Supplementary Materials

Environmental risk and housing price: an empirical study of

Nanjing, China

Jing Dai 1, Peichen Lv 1, Zongwei Ma 1, Jun Bi 1, *, Ting Wen 2, *

1 State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment,

Nanjing University, Nanjing, Jiangsu, China

2 School of Business Administration, Nanjing University of Finance and Economics, Nanjing,

Jiangsu, China

*Correspondence to:

Dr. Jun Bi, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing

210023, China. E–mail address: jbi@nju.edu.cn;

Dr. Ting Wen, School of Business Administration, Nanjing University of Finance and

Economics, 3 Wenyuan Road, Nanjing 210023, China. E–mail address: wen5ting@163.com.

1

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

1

Figure S1. Research framework

Table S1. Residence samples used in this study

District Community number Number of residence sample

Gulou

184 367

Xuanwu

Qixia

Qinhuai

Jianye

Yuhuatai

Pukou 146 292

Luhe 142 284

Jiangning 164 291

2

17

18

19

20

21

2

Table S2. Environmental risks of Nanjing’s chemical enterprises

ID EnterpriseAccident

type

Death radius(m)

Risk value Within the

death radius

Radius of

serious injury(m)

Risk value Between the

death and serious

injury radius1 Red Sun Chemicals Leakage 3000 4.71 ×10−2 3500 9.42 ×10−5

2Keliya Polyol Co., Ltd.

CO release

350 3.01 ×10−3 400 6.03 ×10−5

3Huisheng Chemicals

CO release

2000 9.84 × 10−2 2500 1.97 ×10−4

4Nanjing Thermoelectricity Co., Ltd.

CO release

50 6.15 ×10−5 100 1.23 ×10−6

5 Taihua Chemicals Leakage 1000 5.23 ×10−3 1500 1.05 ×10−5

6 Nanjing Pharmaceutical Leakage 1000 5.23 ×10−3 2000 5.23 ×10−6

7Yabao Chemicals

CO release

200 9.84 × 10−4 300 9.84 × 10−6

8 Dena Chemicals Leakage 2500 3.27 ×10−2 3000 6.54 × 10−5

9Jinpu Rubber Co., Ltd.

CO release

900 1.99 ×10−2 1000 1.99 ×10−4

10 Nanjing Weier Chemicals Leakage 1000 5.23 ×10−3 1500 1.05 ×10−5

11 Nanjing Baochun Chemicals Leakage 2500 3.27 ×10−3 3000 6.54 × 10−5

12 Desida Paint Co., Ltd. Leakage 500 1.31 ×10−3 600 1.31 ×10−5

13Nanjing Yudeheng Co., Ltd.

CO release

300 2.21 ×10−3 800 4.43 × 10−6

14Sasuo Chemicals

CO release

600 8.86 ×10−3 700 8.86 ×10−5

15 Nanjing Red Sun Changjiang Paint Co., Ltd.

CO release

400 3.94 ×10−3 500 3.94 ×10−5

16Nanjing Fuchang Chemicals and

Residue Treatment Co., Ltd.CO

release600 8.86 ×10−3 700 8.86 ×10−5

17Nanjing Jinpujinhu Chemicals

CO release

1500 5.54 ×10−2 2000 1.11×10−4

18 Nanjing Alkylbenzene Plant Leakage 1300 3.04 ×10−1 1800 6.07 ×10−4

19 Jiahe Chemical Leakage 1300 3.04 ×10−1 1800 6.07 ×10−4

20 Jintung Petrochemical Co. Ltd. Leakage 1300 3.04 ×10−1 1800 6.07 ×10−4

21 Jintung Chemical Leakage 1300 3.04 ×10−1 1800 6.07 ×10−4

3

22

23

3

Text S1. Description of information diffusion method

A trapezoidal fuzzy model is used in the information diffusion method to calculate the

regional environmental risks (Meng et al., 2014) as follows:

r={ r0 0<x< l'

r0

l−l' l '< x≤ l

0x>l

(S-1)

where r is the calculated risk value at a certain point (e.g., at a given distance from a risk

source), r0 represents the environmental risk value of the risk source, x is the distance from a

certain point to the risk source, l ' is the maximum radius of death influence in the dominant

wind direction, and l is the maximum radius of serious injury influence in the dominant wind

direction. The values of l' and l can be determined by the calculated distance from the risk

source at which the predicted concentration equals the threshold value for the dangerous, i.e.,

the lethal concentration required to kill 50% of a population (LC50), and immediately

dangerous to life or health (IDLH). r0 can be calculated as follows:

r0=P× C (S-2)

where P represents the probability of occurrence of an accident. The probability of

4.7 × 10−5 per year is used for occurrence of a fire disaster, 1.0×10−5 per year for a leakage

accident, and 1.93 ×10−6 per year for a hazardous material transportation accident. The value

C represents the harm caused by the accident, which can be calculated using the following

equation:

C=3.14 ×l2 ×d ×50 % (S-3)

where d represents the population density in the park, and 50% accounts for the fact that we used LC50 as the basis for calculating mortality.

