1. Association between emergency admission for peptic ulcer bleeding and air pollution: a case-crossover analysis in Hong Kong's elderly population 
Linwei Tian, PhD, Hong Qiu, PhD, Shengzhi Sun, MPhil, Hilda Tsang, MPhil, King-Pan Chan, MPhil, Prof Wai K Leung, MD 
The Lancet Planetary Health 
Volume 1, Issue 2, Pages e74-e81 (May 2017)
DOI: /S (17)
Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions

2. Figure 1
Map of Hong Kong showing the location of the general or background air pollution monitoring stations and Hong Kong Observatory
NO2, SO2, and O3 concentrations were averaged from ten stations except TM, whereas PM2·5 concentrations were computed from three stations (TW, YL, and TC) during the study period of 2005–10. PM2·5=particulate matter with aerodynamic diameter less than 2·5 μm. NO2=nitrogen dioxide. SO2=sulfur dioxide. O2=ozone.
The Lancet Planetary Health 2017 1, e74-e81DOI: ( /S (17) )
Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions

3. Figure 2
Time series plot of the daily mean air pollution concentrations and emergency hospital admissions for peptic ulcer bleeding in the elderly population in Hong Kong, 2005–10
PM2·5=particulate matter with aerodynamic diameter less than 2·5 μm. NO2=nitrogen dioxide. SO2=sulfur dioxide. O3=ozone.
The Lancet Planetary Health 2017 1, e74-e81DOI: ( /S (17) )
Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions

4. Figure 3
Exposure-response relationship curves for the association between emergency hospital admissions for peptic ulcer bleeding and 5-day moving average (lag04) of NO2 concentrations in single-pollutant and multi-pollutant models, respectively
The Lancet Planetary Health 2017 1, e74-e81DOI: ( /S (17) )
Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions