Return to the Table of ContentsProtecting Workers Exposed to Lead-based Paint Hazards
A Report to Congress
DHHS (NIOSH) PUBLICATION NO. 98-112
JANUARY 1997
Chapter 3
LEAD EXPOSURE OF WORKERS' FAMILIES
Recent NIOSH Research
Review of Previous Studies
Summary and Recommendations
References
Families of construction workers, including those involved in LBP activities, may be exposed to lead brought home from the workplace. NIOSH and the New Jersey Department of Health conducted a surveillance study in 1993 and 1994 involving the voluntary participation of 46 construction workers' families. The workers, who had reported BLLs greater than or equal to 25 µg/dL, were identified from the 510 construction workers in the New Jersey ABLES registry. BLL testing of young children indicated that the workers' children, particularly those under age six, were at greater risk of having elevated BLLs (greater than or equal to 10 µg/dL) than children in the general population (Table 3.1). Higher percentages of workers' children in age categories one-to-two and three-to-five years had elevated BLLs than national averages for these ages. Limitations of this study were that BLL data for worker's children were compared to national averages, not local controls, and no environmental lead measurements were made in workers' homes.
| Age (years) |
NJ workers' families percent greater than or equal to 10 µg/dL |
U.S. population* percent greater than or equal to 10 µg/dL |
|---|---|---|
| 1 – 2 | 40 | 11.5 |
| 3 – 5 | 24.0 | 7.3 |
| 6 – 11 | 6.5 | 4.0 |
To address these limitations NIOSH collaborated with the New Jersey Department of Health to conduct a more comprehensive study of take-home lead exposures in the construction industry. NIOSH investigators assessed environmental lead exposures in the homes of lead-exposed construction workers from the ABLES registry and in the homes of controls (unexposed neighbor families). Environmental sampling was done in 37 exposed workers' homes and 22 neighborhood control homes; of these, 29 exposed and 18 control families also participated in BLL testing.
The children of lead-exposed construction workers were more likely to have elevated BLLs than their neighbors' children. Thirty-one workers' children (26 percent) had elevated BLLs greater than or equal to 10 µg/dL compared with 19 of the neighbors' children (5 percent) (unadjusted odds ratio = 6.1, 95% confidence interval, 0.9 to 147.2)2. The environmental evaluation suggests that the construction workers' occupational lead exposures combined with ineffective hygiene practices resulted in lead contamination of their cars and homes3. Significantly higher surface lead levels were found in workers' cars on the driver's floor (geometric mean [GM] = 1100 micrograms per square meter [µg/m2]) than in the control group (250 µg/m2). Surface lead levels were generally higher in workers' homes; the average interior entry floor lead level was 23 µg/m2 in workers'homes and 9 µg/m2 in control homes (p = .08). The lead concentrations (which are not affected by housekeeping) in surface dust collected in clothing change rooms were significantly higher in workers' homes (GM = 370 parts per million [ppm]) than in control homes (120 ppm), p = .005. The lead loadings measured on window sills, which in older homes are often due to LBP on window friction surfaces, were not different in exposed and control homes.
In 1993, NIOSH evaluated lead contamination at a Connecticut highway bridge renovation project. Prior to repainting, LBP was removed from the structure by abrasive blasting with recycled steel grit. The blasting took place inside a tarpaulin containment using ventilation to maintain negative air pressure. NIOSH found lead contamination on the hands, faces, and clothing of the 25 workers sampled at this construction site4. Additionally, lead dust was present in each of the 27 workers' automobiles sampled5. Relatively high surface lead loadings were found on the driver's side floors (GM = 1900 µg/m2), armrests (1100 µg/m2), and steering wheels (240 µg/m2), suggesting that workers carried the lead into their cars on hands and clothing. Interestingly, workers with low airborne exposures to lead had higher lead levels in their vehicles. There was no unexposed control group in this study, but in a related study described above, the lead levels on the floors of the drivers' sides of vehicles were only 250 µg/m2. Workers who were highly exposed to airborne lead, such as blasters, regularly wore protective clothing, changed out of work clothing, and showered before entering their cars. Other workers, including industrial hygiene and safety specialists, who had low airborne exposures to lead, did not regularly follow the same occupational hygiene practices, presumably because they were not felt to be necessary.
There is also potential for take-home lead exposures among families of renovation and remodeling workers. A NIOSH study of lead-exposed residential renovation and repair workers found higher surface lead levels in 20 full-time workers' vehicles (arithmetic mean: 3300 µg/m2) than in those of 11 part-time volunteers (1500 µg/m2), although the difference did not reach statistical significance. 6
Exposure to lead in construction activities can result in workers' vehicles being contaminated and a significant amount of lead being transported into the home.
As required by the Workers' Family Protection Act of 1992 (29 U.S.C. 671a), NIOSH prepared a comprehensive report to Congress documenting incidents of para-occupational or "take-home" exposure to toxic substances, for the purposes of developing a strategy to reduce such exposures7.
The report documents that, in a variety of industries, lead dust may be carried on skin and clothing from the workplace to homes and vehicles, resulting in take-home lead exposures among the workers' families. Children of lead-exposed workers may be exposed to higher levels of lead when there are ineffective occupational hygiene facilities or practices in the workplace. A study of lead storage battery workers showed statistically significant differences in BLLs between children of workers with effective hygiene practices (e.g., showering and changing clothes before leaving work) and children of workers with ineffective hygiene practices8. The study recommended the employer provide more stringent enforcement of lead containment practices. The industries for which take-home lead exposure has been most frequently reported include lead smelting, battery manufacturing/recycling, radiator repair, electrical components manufacturing, pottery/ceramics production, and stained glass making. Take-home lead exposures for the construction industry have only recently been reported. This may be the result of increasing attention on construction industry lead exposures in the 1990s.
In that report to Congress, NIOSH identified 64 investigations worldwide of take-home lead exposure where children's BLLs were measured.7 Twenty-two were published studies for cohorts of lead-exposed workers in general industry. Researchers found in the majority of the studies that the workers' children had significantly higher BLLs than children in the control groups. The mean BLLs for children of lead-exposed workers across all the cohort studies ranged from 10.2 to 81 µg/dL, while those for children in control groups ranged from 6.2 to 27 µg/dL.
Children of construction workers with elevated BLLs (range: 10 to 28 µg/dL) were reported in five case series or case reports. Industrial hygiene assessments of construction workers in this report were consistent with the BLL findings: high surface lead levels were found on workers' skin and clothing, in their vehicles, or in their homes.7
Families of bridge workers, residential renovation and remodeling workers, and others involved in LBP activities may have take-home lead exposures as a result of lead dust brought home from the workplace on skin and clothing. Research is needed to determine better the extent of take- home lead exposures among workers who are exposed to low airborne lead levels, but who work in lead-contaminated environments. Until more data are available, protective clothing and hygiene facilities should be considered for workers frequently exposed to lead in lead-contaminated workplaces, even for those workers whose average exposures are below the OSHA PEL. It is the responsibility of employers to provide good hygiene facilities and encourage their use. Both employers and workers need to make sure that good hygiene practices are followed to prevent take-home lead exposures.