4

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

4

Table S3. Risk ranking criteria of accidental environmental risk

Risk level Environmental risk (R)

5 R ≥1 ×10−3

4 1×10−4≤ R<1 ×10−3

3 1×10−5 ≤ R<1× 10−4

2 1 ×10−6 ≤ R<1× 10−5

1 1×10−7 ≤ R<1× 10−6

0 R¿1 ×10−7

Figure S2. Impact areas of liquid ammonia transient leakage on expressway estimated

using ALOHA software

5

47

48

49

50

51

52

5

Text S2. Calculation method of environmental risks of gas stations

S2.1 Calculation of fire risk area

The pool fire model is used to calculate the risk area of thermal radiation (Zhou and

Zhao, 2013):

The equivalent radius of liquid pool (r) is calculated as follows:

r=√ 3dLπ

(S-4)

d: diameter of gasoline tank, 2.8 m;

L: length of gasoline tank, 7.2 mm.

Flame height (h) of the pool fire is calculated as follows:

h=84 r [ dm /dtρ0 √2 gr ]

0.61

(S-5)

dm/dt: burning rate of gasoline, 0.0256 kg /(m2 ∙ s);

ρ0: density of ambient air, 1.19 kg /m3.

The formula of thermal flux (Q):

Q=( π r2+2πrh ) dm

dtηΔHc

72( dmdt )

0.61

+1 (S-6)

where η is the efficiency factor, 0.24, and ΔHc is combustion heat, 43730 J/kg.

The risk distances (x) for different thermal flux thresholds are:

x=√ Qt c

4 πI (S-7)

where t c is the coefficient of heat conduction, t c=1; the thermal flux threshold

I=12.5 kW /m2 for serious injury area; and I=4kW /m2 for maximum impact area.

6

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

6

S2.2 Calculation of explosion risk area

The amount of gasoline in a tank is calculated as the maximum designed amount (Zhou

and Zhao, 2013). The TNT equivalent of a gas station:

W TNT=α W f Q f

QTNT (S-8)

α: equivalent coefficient of vapor cloud, 0.04;

Wf: gasoline storage, kg;

Qf: is combustion heat of gasoline, 43730 J/kg;

QTNT: explosion heat of TNT, 4520 kJ/kg.

The impact radius (R) is calculated as follows:

R=(8 W TNT /10 P )1/3 (S-9)

where P is hyper pressure. P=3.447 kPa for maximum impact radius and P=90 kPa for

serious injury radius.

S2.3 Environmental risks of gas stations

Based on on-site investigations and online map surveys, we screened 206 gas stations in

the study area. Among them, there are 31, 119, 52, and 4 gas stations that have 2, 4, 6, and 8

filling machines, respectively. The gasoline storage amount for each station was estimated

according to a previous study (Li et al., 2011) and related environmental impact assessment

reports for gas stations. Table S4 shows the storage amount for each type of gas station.

Table S4. Oil reserves of gas stations in Nanjing

Number of filling machines for a

station

Number of gas

stations

Number of gasoline

tanks

Maximum gasoline storage amount (t)

Number of diesel tanks

Maximum diesel storage amount (t)

2 31 1 39.5 1 454 119 2 79 2 906 52 3 118.5 2 908 4 4 158 3 135

The serious injury radius and maximum impact radius were calculated according to the

method in S2.1 and S2.2. The results are shown in Table S5. Then, the information diffusion

7

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

7

method in Text S1 was used to calculate the risks of gas stations. Then, gridded risk levels

were determined based on the ranking criteria (Table S3). The distribution of risk levels of

gas stations can be found in Figure 2(D).

