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Fang, Shona C

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Fang

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Shona C

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Fang, Shona C
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Now showing 1 - 10 of 14
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    Changes in Tobacco Smoke Exposure following the Institution of a Smoke-Free Policy in the Boston Housing Authority
    (Public Library of Science, 2015) Levy, Douglas; Adamkiewicz, Gary; Rigotti, Nancy; Fang, Shona C; Winickoff, Jonathan
    Introduction: To protect residents from tobacco smoke exposure (TSE), the Boston Housing Authority (BHA) prohibited smoking in BHA-owned apartments beginning in 2012. Our goal was to determine if the smoke-free policy reduced TSE for non-smoking BHA residents. Methods: We compared TSE before the smoke-free policy (2012) and one year later among BHA residents as well as residents of the neighboring Cambridge Housing Authority (CHA) where no such policy was in place. Participants were a convenience sample of adult non-smoking BHA and CHA residents cohabitating with only non-smokers. Main outcomes were 7-day airborne nicotine in participants’ apartments; residents’ saliva cotinine; and residents’ self-reported TSE. Results: We enrolled 287 confirmed non-smokers (192 BHA, 95 CHA). Seventy-nine percent (229) were assessed at follow-up. At baseline, apartment and resident TSE were high in both housing authorities (detectable airborne nicotine: 46% BHA, 48% CHA; detectable saliva cotinine: 49% BHA, 70% CHA). At follow-up there were significant but similar declines in nicotine in both sites (detectable: -33% BHA, -39% CHA, p = 0.40). Detectable cotinine rose among BHA residents while declining among CHA participants (+17% BHA vs. -13% CHA, p = 0.002). Resident self-reported TSE within and outside of the housing environment decreased similarly for both BHA and CHA residents. Conclusions: Apartment air nicotine decreased after the introduction of the smoke-free policy, though the decline may not have resulted from the policy. The BHA policy did not result in reduced individual-level TSE. Unmeasured sources of non-residential TSE may have contributed to BHA residents’ cotinine levels.
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    A panel study of occupational exposure to fine particulate matter and changes in DNA methylation over a single workday and years worked in boilermaker welders
    (BioMed Central, 2013) Kile, Molly L; Fang, Shona C; Baccarelli, Andrea A; Tarantini, Letizia; Cavallari, Jennifer; Christiani, David
    Background: Exposure to pollutants including metals and particulate air pollution can alter DNA methylation. Yet little is known about intra-individual changes in DNA methylation over time in relationship to environmental exposures. Therefore, we evaluated the effects of acute- and chronic metal-rich PM2.5 exposures on DNA methylation. Methods: Thirty-eight male boilermaker welders participated in a panel study for a total of 54 person days. Whole blood was collected prior to any welding activities (pre-shift) and immediately after the exposure period (post-shift). The percentage of methylated cytosines (%mC) in LINE-1, Alu, and inducible nitric oxide synthase gene (iNOS) were quantified using pyrosequencing. Personal PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 μm) was measured over the work-shift. A questionnaire assessed job history and years worked as a boilermaker. Linear mixed models with repeated measures evaluated associations between DNA methylation, PM2.5 concentration (acute exposure), and years worked as a boilermaker (chronic exposure). Results: PM2.5 exposure was associated with increased methylation in the promoter region of the iNOS gene (β = 0.25, SE: 0.11, p-value = 0.04). Additionally, the number of years worked as a boilermaker was associated with increased iNOS methylation (β = 0.03, SE: 0.01, p-value = 0.03). No associations were observed for Alu or LINE-1. Conclusions: Acute and chronic exposure to PM2.5 generated from welding activities was associated with a modest change in DNA methylation of the iNOS gene. Future studies are needed to confirm this association and determine if the observed small increase in iNOS methylation are associated with changes in NO production or any adverse health effect.
