Bai Heng, Capitanio John P, Miller Lisa A, Clougherty Jane E
Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
California National Primate Research Center, Davis, CA, USA.
Heliyon. 2021 Nov 9;7(11):e08333. doi: 10.1016/j.heliyon.2021.e08333. eCollection 2021 Nov.
Wildfire smoke (WFS) exposure is a growing threat to human health, and lower socioeconomic position (SEP) has been shown to increase pollution susceptibility. Studies of SEP-related susceptibility, however, are often compromised due to spatial confounding between lower-SEP and pollution. Here we examine outdoor-housed nonhuman primates, living in natural social hierarchy in a common location, born during years of high vs. low WFS, to examine the separate and combined effects of WFS and social rank, an analog to SEP, on lung and immune function.
Twenty-one females were born during extreme WFS events in summer 2008; 22 were born in summer 2009, during low WFS. Pulmonary function and circulating cytokines were measured three years later, in adolescence. We estimated fine particulate (PM) and ozone exposures during each animal's first 90 days and three years of age using regulatory data. Early-life social status was estimated using maternal rank at birth, as rank in females is relatively stable throughout life, and closely approximates mother's rank. We tested associations among WFS exposure, rank, and endpoints using linear regression and ANOVA.
Higher WFS exposure in infancy was, on average, associated with lower functional residual capacity (FRC), residual volume (RV), tissue compliance (Ct), and IL-8 secretion in adolescence. Higher social rank conferred significantly higher expiratory reserve volume (ERV) and functional residual capacity (FRC) among those born in the high-WFS year (2008). Differences in effects of rank between years were not significant after adjustment for multiple comparisons.
Exposure to WFS in infancy generally conferred adolescent respiratory volumes and inflammatory cytokines. Higher rank conferred higher respiratory volumes among females born during WFS, suggesting the possibility that the health benefits of rank may be more apparent under environmental challenge.
接触野火烟雾（WFS）对人类健康构成的威胁日益增大，且社会经济地位较低（SEP）已被证明会增加对污染的易感性。然而，由于低社会经济地位与污染之间存在空间混杂因素，与社会经济地位相关的易感性研究常常受到影响。在此，我们研究生活在同一地点、处于自然社会等级制度中的户外圈养非人灵长类动物，这些动物出生于WFS高发年与低发年，以探讨WFS和社会等级（类似于SEP）对肺和免疫功能的单独及联合影响。
21只雌性动物出生于2008年夏季的极端WFS事件期间；22只出生于2009年夏季，当时WFS水平较低。三年后，在青春期测量其肺功能和循环细胞因子。我们利用监管数据估算了每只动物出生后前90天和三岁时的细颗粒物（PM）和臭氧暴露量。利用出生时母体等级估算早期生活社会地位，因为雌性动物的等级在一生中相对稳定，且与母亲的等级非常接近。我们使用线性回归和方差分析测试WFS暴露、等级与终点之间的关联。
平均而言，婴儿期较高的WFS暴露与青春期较低的功能残气量（FRC）、残气量（RV）、组织顺应性（Ct）和白细胞介素-8分泌相关。在WFS高发年（2008年）出生的动物中，较高的社会等级赋予了显著更高的呼气储备量（ERV）和功能残气量（FRC）。在进行多重比较调整后，不同年份等级效应的差异不显著。
婴儿期接触WFS通常会影响青少年的呼吸容量和炎性细胞因子。在WFS期间出生的雌性动物中，较高的等级赋予了更高的呼吸容量，这表明在环境挑战下，等级带来的健康益处可能会更加明显。