Table S5. Environmental risk of gas stations in Nanjing

Number of

filling machine

s

Fire ExplosionSeriou

s injury radius

Maximum impact

radius

Risk in serious injury radius

Risk in maximu

m impact radius

serious

injury radius

maximum

impact radius

serious

injury radius

maximum

impact radius

2 7.83 13.84 5.14 15.25 7.83 15.25 6.64×10-7 8.95×10-8

4 7.83 13.84 6.48 19.22 7.83 19.22 5.51×10-6 4.84×10-7

6 7.83 13.84 7.41 22.00 7.83 22.00 5.51×10-6 3.89×10-7

8 7.83 13.84 8.16 24.21 8.16 24.21 5.51×10-6 3.43×10-7

Text S3. Calculation method of PM2.5 health risks

We selected stroke (STK), ischemic heart disease (IHD) and lung cancer (LC) as health

endpoints to calculate the excess deaths (ED) attributable to outdoor PM2.5 exposure:

ED=(1− 1RR )× B× P (S-10)

where P is the population exposed to a certain level of PM2.5; B is the baseline mortality,

which can be obtained from the database of Global Burden of Diseases

(http://www.healthdata.org/data-visualization/gbd-compare) (Table S6). RR is the relative

risk for different health endpoints, which can be calculated using the Integrated Exposure-

Response (IER) model (Burnett et al., 2014):

RR (C )=¿ (S-11)

where C0 represents the threshold at which health effects occur. The values for each

parameter were obtained from a previous study (Lee et al., 2015) and are shown in Table S7.

Table S6. Baseline mortality for health endpoints

Year IHD STK LC

2015 1.2439‰ 1.3085‰ 0.4306‰

8

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

8

Table S7. Coefficients in IER model

IHD STK LC

C0 (μg/m3) 6.96 8.38 7.24

α 0.843 1.01 159

γ 0.0724 0.0164 0.000119

δ 0.544 1.14 0.735

Figure S3. Excess deaths attributable to PM2.5 in Nanjing

Table S8. Ranking criteria of environmental risk of PM2.5 in Nanjing

Risk level Excess deaths (ED)

5 6.008<ED≤7.510

9

111

112

113

114

115

116

9

4 4.506<ED≤6.008

3 3.004<ED≤4.506

2 1.502<ED≤3.004

1 0.000<ED≤1.502

0 ED=0.000

Text S4. Calculation method of health risks of heavy metal pollution in the soil

S4.1 Method for exposure assessment

We used China’s Technical Guidelines for Risk Assessment of Contaminated Sites (HJ

25.3-2014) (MEP, 2014) to assess the health risk of heavy metal pollution in the soil.

Exposure doses of heavy metals in the soil for carcinogenic effects were calculated using

formulas S-12~S-14, while exposure doses for noncarcinogenic effects were calculated using

formulas S-15~S-17.

(S-12)

(S-13)

(S-14)

(S-15)

(S-16)

(S-17)

where Ding, Ddermal, and D¿ h are the average daily intakes (mg/kg/day) of heavy metals

for ingestion, dermal absorption, and inhalation, respectively; C sur is the heavy metal

concentration in the soils in Nanjing (mg/kg); OSIRc and OSIRa are the ingestion rates for

children (100 mg/day) and adults (200 mg/day), respectively; BW c and BW a are the average

10

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

10

body weights for children (15.9 kg) and adults (56.8 kg), respectively; |¿0|¿ is the dermal

absorption factor (unitless), which is 0.001; AT ca and AT nc are the average exposure time, for

noncarcinogens, 2190 days; for carcinogens, 26280 days; EDc and EDaare the exposure

duration, 6 years for children and 24 years for adults, respectively; SSARc and SSARa are

adherence rates of soil on skin for children (0.2 mg/cm2) and adults (0.07 mg/cm2),

respectively; SAEc and SAEa are exposed skin areas (cm2) for children (2448 cm2) and adults

(5075 cm2), respectively; E v is the daily exposure frequency of dermal contact (1 time/day);

PM10 is the content of inhalable particles (0.15 mg/cm3); DAIRc and DAIRa are daily

inhalation rates for children (7.5 m3/d) and adults (14.5 m3/d), respectively; PIAF is the

retention fraction of inhaled particles, 0.75; f spi and f spo are fractions of soil-borne particles in

indoor (0.8) and outdoor air (0.5), respectively; EFIc and EFIa are indoor exposure

frequencies (both are 262.5 days/year); and EFOc and EFOa are outdoor exposure frequencies

(both are 87.5 days/year). Concentrations of heavy metals (Pb, Zn, Cr, and Cd) in the topsoil

in Nanjing, China, were collected from the literature (Chen et al., 2008; Chu and Luo, 2010;

Ding et al., 2011; Dong, 2015; Duan et al., 2010; Li et al., 2008; Li et al., 2014; Liu et al.,

2014; Liu, 2013; Song et al., 2017; Yu et al., 2014; Zhou et al., 2010; Zhu et al., 2014).

