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 140 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. He is currently leading two multidisciplinary, multi-institutional centers studying the health impact of engineered nanomaterials.

Positions:

Professor of Global and Environmental Health

Environmental Sciences and Policy
Nicholas School of the Environment

Professor at Duke Kunshan University

DKU Faculty
Duke Kunshan University

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:

Duke University Program in Environmental Health

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

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
Role
Co-Mentor
Start Date
End Date

Publications:

Diurnal variations of greenhouse gases emissions from reclamation mariculture ponds

© 2020 Dissolved concentrations, saturation status, and emission fluxes of greenhouse gases (GHGs) in two reclamation mariculture ponds in the Bohai Gulf, China, were measured using the static headspace gas chromatography method and computed using a two-layer model of diffusive gas exchange. The study was conducted during August 2016 to assess diurnal variations in GHGs emissions. The main influencing factors of GHGs emissions from the ponds under the disturbance of artificial management were identified using Spearman correlation analyses and multiple stepwise regression analyses. Results showed that dissolved GHGs concentrations were stable throughout the day, whereas GHGs emission fluxes showed a clear diurnal variation with larger daytime values. The diurnal variation of N2O emission fluxes was greater than that of CO2 and that of CH4. Results also showed that pH of pond water was negatively correlated with CO2 and N2O emission fluxes and that air temperature was positively correlated with CH4 and N2O emission fluxes. In addition, ammonia (NH4+-N) was positively correlated with CH4 emission fluxes; water temperature and salinity were positively correlated with N2O emission fluxes. The estimated annual emissions from the reclamation aquaculture in Tianjin and the Bohai Rim region were 2.53 × 105 kg C–CO2, 6.94 × 103 kg C–CH4 and 1.11 × 103 kg N–N2O, and 3.42 × 107 kg C–CO2, 9.36 × 105 kg C–CH4 and 1.50 × 105 kg N–N2O respectively, indicating the important contribution of this fishery sector to GHGs emissions.
Authors
Hu, B; Xu, X; Zhang, J; Wang, T; Meng, W; Wang, D
MLA Citation
Hu, B., et al. “Diurnal variations of greenhouse gases emissions from reclamation mariculture ponds.” Estuarine, Coastal and Shelf Science, vol. 237, May 2020. Scopus, doi:10.1016/j.ecss.2020.106677.
URI
https://scholars.duke.edu/individual/pub1434343
Source
scopus
Published In
Estuarine, Coastal and Shelf Science
Volume
237
Published Date
DOI
10.1016/j.ecss.2020.106677

Season and size of urban particulate matter differentially affect cytotoxicity and human immune responses to Mycobacterium tuberculosis.

Exposure to air pollution particulate matter (PM) and tuberculosis (TB) are two of the leading global public health challenges affecting low and middle income countries. An estimated 4.26 million premature deaths are attributable to household air pollution and an additional 4.1 million to outdoor air pollution annually. Mycobacterium tuberculosis (M.tb) infects a large proportion of the world's population with the risk for TB development increasing during immunosuppressing conditions. There is strong evidence that such immunosuppressive conditions develop during household air pollution exposure, which increases rates of TB development. Exposure to urban air pollution has been shown to alter the outcome of TB therapy. Here we examined whether in vitro exposure to urban air pollution PM alters human immune responses to M.tb. PM2.5 and PM10 (aerodynamic diameters <2.5μm, <10μm) were collected monthly from rainy, cold-dry and warm-dry seasons in Iztapalapa, a highly populated TB-endemic municipality of Mexico City with elevated outdoor air pollution levels. We evaluated the effects of seasonality and size of PM on cytotoxicity and antimycobacterial host immunity in human peripheral blood mononuclear cells (PBMC) from interferon gamma (IFN-γ) release assay (IGRA)+ and IGRA- healthy study subjects. PM10 from cold-dry and warm-dry seasons induced the highest cytotoxicity in PBMC. With the exception of PM2.5 from the cold-dry season, pre-exposure to all seasonal PM reduced M.tb phagocytosis by PBMC. Furthermore, M.tb-induced IFN-γ production was suppressed in PM2.5 and PM10-pre-exposed PBMC from IGRA+ subjects. This observation coincides with the reduced expression of M.tb-induced T-bet, a transcription factor regulating IFN-γ expression in T cells. Pre-exposure to PM10 compared to PM2.5 led to greater loss of M.tb growth control. Exposure to PM2.5 and PM10 collected in different seasons differentially impairs M.tb-induced human host immunity, suggesting biological mechanisms underlying altered M.tb infection and TB treatment outcomes during air pollution exposures.
Authors
Sarkar, S; Rivas-Santiago, CE; Ibironke, OA; Carranza, C; Meng, Q; Osornio-Vargas, Á; Zhang, J; Torres, M; Chow, JC; Watson, JG; Ohman-Strickland, P; Schwander, S
MLA Citation
Sarkar, Srijata, et al. “Season and size of urban particulate matter differentially affect cytotoxicity and human immune responses to Mycobacterium tuberculosis.Plos One, vol. 14, no. 7, Jan. 2019, p. e0219122. Epmc, doi:10.1371/journal.pone.0219122.
URI
https://scholars.duke.edu/individual/pub1397652
PMID
31295271
Source
epmc
Published In
Plos One
Volume
14
Published Date
Start Page
e0219122
DOI
10.1371/journal.pone.0219122

