| Title | Screening Level Assessment of Arsenic and Lead Concentrations in Glass Beads Used in Pavement Markings |
|---|---|
| Record ID | 65826 |
| Personal Name Creator |
Boulanger, Bryan; Carlson, Paul J.; Fatkin, Harry; Raut Desai, Aditya B. |
| Corporate Creator | Texas Transportation Institute |
| Corporate Contributor |
United States. Department of Transportation. Federal Highway Administration. Office of Infrastructure Research and Development; United States. Department of Transportation. Federal Highway Administration. Turner-Fairbank Highway Research Center |
| Publisher | United States. Department of Transportation. Federal Highway Administration. Office of Infrastructure Research and Development |
| Publication Date | 20140101 |
| Language | English |
| Abstract | Retroreflective glass beads used in pavement markings are a critical component of highway safety. Glass beads meeting American Association of State Highway and Transportation Officials (AASHTO) M247 specifications are the current industry standard. AASHTO M247 glass beads are fabricated using reclaimed glass cullet, offering cost effective performance while beneficially reusing sources of industrial and commercial waste glass. However, reclaimed glass cullet may contain elevated levels of arsenic and lead that can be passed through to the final product. Concern regarding the presence of arsenic and lead in retroreflective glass bead products within the U.S. marketplace resulted in recently adopted legislation that sets a 200 part-per-million (ppm = 106 x massmetal/massbeads) limit for both arsenic and lead for beads used on U.S. roadways. While the scientific justification for the 200 ppm limit is not immediately clear, the proposed legislation is regarded as a good-faith attempt to limit the risk associated with the presence of arsenic and lead in the beads. This research developed a preliminary understanding of the risk associated with the presence of arsenic and lead in glass beads used in pavement marking systems to support decisionmaking. Researchers tested 15 samples of commercially available glass beads in current use on U.S. roadways from State transportation department stockpiles. The mean total concentration observed in the sampled beads across replicates was 71 ppm arsenic and 54 ppm lead. Extractable and bioaccessible arsenic levels in the beads were below instrument detection limits, and extractable and bioaccessible levels of lead in the beads were present at less than 3.6 ppm as a maximum mean value. Based on laboratory-generated characterization data, field investigations, available literature data, and the developed model, reasonably conservative screening levels for arsenic and lead in glass beads were determined to be 220 ppm and 580 ppm, respectively. Lead and arsenic levels observed in glass bead samples provided by State transportation departments were within the determined screening limits, indicating that currently available products pose minimal health risk while meeting retroreflective performance criteria. |
| Public Note | Distribution number: HRDS-10/01-14(WEB)E |
| Rosap ID | dot:38543 |
| Rosap URL | https://rosap.ntl.bts.gov/view/dot/38543 |
| TRT Terms | Road markings; Glass beads; Risk assessment |
| Geographical Coverage |
United States |
| TRIS Online Accession No |
1516331 |
| Contract Number | DTFH68-09-E-00105 |
| Report Number | FHWA-HRT-14-021 |
| Resource type | Tech Report |
| URL | https://ntlrepository.blob.core.windows.net/lib/65000/65800/65826/FHWA-HRT-14-021.pdf |
| Alternative URL | https://www.fhwa.dot.gov/publications/research/infrastructure/pavements/14021/index.cfm |
| Format | |
| Database | NTL Digital Repository |