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    The Relationship between Inflammatory Biomarkers and Telomere Length in an Occupational Prospective Cohort Study
    (Public Library of Science, 2014) Wong, Jason; De Vivo, Immaculata; Lin, Xihong; Fang, Shona C; Christiani, David
    Background: Chronic inflammation from recurring trauma is an underlying pathophysiological basis of numerous diseases. Furthermore, it may result in cell death, scarring, fibrosis, and loss of tissue function. In states of inflammation, subsequent increases in oxidative stress and cellular division may lead to the accelerated erosion of telomeres, crucial genomic structures which protect chromosomes from decay. However, the association between plasma inflammatory marker concentrations and telomere length has been inconsistent in previous studies. Objective: The purpose of this study was to determine the longitudinal association between telomere length and plasma inflammatory biomarker concentrations including: CRP, SAA, sICAM-1, sVCAM-1, VEGF, TNF-α, IL-1β, IL-2, IL-6, IL-8, and IL-10. Methods: The longitudinal study population consisted of 87 subjects. The follow-up period was approximately 2 years. Plasma inflammatory biomarker concentrations were assessed using highly sensitive electrochemiluminescent assays. Leukocyte relative telomere length was assessed using Real-Time qPCR. Linear mixed effects regression models were used to analyze the association between repeated-measurements of relative telomere length as the outcome and each inflammatory biomarker concentration as continuous exposures separately. The analyses controlled for major potential confounders and white blood cell differentials. Results: At any follow-up time, each incremental ng/mL increase in plasma CRP concentration was associated with a decrease in telomere length of −2.6×10−2 (95%CI: −4.3×10−2, −8.2×10−3, p = 0.004) units. Similarly, the estimate for the negative linear association between SAA and telomere length was −2.6×10−2 (95%CI:−4.5×10−2, −6.1×10−3, p = 0.011). No statistically significant associations were observed between telomere length and plasma concentrations of pro-inflammatory interleukins, TNF-α, and VEGF. Conclusions: Findings from this study suggest that increased systemic inflammation, consistent with vascular injury, is associated with decreased leukocyte telomere length.
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    Secondhand tobacco smoke exposure and heart rate variability and inflammation among non-smoking construction workers: a repeated measures study
    (BioMed Central, 2013) Zhang, Jinming; Fang, Shona C; Mittleman, Murray; Christiani, David; Cavallari, Jennifer M
    Background: Although it has been well recognized that exposure to secondhand tobacco smoke (SHS) is associated with cardiovascular mortality, the mechanisms and time course by which SHS exposure may lead to cardiovascular effects are still being explored. Methods: Non-smoking workers were recruited from a local union and monitored inside a union hall while exposed to SHS over approximately 6 hours. Participants were fitted with a continuous electrocardiographic monitor upon enrollment which was removed at the end of a 24-hr monitoring period. A repeated measures study design was used where resting ECGs and blood samples were taken from individuals before SHS exposure (baseline), immediately following SHS exposure (post) and the morning following SHS exposure (next-morning). Inflammatory markers, including high sensitivity C-reactive protein (CRP) and white blood cell count (WBC) were analyzed. Heart rate variability (HRV) was analyzed from the ECG recordings in time (SDNN, rMSSD) and frequency (LF, HF) domain parameters over 5-minute periods. SHS exposure was quantified using a personal fine particulate matter (PM2.5) monitor. Linear mixed effects regression models were used to examine within-person changes in inflammatory and HRV parameters across the 3 time periods. Exposure-response relationships with PM2.5 were examined using mixed effects models. All models were adjusted for age, BMI and circadian variation. Results: A total of 32 male non-smokers were monitored between June 2010 and June 2012. The mean PM2.5 from SHS exposure was 132 μg/m3. Immediately following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with declines in HRV (7.8% [standard error (SE) =3%] SDNN, 8.0% (SE = 3.9%) rMSSD, 17.2% (SE = 6.3%) LF, 29.0% (SE = 10.1%) HF) and increases in WBC count 0.42 (SE = 0.14) k/μl. Eighteen hours following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with 24.2% higher CRP levels. Conclusions: Our study suggest that short-term SHS exposure is associated with significantly lower HRV and higher levels of inflammatory markers. Exposure-associated declines in HRV were observed immediately following exposure while higher levels of CRP were not observed until 18 hours following exposure. Cardiovascular autonomic and inflammation responses may contribute to the pathophysiologic pathways that link SHS exposure with adverse cardiovascular outcomes.
