Junfeng Zhang

Overview:

Dr. Zhang joined the Duke Faculty in fall 2013 from the University of Southern California where he had been a professor of environmental and global health and the director of Environmental and Biomarkers Analysis Laboratory since 2010. His prior positions include professor, department chair, and associate dean at the Rutgers School of Public Health. Dr. Zhang has more than 290 peer-reviewed publications. His work has been featured in major international media such as the Time, the New York Times, BBC, ABC, CBS, Yahoo News, etc. His early work on characterizing sources of non-methane greenhouse gases made him one of the officially recognized contributor to the 2007 Nobel Peace Prize awarded to IPCC. He is the 2012 recipient of the Jeremy Wesolowski Award, the highest award of the International Society of Exposure Science. He also received a Distinguished Alumni Award from the Rutgers Graduate School.

Dr. Zhang’s research interests include developing novel biomarkers of human exposure and health effects, assessing health and climate co-benefits of air pollution interventions, and examining biological mechanisms by which environmental exposures exert adverse health effects. Dr. Zhang has led a number of international collaborations to study air pollution health effects and underlying pathophysiologic mechanisms. These studies integrate epidemiological and toxicological approaches into natural experiment designs. He has conducted several indoor air purification intervention studies to evaluate the effectiveness of personal exposure reduction in improving health outcomes in China. Currently, he is conducting intervention trials of residential air purification in older adults with a heart disease history and adults at risk for Type 2 diabetes living in Los Angels where air pollution levels are high. He is co-leading a project to study whether and how particulate matter pollution affects respiratory viral infections in two cities of Mongolia. 

Positions:

Professor of Global and Environmental Health

Environmental Sciences and Policy
Nicholas School of the Environment

Chair of the Environmental Sciences and Policy Division

Environmental Sciences and Policy
Nicholas School of the Environment

Research Professor of Global Health

Duke Global Health Institute
Institutes and Provost's Academic Units

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 1994

Rutgers University

Grants:

Cooperative Program in Nanomaterials Hazard and Exposure Assessment Traineeships (NanoHEAT)

Administered By
Pratt School of Engineering
Awarded By
Environmental Protection Agency
Role
Mentor
Start Date
End Date

Duke University Program in Environmental Health

Administered By
Environmental Sciences and Policy
Awarded By
National Institute of Environmental Health Sciences
Role
Mentor
Start Date
End Date

Effects of perfluorobutane sulfonate (PFBS) exposure on adverse pregnancy outcomes and fetal development

Administered By
Obstetrics and Gynecology, Reproductive Sciences
Awarded By
National Institutes of Health
Role
Mentor
Start Date
End Date

The effect of household air pollution on the health outcomes of infants in Botswana

Administered By
Medicine, Pulmonary, Allergy, and Critical Care Medicine
Awarded By
Thrasher Research Fund
Role
Co-Mentor
Start Date
End Date

Measurement of urinary 8-isoprostane and 11-dehydrothromboxane

Administered By
Duke Global Health Institute
Awarded By
University of California - San Francisco
Role
Principal Investigator
Start Date
End Date

Publications:

Benefits from disease-burden reduction for type 2 diabetes and obesity through comprehensive regulatory restrictions on phthalate use in China

Evidence is accumulating that the increasing incidence of type 2 diabetes and obesity is correlated with exposure to certain phthalates, which brings growing concern to the public health of China. However, the extent to which phthalate restrictions will alleviate these health concerns remains unclear. Here, we employed a sequential modeling approach to evaluate the impact that a series of restrictions would have on the mass of phthalates in the use phase, indoor concentrations, exposure, and the attributable disease burden of type 2 diabetes and obesity in adults. We show that, compared with the business-as-usual scenario, the implementation of the strongest restriction on the concerned phthalates in 2016 can decrease the use of phthalates by up to 91.2%, indoor airborne phthalate concentrations by 93.8%, and indoor dust-phase phthalate concentrations by 90.2% by 2031. Correspondingly, the decrease in phthalate exposure would result in a health benefit of 134.6 billion CNY. These findings call for the urgent need to restrict the use of certain phthalates to reduce the burden of type 2 diabetes and obesity in China.
Authors
Shi, S; Zhang, J; Gong, J; Zhao, B
MLA Citation
Shi, S., et al. “Benefits from disease-burden reduction for type 2 diabetes and obesity through comprehensive regulatory restrictions on phthalate use in China.” One Earth, vol. 5, no. 4, Apr. 2022, pp. 380–91. Scopus, doi:10.1016/j.oneear.2022.03.013.
URI
https://scholars.duke.edu/individual/pub1519664
Source
scopus
Published In
One Earth
Volume
5
Published Date
Start Page
380
End Page
391
DOI
10.1016/j.oneear.2022.03.013

Boiler briquette coal versus raw coal: Part I--Stack gas emissions.