Relationship between free and total malondialdehyde, a well-established marker of oxidative stress, in various types of human biospecimens.

Background:Oxidative stress is involved in thoracic diseases and health responses to air pollution. Malondialdehyde (MDA) is a well-established marker of oxidative stress, but it may be present in unconjugated and conjugated forms. To our knowledge, no studies have conducted a systemic evaluation of both free MDA (unconjugated MDA) and total MDA (the sum of both unconjugated and conjugated MDA) across various types of human biospecimens. Methods:Free MDA and total MDA were simultaneously measured in a range of human biospecimens, including nasal fluid (N=158), saliva (N=158), exhaled breath condensate (N=40), serum (N=232), and urine (N=429). All samples were analyzed using an HPLC-fluorescence method with high sensitivity and specificity. Due to the right skewed distribution of free MDA and total MDA, we performed natural-log transformation before subsequent statistical analyses. The relationship between the natural log of free and total MDA was evaluated by R2 of simple linear regression. T test was used for comparisons of means between two groups. One-way analysis of variance was used in combination with Tukey's test to compare the natural log of the ratio of free MDA to total MDA across various types of biospecimens. Results:For exhaled breath condensate, serum, urine, nasal fluid and saliva samples, the R2 between free and total MDA were 0.61, 0.22, 0.59, 0.47 and 0.06, respectively; the medians of the free MDA to total MDA ratio were 48.1%, 17.4%, 9.8%, 5.1% and 3.0%, respectively; the free MDA to total MDA ratio in EBC > serum > urine > nasal fluid > saliva (P<0.001 for pairwise comparisons). Conclusions:For exhaled breath condensate and urine samples, using either free or total MDA can provide information regarding the level of oxidative stress; however, that is not the case for serum, nasal fluid, and saliva given the low correlations between free and total MDA.
Authors
Cui, X; Gong, J; Han, H; He, L; Teng, Y; Tetley, T; Sinharay, R; Chung, KF; Islam, T; Gilliland, F; Grady, S; Garshick, E; Li, Z; Zhang, JJ
MLA Citation
Cui, Xiaoxing, et al. “Relationship between free and total malondialdehyde, a well-established marker of oxidative stress, in various types of human biospecimens.Journal of Thoracic Disease, vol. 10, no. 5, May 2018, pp. 3088–97. Epmc, doi:10.21037/jtd.2018.05.92.
URI
https://scholars.duke.edu/individual/pub1322969
PMID
29997978
Source
epmc
Published In
Journal of Thoracic Disease
Volume
10
Published Date
Start Page
3088
End Page
3097
DOI
10.21037/jtd.2018.05.92

Associations of personal exposure to air pollutants with airway mechanics in children with asthma.

