Metal mixtures in urban and rural populations in the US: The Multi-Ethnic Study of Atherosclerosis and the Strong Heart Study.

Abstract

BACKGROUND:

Natural and anthropogenic sources of metal exposure differ for urban and rural residents. We searched to identify patterns of metal mixtures which could suggest common environmental sources and/or metabolic pathways of different urinary metals, and compared metal-mixtures in two population-based studies from urban/sub-urban and rural/town areas in the US: the Multi-Ethnic Study of Atherosclerosis (MESA) and the Strong Heart Study (SHS).

METHODS:

We studied a random sample of 308 White, Black, Chinese-American, and Hispanic participants in MESA (2000-2002) and 277 American Indian participants in SHS (1998-2003). We used principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA) to evaluate nine urinary metals (antimony [Sb], arsenic [As], cadmium [Cd], lead [Pb], molybdenum [Mo], selenium [Se], tungsten [W], uranium [U] and zinc [Zn]). For arsenic, we used the sum of inorganic and methylated species (∑As).

RESULTS:

All nine urinary metals were higher in SHS compared to MESA participants. PCA and CA revealed the same patterns in SHS, suggesting 4 distinct principal components (PC) or clusters (∑As-U-W, Pb-Sb, Cd-Zn, Mo-Se). In MESA, CA showed 2 large clusters (∑As-Mo-Sb-U-W, Cd-Pb-Se-Zn), while PCA showed 4 PCs (Sb-U-W, Pb-Se-Zn, Cd-Mo, ∑As). LDA indicated that ∑As, U, W, and Zn were the most discriminant variables distinguishing MESA and SHS participants.

CONCLUSIONS:

In SHS, the ∑As-U-W cluster and PC might reflect groundwater contamination in rural areas, and the Cd-Zn cluster and PC could reflect common sources from meat products or metabolic interactions. Among the metals assayed, ∑As, U, W and Zn differed the most between MESA and SHS, possibly reflecting disproportionate exposure from drinking water and perhaps food in rural Native communities compared to urban communities around the US.

• Authors: Yuanjie Pang, Roger D Peng, Miranda R Jones, Kevin A Francesconi, Walter Goessler, Barbara V Howard, Jason G Umans, Lyle G Best, Eliseo Guallar, Wendy S Post, Joel D Kaufman, Dhananjay Vaidya, Ana Navas-Acien
• Journal: Environmental research (Environ Res) Vol. 147 Pg. 356-64 (May 2016) ISSN: 1096-0953 [Electronic] Netherlands
• PMID: 26945432 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2016 Elsevier Inc. All rights reserved.

Chemical References

• Uranium
• Arsenic
• Tungsten

Topics

• Aged
• Aged, 80 and over
• Arsenic (urine)
• Cluster Analysis
• Cohort Studies
• Environmental Exposure (analysis)
• Humans
• Indians, North American (statistics & numerical data)
• Middle Aged
• Principal Component Analysis
• Rural Population (statistics & numerical data)
• Tungsten (urine)
• United States
• Uranium (urine)
• Urban Population (statistics & numerical data)