S4.2 Methods for health risk assessment

The carcinogenic risk (CR) and noncarcinogenic hazard quotient (HQ) for single heavy

metals and single exposure pathways are calculated as follows:

CR=D j× SF j (S-18)

HQ=D j

R f D j × SAF (S-19)

where SAF is the soil allocation factor, 0.2. Reference doses for noncarcinogenic risk (

R f D j) and slope factors for carcinogenic risk (SF j) can be seen in Table S9.

Table S9. Reference doses of soil heavy metal exposure

元素RfDinh

(×10−3)

RfDing

(×10−3)

RfDdermal

(×10−3)SFinh SFing SFdermal

Cd 1.00 1.00 0.01 6.30 - -Cr 3.00 3.00 0.06 0.5 - -

11

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

11

Pb 35.00 3.50 0.53 - - -Zn 300.00 300.00 60.00 - - -

The carcinogenic risk (CRn) and noncarcinogenic hazard index (HIn) for three exposure

pathways for a single heavy metal can be calculated as follows:

CRn=∑j=1

3

CR j (S-22)

HIn=∑j=1

3

HQ j (S-23)

Then, the total carcinogenic risk (CRT) and noncarcinogenic hazard index (HIT) are

calculated as the sum of CRn and HIn for all heavy metals:

CRT=∑n=1

4

CRn (S-24)

HIT=∑n=1

4

HI n (S-25)

Table S10. Rating criteria of non-carcinogenic risk of soil heavy metals

Grade of risk Hazard index (HI)

5 2.404<HI≤2.600

4 2.208<HI≤2.404

3 2.012<HI≤2.208

2 1.816<HI≤2.012

1 1.620<HI≤1.816

0 HI=0.000

Table S11. Regression results for models excluding the variable of accidental environmental risk of expressways

Variables Model 5 Coefficient Model 6 Coefficient Model 7 CoefficientIntercept 9.62 *** 9.36 *** 9.49 ***dis_CBD -2.32×10-5 *** -2.22×10-5 *** -2.14×10-5 ***dis_bus 4.09×10-5 5.61×10-5 4.52×10-5

dis_sub -3.65×10-5 *** -3.13×10-5 *** -3.16×10-5 ***area 1.40×10-3 *** 1.21×10-3 *** 1.18×10-3 ***room 6.19×10-4 5.18×10-4 1.94×10-5

age 2.51×10-3 -9.35×10-4 -1.74×10-3

12

159

160

161

162

163

164

165

166

167

168

169170

12

floor -4.32×10-4 -4.61×10-4 -3.19×10-4

fee 1.10×10-1 *** 9.06×10-2 *** 9.09×10-2 ***vol 1.15×10-2 3.69×10-3 2.66×10-3

green 4.76×10-3 *** 4.36×10-3 *** 4.20×10-3 ***type -8.27×10-2 ** -7.21×10-2 ** -7.02×10-2 **

decoration 4.57×10-2 *** 4.52×10-2 *** 4.43×10-2 ***unit_kindergarten 2.89×10-2 3.81×10-2 3.73×10-2

unit_primary 1.21×10-3 -3.55×10-3 3.07×10-3

unit_secondary 4.00×10-2 * 6.10×10-2 *** 6.13×10-2 **unit_hospital 7.09×10-2 ** 4.59×10-2 * 3.95×10-2 (P=0.05)

unit_supermarket 2.49×10-3 1.69×10-2 1.42×10-2

unit_shopping 7.14×10-3 -4.24×10-3 -6.44×10-3

unit_landscape 4.83×10-2 * 5.03×10-2 * 5.69×10-2 **R_total 6.09×10-2 (P=0.06) 8.75×10-1 *** /

(R_total)2 / -1.95×10-1 *** /R_chemical / / -3.77×10-2 *

R_gas / / -4.88×10-1 (P=0.053)R_highway (Excluded) / / /

R_soil / / 4.91×10-2 R_PM25 / / 6.90×10-2 ***

Model R2 0.582 0.610 0.618

* P<0.05; ** P<0.01; *** P<0.001References

Burnett, R.T., Pope, C.A., III, Ezzati, M., Olives, C., Lim, S.S., Mehta, S., Shin, H.H., Singh, G., Hubbell, B., Brauer, M., Anderson, H.R., Smith, K.R., Balmes, J.R., Bruce, N.G., Kan, H., Laden, F., Pruess-Ustuen, A., Turner, M.C., Gapstur, S.M., Diver, W.R., Cohen, A., 2014. An Integrated Risk Function for Estimating the Global Burden of Disease Attributable to Ambient Fine Particulate Matter Exposure. Environmental Health Perspectives 122(4), 397-403.

