Background: Regulatory monitoring data have been the exposure data resource most commonly applied to studies of the association between long-term PM_2.5 components and health. However, data collected for regulatory purposes may not be compatible with epidemiological studies.

Objectives: We studied three important features of the PM_2.5 component monitoring data to determine whether it would be appropriate to combine all available data from multiple sources for developing spatiotemporal prediction models in the National Particle Component and Toxicity (NPACT) study.

Methods: The NPACT monitoring data were collected in an extensive monitoring campaign targeting cohort participant residences. The regulatory monitoring data were obtained from the Chemical Speciation Network (CSN) and the Interagency Monitoring of Protected Visual Environments (IMPROVE). We performed exploratory analyses to examine features that could affect our approach to combining data: comprehensiveness of spatial coverage, comparability of analysis methods, and consistency in sampling protocols. In addition, we considered the viability of developing spatiotemporal prediction models given a ) all available data, b ) NPACT data only, and c ) NPACT data with temporal trends estimated from other pollutants.

Results: The number of CSN/IMPROVE monitors was limited in all study areas. The different laboratory analysis methods and sampling protocols resulted in incompatible measurements between networks. Given these features we determined that it was preferable to develop our spatiotemporal models using only the NPACT data and under simplifying assumptions.

Conclusions: Investigators conducting epidemiological studies of long-term PM_2.5 components need to be mindful of the features of the monitoring data and incorporate this understanding into the design of their monitoring campaigns and the development of their exposure prediction models.

Citation: Kim SY, Sheppard L, Larson TV, Kaufman JD, Vedal S. 2015. Combining PM_2.5 component data from multiple sources: data consistency and characteristics relevant to epidemiological analyses of predicted long-term exposures. Environ Health Perspect 123:651–658; http://dx.doi.org/10.1289/ehp.1307744

Address correspondence to S.-Y. Kim, Graduate School of Public Health & Institute of Health and Environment, Seoul National University, Room 717, Building 220, 1, Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea. Telephone: 82-2-880-2759. E-mail: puha0@snu.ac.kr

This work was supported primarily by the National Particle Component Toxicity (NPACT) initiative funded by the Health Effects Institute (HEI; 4749-RFA05), and by the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA) by the U.S. Environmental Protection Agency (EPA; RD 831697). Additional support was provided by the U.S. EPA (RD 83479601 and CR-834077101-0), by the National Institute of Environmental Health Sciences (NIEHS; P50 ES015915), and by the National Research Foundation of Korea (Basic Science Research Program, funded by the Ministry of Education: 2013R1A6A3A04059017).

Although this publication was developed under Science to Achieve Results (STAR) research assistance agreement RD831697 awarded by the U.S. EPA, it has not been formally reviewed by the U.S. EPA. The views expressed in this document are solely those of the University of Washington, and the U.S. EPA does not endorse any products or commercial services mentioned in this publication.

Received: 18 October 2013 Accepted: 24 February 2015 Advance Publication: 27 February 2015 Final Publication: 1 July 2015

Note to readers with disabilities: EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact ehp508@niehs.nih.gov . Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Note to readers with disabilities: EHP has provided a 508-conformant table of contents summarizing the Supplemental Material for this article (see below) so readers with disabilities may determine whether they wish to access the full, nonconformant Supplemental Material. If you need assistance accessing this or any other content on this site, please contact ehp508@niehs.nih.gov . Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Supplemental Table of Contents PDF (129 KB)