Association between global DNA methylation (LINE-1) and occupational particulate matter exposure among informal electronic-waste recyclers in Ghana

ABSTRACT

This study examined the associations between PM (2.5 and 10) and global DNA methylation among 100 e-waste workers and 51 non-e-waste workers serving as controls. Long interspersed nucleotide repetitive elements-1 (LINE-1) was measured by pyrosequencing. Personal PM_2.5 and PM₁₀ were measured over a 4-hour work-shift using real-time particulate monitors incorporated into a backpack . Linear regression models were used to assess the association between PM and LINE-1 DNA methylation. The concentrations of PM_2.5 and PM₁₀ were significantly higher among the e-waste workers than the controls (77.32 vs 34.88, p < 0.001 and 210.21 vs 121.92, p < 0.001, respectively). PM_2.5 exposure was associated with increased LINE-1 CpG2 DNA methylation (β = 0.003; 95% CI; 0.001, 0.006; p = 0.022) but not with the average of all 4 CpG sites of LINE-1. In summary, high levels of PM_2.5 exposure was associated with increased levels of global DNA methylation in a site-specific manner.

KEYWORDS:

• DNA methylation
• LINE-1
• PM_2.5
• PM₁₀
• e-waste
• e-waste workers

Acknowledgments

The authors wish to thank all the study participants and the supporting staff of the GEOHealth II project. The authors also acknowledge the University of Michigan sequencing core for running the LINE-1 pyrosequencing. Pre-Publication Support Service (PREPSS) supported the development of this manuscript by providing pre-publication peer-review and copy editing.

Disclosure Statement

The authors declare no conflict of interest.

Additional information

Funding

This research was supported by the ½ West Africa-Michigan CHARTER in GEO-Health with funding from the United States National Institutes of Health/Fogarty International Center (US NIH/FIC) (paired grant no 1U2RTW010110-01/5U01TW010101) and Canada’s International Development Research Center (IDRC) (grant no. 108121-001);United States National Institutes of Health/Fogarty International Center [1U2RTW010110-01/5U01TW010101];Canada’s International Development Research Center [108121-001].