Chen, F., Yin, C., Jiang, X., Zhang, H., Wang, F., 2008. Evaluation of heavy metal pollution in representative vegetable soils in Nanjing based on GIS. Environmental Monitoring in China 24(2), 40-45. (in Chinese with English abstract).

Chu, B., Luo, L., 2010. Evaluation of heavy metal pollution in soils from Nanjing Qixiashang Lead-Zinc Mines. Rock and Mineral Analysis 29(1), 5-8. (in Chinese with English abstract).

Ding, A., Liu, C., Chen, C., Zhang, Y., Shao, J., 2011. Content of heavy metals of road greenbelt soil in Nanjing City and pollution evaluation. Urban Environment and Urban Ecology 24(4), 17-19. (in Chinese with English abstract).

Dong, L., 2015. Accumulation, sources and ecological effect of heavy metals in multi-medium along Yangtze River of Nanjing. Master's thesis, Nanjing Univsersity of Information Science and Technology (in Chinese with English abstract).

Duan, X., Cai, H., Cao, W., 2010. Study on the characteristics and the origin of heavy metal pollution in different functional regions of Nanjing. Environmental Science and Management 35(10), 31-34, 77. (in Chinese with English abstract).

13

171172

173174175176177178179180181182183184185186187188189190191

13

Lee, C.J., Martin, R.V., Henze, D.K., Brauer, M., Cohen, A., Donkelaar, A.v., 2015. Response of Global Particulate-Matter-Related Mortality to Changes in Local Precursor Emissions. Environmental Science & Technology 49(7), 4335-4344.

Li, D., Jin, Y., Zhang, J., Ruan, H., 2008. Heavy metal soil pollution in the Qinhuai River riparian zone. Journal of Zhejiang Forestry College 25(2), 228-234. (in Chinese with English abstract).

Li, Q., Song, W., Xie, F., Chen, Z., 2011. The mathematical simulation of fire and explosion accidents on damage scope in the gas station's oil storage tank area. Acta Scientiarum Naturalium Universitatis Nankaiensis 44(5), 7-13. (in Chinese with English abstract).

Li, S., Yang, J., Ruan, X., Zhang, G., 2014. Atmospheric deposition of heavy metals and their impacts on soil environmentin in typical urban areas of Nanjing. China Environmental Science 34(1), 22-29. (in Chinese with English abstract).

Liu, E., Yan, T., Birch, G., Zhu, Y., 2014. Pollution and health risk of potentially toxic metals in urban road dust in Nanjing, a mega-city of China. Science of The Total Environment 476-477, 522-531.

Liu, F., 2013. Health risk assessment and eco-toxicological diagnosis of contaminated soil of typical industrial district. Master's thesis, Nanjing Univsersity (in Chinese with English abstract).

Meng, X., Zhang, Y., Yu, X., Bai, J., Chai, Y., Li, Y., 2014. Regional environmental risk assessment for the Nanjing Chemical Industry Park: an analysis based on information-diffusion theory. Stochastic environmental research and risk assessment 28(8), 2217-2233.

MEP, 2014. Technical guidelines for risk assessment of Contaminated sites (HJ 25.3-2014). Ministry of Environmental Protection of China.

Song, J., Zhou, Q., Jiang, X., Zhao, H., Liang, Y., Luo, Y., Wang, Q., Zhao, L., 2017. GIS-based heavy metals risk assessment of agricultural soils-A case study of Baguazhou, Nanjing. Acta Pedologica Sinica 54(1), 81-90. (in Chinese with English abstract).

Yu, A., Lu, X., Zhou, S., Tong, L., 2014. Characteristics of heavy metals in the soil of different urban areas-A case study of Xuanwu District in Nanjing. Forest Engineering 30(6), 27-32. (in Chinese with English abstract).

Zhou, D., Zhao, N., 2013. On hazardous areas of fire and explosion for storage tank in the filling station. Journal of Wuhan Institute of Technology 35(1), 7-11. (in Chinese with English abstract).

Zhou, W., Li, R., Yue, H., Xie, X., Zhu, H., Shen, S., 2010. Concentrations and spatial distribution characteristics of available heavy metals in vegetable soils in Jiangbei Area of Nanjing City. Journal of Agro-Environment Science 29(3), 451-457. (in Chinese with English abstract).

Zhu, W., Zhang, Y., Wang, W., Wang, W., Tang, Q., Wu, J., 2014. Study on environmental investigation and impact assessment for heavy metal contaminated sites - A case of Shangfang Electroplating Factory. Proceedings of 4th Seminar on Heavy Metal Pollution Control and Risk Assessment., 251-257. (in Chinese).

14

192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226

227

14