Effect Modifications of Overhead-View and Eye-Level Urban Greenery on Heat–Mortality Associations: Small-Area Analyses Using Case Time Series Design and Different Greenery Measurements

Background: The protective effect of urban greenery from adverse heat impacts remains inconclusive. Existing inconsistent findings could be attributed to the different estimation techniques used. Objectives: We investigated how effect modifications of urban greenery on heat–mortality associations vary when using different greenery measurements reflecting overhead-view and eye-level urban greenery. Methods: We collected meteorological and daily mortality data for 286 territory planning units between 2005 and 2018 in Hong Kong. Three greenery measurements were extracted for each unit: a) the normalized difference vegetation index (NDVI) from Landsat remote sensing images, b) the percentage of greenspace based on land use data, and c) eye-level street greenery from street view images via a deep learning technique. Time-series analyses were performed using the case time series design with a linear interaction between the temperature term and each of the three greenery measurements. Effect modifications were also estimated for different age groups, sex categories, and cause-specific diseases. Results: Higher mortality risks were associated with both moderate and extreme heat, with relative risks (RRs) of 1.022 (95% CI: 1.000, 1.044) and 1.045 (95% CI: 1.013, 1.079) at the 90th and 99th percentiles of temperatures relative to the minimum mortality temperature (MMT). Lower RRs were observed in greener areas whichever of the three greenery measurements was used, but the disparity of RRs between areas with low and high levels of urban greenery was more apparent when using eye-level street greenery as the index at high temperatures (99th percentile relative to MMT), with RRs for low and high levels of greenery, respectively, of 1.096 (95% CI: 1.035, 1.161) and 0.985 (95% CI: 0.920, 1.055) for NDVI (p=0.0193), 1.068 (95% CI: 1.021, 1.117) and 0.990 (95% CI: 0.906, 1.081) for the percentage of greenspace (p=0.1338), and 1.103 (95% CI: 1.034, 1.177) and 0.943 (95% CI: 0.841, 1.057) for eye-level street greenery (p=0.0186). Health discrepancies remained for nonaccidental mortality and cardiorespiratory diseases and were more apparent for older adults (≥65 years of age) and females. Discussion: This study provides new evidence that eye-level street greenery shows stronger associations with reduced heat–mortality risks compared with overhead-view greenery based on NDVI and percentage of greenspace. The effect modification of urban greenery tends to be amplified as temperatures rise and are more apparent in older adults and females. Heat mitigation strategies and health interventions, in particular with regard to accessible and visible greenery, are needed for helping heat-sensitive subpopulation groups in coping with extreme heat. https://doi.org/10.1289/EHP12589


Figure S2.
Maps of three urban greenery measurements at the TPU level in Hong Kong: A) NDVI; B) percentage of greenspace; C) eye-level street greenery (%).The maps were created by using ArcGIS 10.5.1 (ESRI) and included data for 286 TPUs.Descriptive statistics of three urban greenery indicators are included in Table 1.Note: TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index.

Figure S3.
Pearson's correlation coefficients between socio-economic variables and three urban greenery measurements.

Figure S4.
The age-specific overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95th percentile, dashed lines in light green) value of NDVI, percent of greenspace, and eyelevel street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of older adults (age≥65 years, N=175,658) and young people (0-64 years, N= 46,230) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90th and 99th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel Table S4.Note: RRs: relative risks; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index.

Figure S5.
The gender-specific overall cumulative exposure-response associations between summer temperatures and mortality predicted by an extended CTS model for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percent of greenspace, and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of females (N=99,509) and males (N=122,408) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel Table S5.Note: RRs: relative risks; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index.

Figure S6.
The cause-specific overall cumulative exposure-response associations between summer temperatures and mortality predicted by an extended CTS model for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percent of greenspace, and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes data with TPU identifiers (3-digit TPU code) of mortality caused by non-accidental diseases (N= 213,505) and cardiorespiratory diseases (N= 93,974) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel Table S6.Note: RRs: relative risks; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index.

Figure S7
. The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in older adults (age≥65 years), expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of older adults from June to October within the study period 2005-2018 (N=175,658).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S8
. The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in females, expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of female from June to October within the study period 2005-2018 (N=99,509).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S9
. The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in non-accidental mortality, expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes non-accidental mortality data with TPU identifiers (3-digit TPU code) from June to October within the study period 2005-2018 (N= 213,505).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S10
. The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in cardiorespiratory diseases, expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes data with TPU identifiers (3-digit TPU code) of mortality caused by cardiorespiratory diseases from June to October within the study period 2005-2018 (N= 93,974).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S11.
The overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace, and eye-level street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes all-cause mortality data with TPU identifiers (3-digit TPU code) from June to October within the study period 2005-2018 (N=221,919).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel Table S7.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Figure S12.
The age-specific overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of older adults (age≥65 years, N=175,658) and young people (0-64 years, N= 46,230) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel Table S8.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Figure S13.
The gender-specific overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eyelevel street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of females (N=99,509) and males (N=122,408) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel Table S9.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Figure S14.
The cause-specific overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eyelevel street greenery.The analysis includes data with TPU identifiers (3-digit TPU code) of mortality caused by non-accidental diseases (N= 213,505) and cardiorespiratory diseases (N= 93,974) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel Table S10.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.S8.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.S10.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Figure S1 .
Figure S1.A) Example of a four-image Google Street View panorama generated for a single point in Hong Kong, and B) the corresponding greenery extraction by a Python script using a deep learning technique of fully convolutional neural network.
2 percentage of people aged > 15 years with educational attainment only at primary school or below3 percentage of the working population with monthly income below the poverty line (i.e., HKD$2000 in 2006 and HKD$4000 in 2016 according to the poverty indicator in Hong Kong) 1 * Data for each variable were obtained from the 2006 and 2016 Hong Kong censuses. 2,3The smallest census units with available data in the two rounds of censuses were large TPUs, in which adjacent TPUs with small population were merged into a large unit.

