Health and Safety Resource

​August-September 2017

The dangers of lead

 

Greek poet and physician Nicander of Colophon isn’t a household name today, but his interest in poisons in the mid-second century B.C. inspired him to write two poems on the subject: Theriaca and Alexipharmaca. These two poems also happen to be the oldest existing works available to us on substances that can make us sick or kill us.

Theriaca covers venomous snakes (including the elusive amphisbaena, which had a head at both ends of its body), spiders, and scorpions. Nicander’s remedy for snake bite, incidentally, was a balsam of the flesh of mating snakes, stag’s marrow, wax, rose, and olive oil applied to the skin.

Alexipharmaca leans more toward the vegetable and mineral poisons, but it also includes the earliest written observation of acute lead poisoning. Nicander described the effect as a frothing of the mouth, asperity of the tongue, and a dry throat accompanied by dry retching, chills, delusions, and overwhelming fatigue. The treatment? Nicander suggested various herbs and olive oil as an emetic to induce vomiting.

Today, we know more about lead’s etiology than we did two millennia ago, but, like the ancient Romans, who were the first people to use lead widely, we have a history of thinking that exposure to small doses of the metal poses no harm. The Roman Empire produced more than 80,000 metric tons of lead annually at its height and used the substance for everything from cooking utensils to plumbing. (By comparison, the U.S. produced 1.6 million metric tons of lead in 2012.) However, there is no concrete evidence that the effects of lead poisoning caused the fall of the Roman Empire.

Speaking of plumbing, lead pipes were also used throughout the United States in 1800s for making drinking water available; by 1900, more than 70 percent of cities with 30,000 or more residents were using lead-based products for conveying water because they were relatively cheap and easy to work with. Although the toxic effects of lead were known at the time, there was no concerted effort to ban lead plumbing until the 1920s.

corroded lead pipe coming out of external building wall

Lead may not have been the healthiest choice for conveying water, but it had many other consumer applications. The early 1920s also happened to mark the peak in sales of white lead pigments for interiors of American homes and the first commercial sales of leaded gasoline.

Of course, as we know now, those products proved to be unhealthful, too. Thanks, in part, to epidemiologist and pediatrician Philip J. Landrigan’s detailed studies of lead poisoning in children near ASARCO’s El Paso, Texas, smelting plant in the 1970s, the federal government enacted a number of laws that banned lead from gasoline, paint, water pipes, and food cans, and set exposure limits for workers. Average blood lead levels among U.S. adults fell from 13.1 micrograms per deciliter (μg/dL) between 1976 and 1980 to 1.09 micrograms per deciliter in 2012; there was a corresponding drop in blood lead levels of American children as well. The result was one of this country’s most significant public health achievements in the past 50 years.

vial of blood for lead level test

Even with that good news, however, lead has become entrenched in our infrastructure and virtually every other aspect of our – and our children’s – lives. Lead’s legacy will remain with us for some time to come, even if we eliminated all of our possible exposure sources today.

Among children, lead poisoning is still a chronic environmental hazard. The Centers for Disease Control and Prevention estimates​ that at least 4 million households have children ages 1 to 5 with blood lead levels above five micrograms per deciliter, the reference level that the CDC recommends public health actions be initiated. And serious cases of lead poisoning still appear in hospital emergency rooms, clinics, and physician​s’ offices. In children, no developing organ is immune to the effects of lead poisoning.

​Read more about Childhood lead poisoning in Oregon

Possible sources of lead

Occupation

  • Painters
  • Home remodelers/renovators
  • Construction/demolition workers
  • Bridge maintenance/repair
  • Auto body repairers/painters
  • Battery manufacturers/recyclers
  • Radiator repairers/manufacturers
  • Furniture refinishers
  • Plumbers, pipe fitters
  • Roofers
  • Lead miners, smelters, and refiners
  • Glass, copper, and brass manufacturers
  • Boat builders/painters/repair/maintenance
  • Ceramics making/glaze mixing
  • Printers (ink)
  • Plastic and rubber manufacturers
  • Police officers
  • firing range instructors
  • Steel welders or cutters
  • Jewelry-making
  • Gas station attendants
  • Aircraft repair
  • X-ray shield/film radiology

Hobbies and related activities

  • Home remodeling/renovation
  • Car or boat repair
  • Glazing/making pottery
  • Reloading/target shooting at firing ranges
  • Furniture refinishing
  • Making/handling lead shot and fishing weights/sinkers
  • Using lead soldering/welding
  • Oil painting (artistic)
  • Using pastel art pencils
  • Making stained glass
  • Jewelry making
  • Using/making diving and exercise weights
  • Repairing old painted wooden or metal toys