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BB-coal were 2.51 for PM10, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/steam conversion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for CO, while those of the BB-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also presented for both types of coal tested in the study.
Authors
Ge, S; Bai, Z; Liu, W; Zhu, T; Wang, T; Qing, S; Zhang, J
MLA Citation
Ge, S., et al. “Boiler briquette coal versus raw coal: Part I--Stack gas emissions.Journal of the Air & Waste Management Association (1995), vol. 51, no. 4, Apr. 2001, pp. 524–33. Epmc, doi:10.1080/10473289.2001.10464293.
URI
https://scholars.duke.edu/individual/pub1526157
PMID
11321909
Source
epmc
Published In
Journal of the Air & Waste Management Association (1995)
Volume
51
Published Date
Start Page
524
End Page
533
DOI
10.1080/10473289.2001.10464293

Field Evaluation of a Potential Exposure Biomarker of Methylated Polycyclic Aromatic Hydrocarbons: Association between Urinary Phenanthrene-2-carboxylic Acid and Personal Exposure to 2-Methylphenanthrene

Previous in vitro studies identified carboxylic acids as the major metabolites of methylated polycyclic aromatic hydrocarbons (PAHs). We have previously detected phenanthrene-2-carboxylic acid (2-PHECA) in human urine, but a direct linkage between this biomarker and external exposure to methylated PAHs remains unestablished. Herein, we analyzed phenanthrene (PHE) and 2-MePHE in 589 personal PM2.5 samples and hydroxy-phenanthrenes (ςOH-PHEs) and 2-PHECA in paired urine samples from 120 urban residents. We observed higher personal 2-MePHE and PHE exposure but lower urinary 2-PHECA and ςOH-PHEs levels in the heating season, possibly due to changes in gas-particle partitioning, dietary source, and metabolism. After adjusting for seasonal effects, urinary 2-PHECA concentrations were significantly associated with personal exposure to 2-MePHE but not PHE. We also found significant associations between the urinary 2-PHECA/ςOH-PHEs ratio and personal 2-MePHE/PHE ratio, an indicator for the petrogenic versus pyrogenic sources. Alcohol consumption was identified as an influencing factor for the 2-PHECA level and 2-PHECA/ςOH-PHEs ratio, likely via competing the metabolism of 2-MePHE by alcohol and aldehyde dehydrogenases. These results suggest the potential usefulness of the urinary 2-PHECA level as a biomarker of methylated PAH exposure and the 2-PHECA/ςOH-PHEs ratio as a biomarker for the relative importance of petrogenic or pyrogenic sources.
Authors
Lin, Y; Zhang, H; Han, Y; Qiu, X; Jiang, X; Cheng, Z; Wang, Y; Chen, X; Fan, Y; Li, W; Zhang, J; Zhu, T
MLA Citation
Lin, Y., et al. “Field Evaluation of a Potential Exposure Biomarker of Methylated Polycyclic Aromatic Hydrocarbons: Association between Urinary Phenanthrene-2-carboxylic Acid and Personal Exposure to 2-Methylphenanthrene.” Environmental Science and Technology Letters, vol. 9, no. 2, Feb. 2022, pp. 166–72. Scopus, doi:10.1021/acs.estlett.1c00938.
URI
https://scholars.duke.edu/individual/pub1506668
Source
scopus
Published In
Environmental Science & Technology Letters
Volume
9
Published Date
Start Page
166
End Page
172
DOI
10.1021/acs.estlett.1c00938

The effect of China's Clean Air Act on cognitive function in older adults: a population-based, quasi-experimental study.

