title: Low-level mercury in children: associations with sleep duration and cytokines TNF-α and IL-6.
abstract: There is a sizeable literature suggesting that mercury (Hg) exposure affects cytokine levels in humans. In addition to their signaling role in the immune system, some cytokines are also integrally associated with sleep behavior. In this cross-sectional study of 9-11 year old children (N=100), we measured total blood Hg in whole blood, serum levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), and objectively measured sleep and activity using actigraphy. Increasing blood Hg was associated with significantly shorter sleep duration and lower levels of TNF-α. IL-6 was not associated with sleep or blood Hg. This study is the first to document an association between total blood Hg and sleep (albeit a small effect), and the first to consider the associations of total blood Hg with cytokines TNF-α and IL-6 in a pediatric sample. Further research using alternative designs (e.g., time-series) is necessary to determine if there is a causal pathway linking low-level Hg exposure to sleep restriction and reduced cytokines.
authors.affiliation: Department of Public Health, Food Studies, and Nutrition, Syracuse University, United States. Electronic address: bbgump@syr.edu.
authors.forename: Brooks B
authors.initials: BB
authors.lastname: Gump
authors.affiliation: Departments of Biological Sciences, State University of New York College at Oswego, United States.
authors.forename: Elena
authors.initials: E
authors.lastname: Gabrikova
authors.affiliation: Departments of Chemistry, State University of New York College at Oswego, United States.
authors.forename: Kestutis
authors.initials: K
authors.lastname: Bendinskas
authors.affiliation: Department of Public Health, Food Studies, and Nutrition, Syracuse University, United States.
authors.forename: Amy K
authors.initials: AK
authors.lastname: Dumas
authors.affiliation: Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, United States; Department of Environmental Health Sciences, School of Public Health, The University at Albany, United States.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Palmer
authors.affiliation: Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, United States; Department of Environmental Health Sciences, School of Public Health, The University at Albany, United States.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Parsons
authors.affiliation: Departments of Biological Sciences, State University of New York College at Oswego, United States.
authors.forename: James A
authors.initials: JA
authors.lastname: MacKenzie
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008628:Mercury / Q000633:toxicity*; D012890:Sleep / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D008628:Mercury
keywords: Children; Cytokines; IL-6; Mercury; Sleep; TNF-α