Ingested sources

  • Traditional/home remedies such as Azarcon, Greta, Pay-loo-ah, Kohl, Ayurvedic
  • Imported candy and candy wrappers
  • Supplements (calcium)

Environmental/other

  • Lead-based paint (pre-1978)
  • Soil/dust near lead industries, roadways, lead-painted houses
  • Plumbing and solder
  • Cosmetics and hair dye
  • Imported vinyl mini-blinds
  • Imported ceramic tiles for the kitchen/bathroom
  • Building materials: Gutters, flashing, tile, window glazing
  • Ceramic ware/glazed pottery
  • Porcelain bathtubs
  • Leaded glass/pewter
  • Leaded gasoline (race, collector cars)
  • Soldered seams-imported canned food
  • Soldered copper pipes
  • Submersible pumps in wells
  • Brass plumbing fixtures
  • Bronze, pewter, leaded crystal
  • Electronics manufacturers
  • Pesticides
  • Imported crayons
  • Storage batteries
  • Plastic insulation on electrical wiring and old telephone wiring
  • Candle wicks
 

Those potential exposures could be the source of long-term medical issues ranging from an increased risk of high blood pressure and heart disease to kidney and immune system disorders among those who were exposed to the lead on the job or to lead in the soil, air, and buildings that were constructed when lead paint was still in use. And lead absorbed in human bones for years can leak back into the blood in small increments as people age and lose bone density. 

Those currently working in such industries as metal smelting, lead-battery manufacturing, and building renovation are likely absorbing too much lead unless they are protecting themselves. 

According to the National Institute for Occupation Safety and Health, blood lead levels as low as five micrograms per deciliter are associated with decreased renal function and blood lead levels at 10 micrograms per deciliter are associated with an in reased risk of hypertension, yet many thousands of workers still have levels exceeding 10 micrograms per deciliter. (Infographic 2, Blood lead levels.) Although the exposure limits in federal OSHA’s lead rules are not likely to change in the near future, Oregon OSHA, Washington, and California are considering state-initiated rules that would set lower limits on occupational exposures.

infographic on lead levels, Estimated prevalence rates for workers with elevated blood lead levels


At the nation's workplaces, federal OSHA estimates​​ that

804,000 workers
in general industry and an additional

838,000 workers
in construction are potentially exposed to lead.

Why is lead so bad?

When lead gets into your body, it generates a free radical called reactive oxygen species (ROS); it’s an unstable molecule that contains oxygen and that easily reacts with other molecules in a cell. A buildup of ROS in your cells can damage your DNA and RNA and may cause cell death. 

Lead also disarms glutathione, which is a simple molecule that is critical in helping your body prevent disease and fight infections. 

Lead follows a path through your blood vessels and quickly binds to red blood cells and diffuses into your soft tissues, including the kidneys, brain, liver, bone marrow, and bone, where it is stored for decades. That’s why you can be exposed to lead for years and not have any symptoms. But the more you are exposed, the greater your risk of eventually showing symptoms and being poisoned. 

Lead also affects the developing brain in many ways, all of which are bad, including delayed or reversed development, permanent learning disabilities, seizures, coma, and even death. Children who are exposed to lead during their first two or three years of life are the most likely to suffer long-term learning and cognitive damage. That’s why lead exposure is most dangerous for children younger than 6 years old. 

Workers who are exposed to high levels of lead risk long-term health problems and must be carefully monitored. Symptoms usually build up slowly from repeated exposure to small amounts of lead.

 

How to know if you are exposed to lead

There are essentially two ways you can be exposed to lead. You can breathe lead dust or fumes or you can swallow lead if it gets on your hands or face or in your food. You can also contaminate your children if you are exposed to lead dust at work and you don’t wash or change your clothes before you come home. Lead (II,IV) oxide, or red lead – used as a pigment primer for iron and is a component of lead glass – can be absorbed through the skin in high concentrations.

Symptoms of lead exposure include tiredness, irritability, nausea, headache, stomach aches or pains, and loss of appetite, but many people who have been exposed show no symptoms at all. If you think you have been exposed to lead, the best way to find out is to have your blood tested; tell your doctor, even if you don’t have symptoms. 

Does your employer have to protect you from lead?

Your employer is responsible for determining if you are overexposed to lead at your workplace and for protecting you. If your exposure is more than what is called the action level – 30 micrograms per cubic meter of air (30 μg/m3) averaged over an eight-hour period – your employer must comply with specific Oregon OSHA requirements to limit your exposure. Current Oregon OSHA rules prohibit workers from being exposed to more than 50 micrograms of lead per cubic meter of air (50 μg/m3) averaged over an eight-hour period – called the permissible exposure limit or PEL. (Infographic 3 – Rule violations)

Where to find more information about lead

Lead as a public health issue

Lead in the workplace

 
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