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    Heart rate variability and DNA methylation levels are altered after short-term metal fume exposure among occupational welders: a repeated-measures panel study
    (BioMed Central, 2014) Fan, Tianteng; Fang, Shona C; Cavallari, Jennifer M; Barnett, Ian; Wang, Zhaoxi; Su, Li; Byun, Hyang-Min; Lin, Xihong; Baccarelli, Andrea; Christiani, David
    Background: In occupational settings, boilermakers are exposed to high levels of metallic fine particulate matter (PM2.5) generated during the welding process. The effect of welding PM2.5 on heart rate variability (HRV) has been described, but the relationship between PM2.5, DNA methylation, and HRV is not known. Methods: In this repeated-measures panel study, we recorded resting HRV and measured DNA methylation levels in transposable elements Alu and long interspersed nuclear element-1 (LINE-1) in peripheral blood leukocytes under ambient conditions (pre-shift) and right after a welding task (post-shift) among 66 welders. We also monitored personal PM2.5 level in the ambient environment and during the welding procedure. Results: The concentration of welding PM2.5 was significantly higher than background levels in the union hall (0.43 mg/m3 vs. 0.11 mg/m3, p < 0.0001). The natural log of transformed power in the high frequency range (ln HF) had a significantly negative association with PM2.5 exposure (β = -0.76, p = 0.035). pNN10 and pNN20 also had a negative association with PM2.5 exposure (β = -0.16%, p = 0.006 and β = -0.13%, p = 0.030, respectively). PM2.5 was positively associated with LINE-1 methylation [β = 0.79%, 5-methylcytosince (%mC), p = 0.013]; adjusted for covariates. LINE-1 methylation did not show an independent association with HRV. Conclusions: Acute decline of HRV was observed following exposure to welding PM2.5 and evidence for an epigenetic response of transposable elements to short-term exposure to high-level metal-rich particulates was reported. Electronic supplementary material The online version of this article (doi:10.1186/1471-2458-14-1279) contains supplementary material, which is available to authorized users.
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    Short-term metal particulate exposures decrease cardiac acceleration and deceleration capacities in welders: a repeated-measures panel study
    (BMJ Publishing Group, 2016) Umukoro, Peter E; Cavallari, Jennifer M; Fang, Shona C; Lu, Chensheng; Lin, Xihong; Mittleman, Murray; Christiani, David
    Objective: Acceleration (AC) and deceleration (DC) capacities measure heart rate variability during speeding up and slowing down of the heart, respectively. We investigated associations between AC and DC with occupational short-term metal PM2.5 exposures. Methods: A panel of 48 male welders had particulate matter less than 2.5 microns in diameter (PM2.5) exposure measurements over 4–6 h repeated over 5 sampling periods between January 2010 and June 2012. We simultaneously obtained continuous recordings of digital ECG using a Holter monitor. We analysed ECG data in the time domain to obtain hourly AC and DC. Linear mixed models were used to assess the associations between hourly PM2.5 exposure and each of hourly AC and DC, controlling for age, smoking status, active smoking, exposure to secondhand smoke, season/time of day when ECG reading was obtained and baseline AC or DC. We also ran lagged exposure response models for each successive hour up to 3 h after onset of exposure. Results: Mean (SD) shift PM2.5 exposure during welding was 0.47 (0.43) mg/m3. Significant exposure–response associations were found for AC and DC with increased PM2.5 exposure. In our adjusted models without any lag between exposure and response, a 1 mg/m3 increase of PM2.5 was associated with a decrease of 1.46 (95% CI 1.00 to 1.92) ms in AC and a decrease of 1.00 (95% CI 0.53 to 1.46) ms in DC. The effect of PM2.5 on AC and DC was maximal immediately postexposure and lasted 1 h following exposure. Conclusions: There are short-term effects of metal particulates on AC and DC.
