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Published: February, 2015; Vol 11, Num 9

 

How Much Lead Is in Your Blood?

LIUNA General
President
Terry O'Sullivan

Most health and safety advocates would agree that getting lead removed from gasoline was one of the greatest victories for public health of the 20th century. In 2015 and beyond, the risk of lead exposure for the general public has largely been reduced to that of lead-based paint used in buildings and houses built prior to 1978. But even though environmental sources of lead have been drastically reduced over the past several decades, occupational exposures remain a real concern.

Between 2002 and 2011, the Centers for Disease Control and Prevention (CDC) found that more than 11,500 adults in the U.S. had very high blood lead levels (BLLs). Over 90 percent of these cases were due to exposures at work. In addition to mining and manufacturing jobs, construction workers were among those with the highest levels of lead in their blood. Frequent work in renovation, remodeling and painting (such as on old bridges) were cited as the most common causes of lead poisoning.

“It’s estimated that over 90,000 bridges in the U.S. are still coated in lead-based paint,” says LIUNA General President Terry O’Sullivan. “This poses a major hazard to Laborers and other workers during renovation, repair and demolition. It will take a long-term commitment to address this issue. Repairing an aging transportation infrastructure across the U.S. and Canada should be our top priority.”

What Does It Mean to Have an Elevated BLL?

The CDC now considers an elevated blood level to be 10 µg/dL (micrograms per deciliter of blood) or above. Recent research has shown harmful effects at low levels of lead exposure – levels previously considered to be harmless. Occupational exposures are often much higher than these guidelines, making the effects of lead exposure much more severe.

Between 2002 and 2011, the CDC’s Adult Blood Lead Epidemiology and Surveillance (ABLES) program found that over 11,500 people had BLLs at or above 40 µg/dL. In construction, OSHA’s lead standards require medical removal from lead exposures after workers’ BLLs reach or exceed 50 µg/dL. Because OSHA’s lead standard doesn’t mandate protection to the low levels now recommended by the CDC, the Laborers’ Health and Safety Fund of North America recommends employers and workers take it upon themselves to prevent as much occupational lead exposure as possible.

The Many Effects of Lead on the Body

Lead exposure causes a wide range of negative effects in the human body. It affects behavior as well as the cardiovascular, neurological, reproductive, renal, immune and skeletal systems. These are only some of the effects of lead:

  • Reproductive issues including infertility in both men and women, miscarriage, premature delivery, low birth weight, pre-eclampsia and decreased libido
  • Decreased IQ in subjects with BLLs as low as 5 to 35 μg/dL
  • Renal failure and kidney dysfunction
  • Anemia
  • High blood pressure
  • Gastrointestinal issues including discomfort, nausea, anorexia, weight loss and severe abdominal cramps
  • Stomach, brain and breast cancer from the buildup of inorganic lead compounds

People with high levels of lead in their blood usually aren’t even aware of it. Lead builds up in the body over time, and the effects above could take a long time to manifest depending on the level of exposure. Lead exposure does present some noticeable symptoms, but they are often dismissed as problems people experience for a variety of reasons:

  • Persistent fatigue
  • Irritability
  • Loss of appetite
  • Hearing and vision impairment
  • Stomach discomfort and/or constipation
  • Limited attention span
  • Insomnia

Lead is particularly damaging to children, even at very low levels. It causes decreased brain function, behavior and hearing problems, as well as slowed growth. Some studies also suggest lead exposure increases a child’s risk for developing asthma. Because lead builds up in the bones over time, pregnant women risk passing lead to their fetuses.

Controlling Occupational Lead Exposure

Without the proper exposure controls and personal protective equipment (PPE), lead can quickly build up in the body. For example, a worker scraping paint from an old house ended up in the emergency room complaining of severe stomach pain. He was not using a respirator or disposable clothing and gloves were his only PPE. His BLL was 143 µg/dL.

Engineering and administrative controls for lead exposure include the use of local exhaust ventilation and limiting the amount of time workers spend performing tasks that cause lead poisoning. Workers should also use PPE, including appropriate respirators, gloves and clothing that can be cleaned or disposed of after each shift. Disposing of clothing prevents lead dust from traveling home to children and other family members. Workers should also practice proper hygiene during break times, especially when eating or smoking, to prevent inhalation or ingestion of lead particles.

OSHA’s current lead standard includes a permissible exposure limit (PEL) of 50 µg/m3 and an action level of 30 µg/m3 – the point at which monitoring, medical surveillance and training become mandatory. The California Department of Public Health (CDPH) is pushing for much stronger lead standards in the state. CDPH recommends reducing the PEL from 50 µg/m3 to below 10 µg/m3, and having workers removed from tasks causing lead exposure when BLLs reach between 20 and 30 µg/dL. They also created a bilingual video to raise awareness about the risks of lead poisoning on construction sites.

To find out more about preventing lead poisoning on your job site, order the LHSFNA’s Lead Poisoning Health Alert through the online Publications Catalogue at www.lhsfna.org or call the OSH Division at 202-628-5465. The LHSFNA also helped develop a guide, available at the Federal Highway Administration’s website, which details safe practices for bridge repair, renovation and demolition projects.

[Nick Fox]