marlod: an R Package to Model Environmental Exposure and Biomonitoring Data With Repeated Measurements and Values Below the Limit of Detection.

Details

• Alternative Title:
  Journal of Exposure Science & Environmental Epidemiology, 2025, v. 35, no. 4: marlod: an R Package to Model Environmental Exposure and Biomonitoring Data With Repeated Measurements and Values Below the Limit of Detection.
• Journal Article:
  Journal of Exposure Science & Environmental Epidemiology
• Personal Author:
  Chen, I-Chen
• Description:
  In environmental and occupational research, when concentration measurements are taken from the same individual or study site, they are considered to be repeated measurements. Furthermore, when these samples fall below the limit of detection (LOD) of laboratory instruments, they are referred to as left-censored repeated measures data. These unquantified measurements typically represent low-level concentrations between zero and the LOD. There is an increasing need for statistical models that can effectively analyze left-censored environmental exposure and biomonitoring data with repeated measures, particularly among industrial hygienists. This is due to the growing importance of estimating the impact of exposure on disease risk and understanding the variability in occupational exposure both within and between workers. Analytical results from laboratories, including data on environmental contaminants (e.g., from hand wipes or personal breathing zone air samples) and occupational exposures (e.g., from biological media such as urine or serum) are often subject to non-detectable concentrations and tend to exhibit right-skewed distributions. The statistical modeling of exposure data that contain both repeated samples and samples below the LOD can be complex.
• Content Notes:
  Author manuscript
• Subjects:
  • Humans
  • Biological Monitoring
  • Laboratories
  • Limit of Detection
  • Urine
  • Occupational Exposure
  • Models, Statistical
• Keywords:
  • Marginal analysis
  • Left censoring
  • Right skewness
  • Limit of detection
  • Repeated measures
• Source:
  Journal of Exposure Science & Environmental Epidemiology, 2025, v. 35, no. 4
• DOI:
  https://doi.org/10.1038/s41370-025-00752-8
• ISSN:
  1559-0631 ; 1559-064X
• Pubmed ID:
  39875597
• Pubmed Central ID:
  PMC12234243
• Document Type:
  Text
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/
• Genre:
  Journal Article
• Pages in Document:
  630-631 (3 pdf pages)
• Volume:
  35
• Issue:
  4
• Download URL:
  https://stacks.cdc.gov/view/cdc/261727/cdc_261727_DS1.pdf
• File Type:
  [PDF - 284.31 KB]
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:69d8e7675591b064f3d4bbb218d3f21cdf057e76be02cee3f598010691610b0a27fd87728e74b0267054915ae6fccb9d1c12847c521736d1c0268cc4dd9ebf56