary exposure occurs when employees bring lead dust back to the home, which can contaminate the home environment and cause elevated blood lead levels – or BLLs – in family members. This is why employees potentially exposed to lead should change clothes and shower before leaving work.
Often, there are no symptoms of lead toxicity early on, but there are many as exposure continues.
Acute lead exposure usually causes abdominal pain, nausea/vomiting, headache and fatigue.
Chronic lead exposure begins with the acute symptoms, but can progress to involve more organ systems. Fatigue, apathy and irritability are common symptoms. High blood pressure, infertility and gout also can develop.
Neurological symptoms eventually develop: wrist weakness, insomnia, confusion, poor concentration and memory problems. Brain injury and coma are extremely rare, but can occur with very high lead levels.
Lead toxicity can be detected via blood tests, which might reveal anemia and declines in kidney/liver function.
Physical exam findings may reveal elevated blood pressure, pale color from anemia, a blue-gray lead line on the gums and ankle/wrist weakness.
The federal Occupational Safety and Health Administration created an enforceable lead standard in 1978 and mandated a medical surveillance program which employers must follow. Employee participation, is encouraged, however it is not mandatory.
<OSHA’s permissible exposure limit is 50 µg/m3 (50 micrograms per cubic meter) eight-hour TWA (time weighted average). This means an employee cannot be exposed to at or above this average air level over an eight-hour day.
<A lead medical surveillance program is mandated when air lead levels are at or above the OSHA action level of 30 µg/m3 8-hour TWA more than 30 days a year. If this is the case, workers need a medical examination before potential lead exposure and must have BLLs and zinc protoporphryin levels drawn every six months.
<Under the OSHA lead standard, medical exams are required:
<Annually, if any BLL is 40 µg/dl or more.
<Whenever a worker develops signs or symptoms of lead toxicity, wants to be examined or has questions regarding the health effects of lead.
<Mandatory medical removal is required when any of these occur:
<A BLL is 60 µg/dl or higher, confirmed by a second BLL within two weeks.
<When the average of the past three BLLs is 50 µg/dl or more.
<When the employee has medical conditions that put them at increased risk from lead exposure. (Medical removal ends when the employee has had two consecutive monthly BLLs 40 µg/dl or less.)
As always, prevention is the best medicine. A clean work environment is key to reducing employee lead exposure.
There should be clean areas for eating. Smoking should be prohibited. Showers should be available to employees.
Work clothes should be left at the worksite and laundered by the company. Respirator protection should be provided when lead dusts and fumes are present.
Treatment of lead poisoning is determined on a case-by-case basis and is tailored to the individual employee, using either oral or intravenous chelation therapy.
It is the health care provider’s responsibility to take a thorough work and medical history, perform an appropriate physical exam, order appropriate tests, counsel and advise the employee and give a written medical opinion to the employer.
Employers must notify employees of their BLL results in writing within 15 days of receiving the results. If the BLL result is 40 µg/dl or more, the employer must notify the employee in writing within five working days of receiving the result.
If your company works with lead, take measures to keep your air levels below the OSHA action level.
If your air sampling studies reveal lead levels above the OSHA action level, make sure you provide a clean working environment and appropriate personal protective equipment for employees. And contact your occupational health provider to set up a lead medical surveillance and respiratory protection program.
Dr. Kevin Vrablik is board certified in occupational medicine at Lehigh Valley Health Network – HealthWorks. With four offices dedicated solely to occupational health, he provides treatment and health care needs for workers and companies. Also the medical director for LVHN’s employee health services, he can be reached at firstname.lastname@example.org.