<h4>Background</h4>Air pollution might accelerate cognitive ageing; it is unclear whether large-scale interventions, such as China's Clean Air Act (CCAA), can mitigate cognitive deterioration. We aimed to evaluate the effect of CCAA on changes in cognitive function in older adults.<h4>Methods</h4>In this population-based, quasi-experimental study, we did a difference-in-differences analysis of the data collected during the 2014 and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The study design used a counterfactual analysis feature by dividing CLHLS participants into two groups. The intervention group included participants who lived in areas where the provincial government set a target of reducing particulate matter (PM) by at least 5% annually from 2014 onward, whereas the control group consisted of individuals who lived in areas without a PM reduction target. Global cognitive function was measured using the Mini-Mental State Examination (MMSE). We used fixed-effects models to examine the between-group differences in MMSE score changes before and after CCAA implementation. We associated longitudinal changes in MMSE scores with changes in concentrations of PM with a diameter of less than 2·5 μm (PM<sub>2·5</sub>) concentration and other regulated pollutants. We used alternative models and sensitivity analyses to evaluate the robustness of the results from the main models.<h4>Findings</h4>2812 individuals participated in the 2014 and 2018 surveys (mean age 81·0 years [SD 9·3] in 2014; 1408 [50·1%] female and 1404 [49·9%] male). 2251 (80·0%) were included in the intervention group and 561 (20·0%) in the control group. After controlling for potential confounders, the intervention group had a significantly smaller decline in MMSE scores from 2014 to 2018 compared with the control group: the mean between-group difference was 2·45 points (95% CI 1·32-3·57). Interquartile increases in PM<sub>2·5</sub> were associated with a significant MMSE score decline of 0·83 points (95% CI 0·24-1·42); similarly, increases in SO<sub>2</sub> were also associated with a significant MMSE score decline of 0·80 points (0·32-1·29).<h4>Interpretation</h4>Implementing stringent clean air policies might mitigate the risk of air pollutant-associated cognitive ageing in older people.<h4>Funding</h4>National Natural Sciences Foundation of China, National Key R&D Program of China, China Postdoctoral Science Foundation funded project, the Duke/Duke-National University of Singapore Collaboration Pilot Project, the National Institute on Aging and Peking University-Baidu Fund, Energy Foundation, and the Fundamental Research Funds for the Central Universities.
Authors
Yao, Y; Lv, X; Qiu, C; Li, J; Wu, X; Zhang, H; Yue, D; Liu, K; Eshak, ES; Lorenz, T; Anstey, KJ; Livingston, G; Xue, T; Zhang, J; Wang, H; Zeng, Y
MLA Citation
Yao, Yao, et al. “The effect of China's Clean Air Act on cognitive function in older adults: a population-based, quasi-experimental study.The Lancet. Healthy Longevity, vol. 3, no. 2, Feb. 2022, pp. e98–108. Epmc, doi:10.1016/s2666-7568(22)00004-6.
URI
https://scholars.duke.edu/individual/pub1509364
PMID
35224526
Source
epmc
Published In
The Lancet Healthy Longevity
Volume
3
Published Date
Start Page
e98
End Page
e108
DOI
10.1016/s2666-7568(22)00004-6

Particulate matter (PM) oxidative potential: Measurement methods and links to PM physicochemical characteristics and health effects

It has been widely accepted that the induction of reactive oxygen species (ROS) is an important pathophysiologic pathway linking particulate matter (PM) exposure and adverse health effects. ROS can be either present on and/or within PM or generated in vivo by the interactions between PM and biological systems. Within the context of toxicology, PM oxidative potential (OP) is the capacity of PM to oxidize molecules in biological tissues or cells directly by oxidants that are present on and/or within PM and indirectly by the ROS generated via PM interactions with the biological system (e.g., fluids, cells, and tissues). In this review, we summarized the current PM OP measurement methods, current understanding of how PM physical characteristics and chemical compositions affect OP, and the epidemiological and toxicological evidence on whether PM OP is a better indicator than PM mass concentration for health effects. Among the two major types of OP measurement methods, cellular assays have been regarded to better reflect the actions of PM in a biological system than acellular assays. Recent epidemiological studies have associated short-term PM OP exposure with adverse cardiorespiratory health outcomes. Little is known about the health effects of long-term PM OP exposure and on the effect beyond the cardiovascular and respiratory systems. The existing evidence may be sufficient to suggest the use of PM OP as a more health-relevant exposure metric than conventional PM mass concentration, but critical methodologic issues must be resolved before this metric can be widely and accurately used.
Authors
He, L; Zhang, J
MLA Citation
He, L., and J. Zhang. “Particulate matter (PM) oxidative potential: Measurement methods and links to PM physicochemical characteristics and health effects.” Critical Reviews in Environmental Science and Technology, Jan. 2022. Scopus, doi:10.1080/10643389.2022.2050148.
URI
https://scholars.duke.edu/individual/pub1513707
Source
scopus
Published In
Critical Reviews in Environmental Science and Technology
Published Date
DOI
10.1080/10643389.2022.2050148