BACKGROUND:The importance of airway mechanics has been increasingly recognized in pediatric asthma. However, no studies have examined responses of airway mechanics to air pollution exposure in asthmatic children. METHODS:In this panel study involving indoor air filtration manipulation that created a large gradient of personal exposure to PM2.5, the airway mechanics and lung function of 43 asthmatic children 5-13 years old in a suburb of Shanghai were measured four times within 3 consecutive months. Concentrations of indoor and outdoor PM2.5 and ozone were coupled with individual time-activity data to calculate personal exposures. Linear mixed effects models were used to examine the relationships of personal exposure with indicators of airway mechanics and lung function, respectively. RESULTS:An interquartile range (IQR) increase in 24-hour average PM2.5 personal exposure (30.3 µg/m3) in the prior day was associated with significant increases in small airway resistance (R5-R20) of 15.8%, total airway resistance (R5) of 6.3%, and airway inflammation (FeNO) of 9.6%. These associations were stronger in children with lower blood eosinophil counts (<450/µL). No significant associations were found between personal PM2.5 exposure and lung function. Low-level ozone exposure (daily maximum 8-hour exposure range 1.1-56.4 ppb) was not significantly associated with any of the outcomes. CONCLUSION:Changes in personal PM2.5 exposure, partly enhanced by air filtration, were associated with significant changes in airway resistance and inflammation in children with asthma. These findings suggest the importance of reducing PM2.5 exposure, via personal air quality management, in improving airflow limitation in the airways, especially the small airways.
Authors
He, L; Li, Z; Teng, Y; Cui, X; Barkjohn, KK; Norris, C; Fang, L; Lin, L; Wang, Q; Zhou, X; Hong, J; Li, F; Zhang, Y; Schauer, JJ; Black, M; Bergin, MH; Zhang, JJ
MLA Citation
He, Linchen, et al. “Associations of personal exposure to air pollutants with airway mechanics in children with asthma.Environment International, vol. 138, May 2020, p. 105647. Epmc, doi:10.1016/j.envint.2020.105647.
URI
https://scholars.duke.edu/individual/pub1434780
PMID
32172043
Source
epmc
Published In
Environment International
Volume
138
Published Date
Start Page
105647
DOI
10.1016/j.envint.2020.105647

Ozone in urban China: Impact on mortalities and approaches for establishing indoor guideline concentrations.

Reducing indoor ozone levels may be an effective strategy to reduce total exposure and associated mortality. Here we estimate (a) premature mortalities attributable to ozone for China's urban population ≥25 years of age; (b) the fraction of total exposure occurring indoors; and (c) mortalities that can be potentially avoided through meeting current and more stringent indoor ozone standards/guidelines based on 1-hour daily maxima. To estimate ozone-attributable premature mortalities, we used hourly outdoor ozone concentrations measured at 1497 monitoring stations located in 339 Chinese cities and a published concentration-response model. We proceeded to estimate province-specific infiltration factors and co-occurring hourly indoor ozone concentrations. For the year 2015, we estimated that indoor exposures accounted for 59% (95% confidence interval (CI): 26%-79%) of the total ozone exposure that resulted in 70800 (95% CI: 35 900-137 700) premature all-cause mortalities in urban China. If the current Chinese indoor ozone standards (80 ppbv (160 µg/m3 ); 56 ppbv (112 µg/m3 )) were met, the mean estimates of reduction in mortalities would be indistinguishable from zero. With stricter 1-hour indoor ozone guidelines, the expected mortality reductions increase exponentially per unit decrease in indoor ozone. The analysis in this paper should help facilitate formulating present and future indoor ozone guidelines.
Authors
Xiang, J; Weschler, CJ; Zhang, J; Zhang, L; Sun, Z; Duan, X; Zhang, Y
MLA Citation
Xiang, Jianbang, et al. “Ozone in urban China: Impact on mortalities and approaches for establishing indoor guideline concentrations.Indoor Air, vol. 29, no. 4, July 2019, pp. 604–15. Epmc, doi:10.1111/ina.12565.
URI
https://scholars.duke.edu/individual/pub1383522
PMID
31077433
Source
epmc
Published In
Indoor Air
Volume
29
Published Date
Start Page
604
End Page
615
DOI
10.1111/ina.12565