Worker Health Study Summaries
Research on long-term exposure
Children of California’s Lead-Exposed Construction Workers (Lead Exposure)
NIOSH studied lead exposure among children of lead-exposed construction workers.
Why NIOSH did the study
Small increases in blood lead levels in children can increase their risk of having behavior problems or being a slow learner.
Lead-exposed construction workers may bring lead home from work on their clothing and hands. If they bring lead home on their clothing and hands, then their homes and cars may have increased lead levels. As a result, the young children of lead-exposed workers may have higher blood lead levels than children of non-exposed control workers.
The purpose of the study was to determine if the children of lead exposed workers had higher blood lead levels compared to control workers’ children. We also wanted to know if the homes and cars of lead-exposed workers had higher lead levels than control workers.
How NIOSH and NJDOH did the study
NIOSH and the New Jersey Department of Health contacted all construction workers in New Jersey who had had a report of a blood lead level above 25 micrograms per deciliter (µg/dL) in 1994.
The workers had to meet the following requirements.
- They had to have worked in construction for at least a month in the prior year.
- They had to be living at home while working in construction.
- They had to have at least one child between 9 months and 6 years old.
We asked these workers to provide the names of 1 or 2 neighbors who might serve as non-exposed controls for our study. The controls were not exposed to lead at work and had at least one child between 9 months and 6 years of age.
We asked the care giver of each household about sources of lead in the home and the ages of the children. We also asked the worker about his work habits.
We collected blood from the workers and children who were between 9 months and 6 years of age. We report the amount of lead in micrograms per deciliter (µg/dL) blood. A deciliter is a little less than half a cup.
We took dust and surface wipe samples for lead tests in the family room, child’s bedroom and the entrance to the house. We also collected dust and wipes samples from the area of the home where the worker changed his clothing and in the laundry area.
We took dust samples from the seat and floor of the car with a special vacuum cleaner. We collected wipe samples for lead levels from the driver and passenger side arm rests and the steering wheel.
We reported lead levels in dust in parts of lead per million parts (ppm) of dust. We reported the amount of lead in the wipe samples in micrograms of lead per square meter (µg/m2) of surface wiped.
We compared the percentage of children of lead-exposed workers who had blood lead levels above 10 µg/dL with the percentage in control households.
We chose 10 µg/dL because the Centers for Disease Control and Prevention recommends that children’s blood lead levels be kept below this level.
Children of lead-exposed workers were 6 times more likely to have elevated blood lead levels (above 10 µg/dL) than were the children of control workers. Eight of 31 children of lead-exposed workers had elevated blood lead levels. However, only one of 19 children of control workers had an elevated blood lead level. The average lead levels on the hands of exposed workers was 7 times higher than on the hands of control workers.
The lead levels were higher in the cars of exposed workers than in the cars of control workers (see Table 1).
The homes of exposed workers had higher lead levels than control workers’ homes (see Table 2).
Table 1. Surface Lead Levels in Automobiles
|Area of the Car||Exposed Average||Controls Average|
|Driver’s Floor||990 ppm||250 ppm|
|Driver’s Seat||2000 ppm||450 ppm|
|Driver’s Armrest||2000 µg/m2||190 µg/m2|
|Passenger’s Floor||900 ppm||260 ppm|
|Passenger’s Seat||1700 ppm||220 ppm|
|Passenger’s Armrest||1200 µg/m2||120 µg/m2|
|Steering Wheel||240 µg/m2||41 µg/m2|
Table 2. Lead Levels in the Homes
|Area of the Home||Exposed Average||Controls Average|
|Main Entry Exterior Room||640 ppm||330 ppm|
|Main Entry Exterior Floor||350 ppm||470 ppm|
|Changing Area Floor||370 ppm||120 ppm|
|Laundry Room Floor||530 ppm||290 ppm|
|Laundry Room Washing Machine||72 µg/m2||38 µg/m2|
|Family Room Floor||250 ppm||150 ppm|
|Family Room Window Sill||360 µg/m2||460 µg/m2|
|Family Room Sofa||340 ppm||172 ppm|
|Children’s Bedroom Floor||220 ppm||110 ppm|
|Children’s Bedroom Window Sill||450 µg/m2||370 µg/m2|
The blood lead levels of the children of exposed workers were strongly related to the lead levels on the driver’s seat of the car, the family room carpet and furniture, the changing area carpet, and the child’s bedroom carpet. This means that the higher the lead levels in these areas the more likely the child’s blood lead level was to be elevated. This was not true of children of control workers.
The study suggests that exposed workers brought lead home with them. Lead that was on their clothing and skin may have been transferred to their cars and homes.