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    Assessment of Residents’ Attitudes and Satisfaction Before and After Implementation of a Smoke-Free Policy in Boston Multiunit Housing
    (Oxford University Press (OUP), 2015) Rokicki, Slawa; Adamkiewicz, Gary; Fang, Shona C; Rigotti, Nancy; Winickoff, Jonathan; Levy, Douglas
    Introduction: In 2012, the Boston Housing Authority (BHA) in Massachusetts implemented a smoke-free policy prohibiting smoking within its residences. We sought to characterize BHA resident experiences before and after the smoke-free policy implementation, and compare them to that of nearby residents of the Cambridge Housing Authority, which had no such policy. Methods: We recruited a convenience sample of nonsmoking residents from the BHA and Cambridge Housing Authority. We measured residents’ awareness and support of their local smoking policies before and 9–12 months after the BHA’s policy implementation, as well as BHA respondents’ attitudes towards the smoke-free policy. We assessed tobacco smoke exposure via saliva cotinine, airborne apartment nicotine, and self-reported number of days smelling smoke in the home. We evaluated predictors of general satisfaction at follow-up using linear regression. Results: At follow-up, 91% of BHA respondents knew that smoking was not allowed in apartments and 82% were supportive of such a policy in their building. BHA residents believed enforcement of the smoke-free policy was low. Fifty-one percent of BHA respondents indicated that other residents “never” or “rarely” followed the new smoke-free rule and 41% of respondents were dissatisfied with policy enforcement. Dissatisfaction with enforcement was the strongest predictor of general housing satisfaction, while objective and self-reported measures of tobacco smoke exposure were not predictive of satisfaction. At follow-up, 24% of BHA participants had complained to someone in charge about policy violations. Conclusions: Resident support for smoke-free policies is high. However, lack of enforcement of smoke-free policies may cause frustration and resentment among residents, potentially leading to a decrease in housing satisfaction. Implications: Smoke-free housing laws are becoming increasingly prevalent, yet little is known about satisfaction and compliance with such policies post-implementation. We evaluated nonsmoking residents’ attitudes about smoke-free rules and their satisfaction with enforcement 1 year after the BHA implemented its comprehensive smoke-free policy. We found that while residents were supportive of the policy, they believed enforcement was low, a perception that was associated with a drop in housing satisfaction. Our findings point to a desire for smoke-free housing among public housing residents, and the importance of establishing systems and guidelines to help landlords monitor and enforce these policies effectively.
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    Biogeographic Ancestry Is Associated with Higher Total Body Adiposity among African-American Females: The Boston Area Community Health Survey
    (Public Library of Science, 2015) Goonesekera, Sunali D.; Fang, Shona C; Piccolo, Rebecca S.; Florez, Jose; McKinlay, John B.
    Objectives: The prevalence of obesity is disproportionately higher among African-Americans and Hispanics as compared to whites. We investigated the role of biogeographic ancestry (BGA) on adiposity and changes in adiposity in the Boston Area Community Health Survey. Methods: We evaluated associations between BGA, assessed via Ancestry Informative Markers, and adiposity (body mass index (BMI), percent body fat (PBF), and waist-to-hip ratio (WHR)) and changes in adiposity over 7 years for BMI and WHR and 2.5 years for PBF, per 10% greater proportion of BGA using multivariable linear regression. We also examined effect-modification by demographic and socio-behavioral variables. Results: We observed positive associations between West-African ancestry and cross-sectional BMI (percent difference=0.62%; 95% CI: 0.04%, 1.20%), and PBF (β=0.35; 95% CI: 0.11, 0.58). We also observed significant effect-modification of the association between West-African ancestry and BMI by gender (p-interaction: <0.002) with a substantially greater association in women. We observed no main associations between Native-American ancestry and adiposity but observed significant effect-modification of the association with BMI by diet (p-interaction: <0.003) with inverse associations among participants with higher Healthy Eating Scores. No associations were observed between BGA and changes in adiposity over time. Conclusion: Findings support that West-African ancestry may contribute to high prevalence of total body adiposity among African-Americans, particularly African-American women.