Figure S1 .
Figure S1.A) Example of a four-image Google Street View panorama generated for a single point in Hong Kong, and B) the corresponding greenery extraction by a Python script using a deep learning technique of fully convolutional neural network.

Figure S2 .
Figure S2.Maps of three urban greenery measurements at the TPU level in Hong Kong: A) NDVI; B) percentage of greenspace; C) eye-level street greenery (%).The maps were created by using ArcGIS 10.5.1 (ESRI) and included data for 286 TPUs.Descriptive statistics of three urban greenery indicators are included in Table 1.Note: TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index.

Figure S3 .Figure S4 .
Figure S3.Pearson's correlation coefficients between socio-economic variables and three urban greenery measurements

Figure S5 .
Figure S5.The gender-specific overall cumulative exposure-response associations between summer temperatures and mortality predicted by an extended CTS model for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percent of greenspace, and eyelevel street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of females (N=99,509) and males (N=122,408) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel TableS5.Note: RRs: relative risks; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index.

Figure S6 .
Figure S6.The cause-specific overall cumulative exposure-response associations between summer temperatures and mortality predicted by an extended CTS model for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percent of greenspace, and eyelevel street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes data with TPU identifiers (3-digit TPU code) of mortality caused by non-accidental diseases (N= 213,505) and cardiorespiratory diseases (N= 93,974) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel TableS6.Note: RRs: relative risks; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index.

Figure S7 .
Figure S7.The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in older adults (age≥65 years), expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of older adults from June to October within the study period 2005-2018 (N=175,658).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S8 .
Figure S8.The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in females, expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of female from June to October within the study period 2005-2018 (N=99,509).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S9 .
Figure S9.The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in nonaccidental mortality, expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes non-accidental mortality data with TPU identifiers (3-digit TPU code) from June to October within the study period 2005-2018 (N= 213,505).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S10 .
Figure S10.The estimated interactions between three urban greenery indicators and the overall cumulative heat-mortality associations in cardiorespiratory diseases, expressed by the ratio of RRs between TPUs with a low (5 th percentile) and high (95 th percentile) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, with 95% confidence intervals shown in shaded areas.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes data with TPU identifiers (3-digit TPU code) of mortality caused by cardiorespiratory diseases from June to October within the study period 2005-2018 (N= 93,974).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results are available upon request from the corresponding author.Note: RRs, relative risks; TPU, Tertiary Planning Units; NDVI, normalized difference vegetation index.

Figure S11 .
Figure S11.The overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace, and eyelevel street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes all-cause mortality data with TPU identifiers (3-digit TPU code) from June to October within the study period 2005-2018 (N=221,919).The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel TableS7.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Figure S12 .
Figure S12.The age-specific overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of older adults (age≥65 years, N=175,658) and young people (0-64 years, N= 46,230) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel TableS8.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Figure S13 .
Figure S13.The gender-specific overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes mortality data with TPU identifiers (3-digit TPU code) of females (N=99,509) and males (N=122,408) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel TableS9.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Figure S14 .
Figure S14.The cause-specific overall cumulative exposure-response associations between summer temperatures and mortality for a TPU with a low (5 th percentile, solid lines in light purple) and high (95 th percentile, dashed lines in light green) value of NDVI, percentage of greenspace and eye-level street greenery in Hong Kong, 2005-2018, after controlling the effects of daily relative humidity, O3 and PM10 concentrations at 0-1 lag days, with 95% confidence intervals shown in shaded areas, and p-value for the interaction term.The corresponding values to the low (5 th percentile) and high (95 th percentile) levels of each urban greenery indicator are 0.15 and 0.69 for NDVI, 0.01% and 97.77% for % of greenspace, and 0.02% and 66.35% for the eye-level street greenery.The analysis includes data with TPU identifiers (3-digit TPU code) of mortality caused by non-accidental diseases (N= 213,505) and cardiorespiratory diseases (N= 93,974) from June to October within the study period 2005-2018.The estimation results were predicted by an extended CTS model specifying an interaction between the cross-basis of temperature and each urban greenery metric and using data aggregated at the TPU level (286 TPUs).Numeric results at the 90 th and 99 th percentiles of temperatures (30.1°C and 30.9°C) by a low and high value of each urban greenery indicator are included in Excel TableS10.Note: RR, relative risk; TPU: Tertiary Planning Units; NDVI: normalized difference vegetation index; O3, ozone; PM10, particular matter with a diameter of 10 microns or less.

Table of ContentsTable S1 .
Descriptive statistics of size, population and socioeconomic variables in Hong Kong, 2005-2018.

Table S1 .
Descriptive statistics of size, population and socioeconomic variables in Hong Kong, 2005-2018.