If you are exposed to lead at work, you can protect your children by following the suggestions in the fact sheet, “Protecting Workers’ Families From Lead Exposure. ”
For more information please call the NIOSH toll-free number at 800-356-4674.
Can Working With Lead Harm Children?
Workers exposed to lead on the job may leave work with lead dust on their hands and clothing. This lead may get into their cars and homes.
The number of days that a worker is exposed to lead is important. Workers with regular exposure to lead may place their children at higher risk.
Small children may put their hands on floors and other surfaces that have lead on them and then put their hands in their mouths.
Children who swallow lead dust may have problems learning and paying attention. Lead can harm the brain, nerves and kidneys. Lead is especially dangerous for children under six years of age.
Most children with lead poisoning do not look or act sick. The only way to know if a child has lead poisoning is to do a blood test. Blood lead tests are available through a doctor or the local health department.
Children of lead-exposed workers should have blood lead tests done more frequently than other children. Children with blood lead levels below 10 microgram (µg)/deciliter (dL) should be retested every six months. Those with blood lead levels between 10 and 14 µg/dL should be retested every three months. Children with blood lead levels above 15 µg/dL need to be treated at a special lead treatment center or by a doctor experienced in treating children with elevated blood lead levels.
If a child of a lead-exposed worker has a blood lead level above 10 µg/dL, workers should have their homes and if possible their cars tested for lead. Workers should make certain there are no other sources of lead in their homes, such as solder or paint chips, that may be affecting their children.
How can workers and employers protect workers families from lead poisoning?
Every construction workplace where a worker is exposed to lead is covered by the Occupational Safety and Health Administration (OSHA) Construction Lead Standard.
Certain OSHA rules apply to workers exposed to more than 50 µg of lead per cubic meter (m3) of air over a work day. These rules state that the employer must:
- Provide clean protective work clothing at least once a week. If lead exposure is above 200 µg/m3, employers must provide clean clothing daily. The employer must have work clothing laundered.
- Provide clean change areas and require that workers change into clean clothes and shoes before they leave work. Any protective clothing or equipment that is required to be worn during the work shift may not leave the worksite.
- Provide separated lockers for storage of street clothes and shoes and work clothes. Lockers used for street clothes should never be used for work clothes.
- Provide lunchrooms or eating areas that are not contaminated with lead.
- Provide handwashing stations. Workers must wash their hands and face before eating, drinking, smoking or applying cosmetics. Workers must either change their work clothing or vacuum off their clothing before eating.
- Provide showers if possible. Where showers are provided, the worker must shower at the end of the work shift. If showers are not provided, employers must be sure that workers wash their face and hands before they leave the work site.
In addition to the rules specified in the OSHA lead standard, we recommend that lead-exposed workers who cannot shower before leaving work, shower and wash their hair as soon as they get home.
NIOSH conducted a study of a bridge repair site that included workers with lead exposures both below and above 50 µg /m3 of air. We found that even workers with low exposures to lead (below 50 µg/m3 of air) had high lead levels in their cars and homes. This suggests that workers with low lead exposures may reduce lead exposure to their families by following the rules from the OSHA standard where possible.
If you are exposed to lead and your employer does not launder your clothing, you should take the clothing home in a plastic bag and put the clothing directly into the washing machine. You should use detergents to remove lead. Other clothing should not be washed with the work clothing. After clothes are washed, the empty machine should be run through the wash cycle to remove any lead dust.
Cleaning Your Car and Home
It is better to prevent lead contamination than to remove it. In addition to the recommendations to change clothes and shower before leaving work, close the windows of your car at work to protect the inside from lead dust in the air.
It is very difficult to remove lead dust from upholstery and carpets. Limit your child’s contact with lead-contaminated upholstery, carpets and cars. If possible, replace lead contaminated stuffed furniture and carpets in the rooms where your children play.
Workers may follow these steps to remove the lead dust from homes and cars:
- A high efficiency particulate (HEPA) vacuum cleaner removes lead dust without blowing it into the air. Employers should buy or rent a HEPA vacuum cleaner so employees can remove lead dust from their homes and cars.
- Washable surfaces in the cars and homes of workers should be washed with detergents to remove lead dust.
Always remember that the most important way to protect children from lead poisoning is to not get lead dust in your car or home in the first place.
Other measures that can help protect children from lead poisoning are:
- Keep children from chewing on painted surfaces or eating paint chips.
- Children should eat regular meals and foods high in calcium and iron, like fortified cereals, greens, milk, yogurt and cheese.
Piacitelli G, Whelan E (Nov., 1996). Keeping lead at work. Journal of Protective Coatings and Linings.
New Jersey Department of Health. Important information for contractors and workers about Lead Paint Hazards. G4497.