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    Lead Concentrations in Relation to Multiple Biomarkers of Cardiovascular Disease: The Normative Aging Study
    (National Institute of Environmental Health Sciences, 2012) Peters, Junenette L.; Kubzansky, Laura; Ikeda, Ai; Fang, Shona C; Sparrow, David; Weisskopf, Marc; Wright, Robert; Vokonas, Pantel; Hu, Howard; Schwartz, Joel
    Background: Lead exposure has been associated with cardiovascular disease (CVD) in animal and human studies. However, the mechanisms of action have not been fully elucidated. We therefore examined the relationship between lead and multiple biomarkers of CVD. Methods: Participants were older men from the Normative Aging Study without preexisting coronary heart disease, diabetes, or active infection at baseline (n = 426). Serum biomarkers included lipid profile [total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides] and inflammatory markers [C-reactive protein, intercellular adhesion molecule-1, interleukin-6, and tumor necrosis factor receptor-2 (TNF-R2)]. We measured lead in blood and in bone by K-shell X-ray fluorescence. In this sample, 194 men (44.3%) had two or more repeated measures, resulting in 636 observations for analysis. We conducted analyses using mixed effects models with random subject intercepts. Results: Lead levels were associated with several CVD biomarkers, including levels of TNF-R2 and lipid markers. Specifically, in multivariable models, a 50% increase in blood lead level was associated with 26% increased odds of high TNF-R2 levels (> 5.52 ng/mL; odds ratio = 1.26; 95% confidence interval: 1.09, 1.45). There were positive associations of blood lead level with total cholesterol and HDL levels, and these associations were more evident when modeled as continuous outcomes than when categorized using clinically relevant cut points. In addition, longitudinal analyses indicated a significant increase in TNF-R2 levels over time to be associated with high blood lead level at the preceding visit. Conclusions: Blood lead level may be related with CVD in healthy older men through its association with TNF-R2 levels. In addition, the magnitude of the association of blood lead level with TNF-R2 level increased with age in the study population.
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    Residential Black Carbon Exposure and Circulating Markers of Systemic Inflammation in Elderly Males: The Normative Aging Study
    (National Institute of Environmental Health Sciences, 2012) Fang, Shona C; Mehta, A; Alexeeff, Stacey E.; Gryparis, Alexandros; Coull, Brent; Vokonas, Pantel; Christiani, David; Schwartz, Joel
    Background: Traffic-related particles (TRPs) are associated with adverse cardiovascular events. The exact mechanisms are unclear, but systemic inflammatory responses likely play a role. Objectives: We conducted a repeated measures study among male participants of the Normative Aging Study in the greater Boston, Massachusetts, area to determine whether individual-level residential black carbon (BC), a marker of TRPs, is associated with systemic inflammation and whether coronary heart disease (CHD), diabetes, and obesity modify associations. Methods: We quantified markers of inflammation in 1,163 serum samples from 580 men. Exposure to BC up to 4 weeks prior was predicted from a validated spatiotemporal land-use regression model. Linear mixed effects models estimated the effects of BC on each marker while adjusting for potential confounders. Results: Associations between BC and blood markers were not observed in main effects models or when stratified by obesity status. However, BC was positively associated with markers of inflammation in men with CHD (particularly vascular endothelial growth factor) and in men with diabetes (particularly interleukin-1\(\beta\) and tumor necrosis factor-\(\alpha\)). Significant exposure time windows varied by marker, although in general the strongest associations were observed with moving averages of 2–7 days after a lag of several days. Conclusions: In an elderly male population, estimated BC exposures were positively associated with markers of systemic inflammation but only in men with CHD or diabetes.