Figure 1
Map of Iran in the world and location of studied metropolises (studied cities given by black dots).
Table 1
Population (SCI 2011), Latitude and longitude of eight major Iranian cities.
| City | Exposed population* | Latitude | Longitude |
|---|---|---|---|
| Tehran | 9000000 | 35.34 | 51.25 |
| Mashhad | 2750000 | 36.31 | 59.58 |
| Tabriz | 1495000 | 38.08 | 46.28 |
| Isfahan | 1987000 | 32.68 | 51.64 |
| Shiraz | 1540000 | 29.62 | 52.52 |
| Ahwaz | 1112000 | 31.32 | 48.68 |
| Arak | 484000 | 34.09 | 49.7 |
| Urmia | 680000 | 37.55 | 45.07 |
| Total population | 19048000 | – | – |
[i] * According to the report of statistical center of Iran.
Figure 2
Schematic applied in this study for data analysis.
Table 2
Relative risk with 95% confidence intervals and Baseline Incidence per 105 persons for each health impact estimates in the present study.
| Health endpoint | Baseline incidencea | PM10 RR (95% CI) per 10 μg/m3 | PM2.5 RR (95% CI) per 10 μg/m3 | |
|---|---|---|---|---|
| Mortality | Death (all cases) ICMb-9-CM o800 | 543.5 | 1.006 (1.004–1.008)c (Anderson et al., 2004; Fattore et al., 2011) | 1.015 (1.011–1.019) (Fattore et al., 2011; Organization. 2001) |
| Cardiovascular disease ICM-9-CM 390–459 | 231 | 1.009 (1.005–1.013) (Anderson et al., 2004; Fattore et al., 2011) | – | |
| Respiratory disease ICM-9-CM 460–519 | 48.4 | 1.013 (1.005–1.020) (Anderson et al., 2004; Fattore et al., 2011) | – | |
| Morbidity | HAd for cardiovascular disease | 436 | 1.009 (1.006–1.013) (Martuzzi et al., 2002; Organization. 2001) | – |
| HA for respiratory disease | 1260 | 1.008 (1.0048–1.0112) (Touloumi et al., 1996)[30] | – |
[i] a Crude rate per 100,000 inhabitants.
b International Classification of Diseases.
c Daily Average.
d Hospital Admission.
Table 3
PM10 concentrations (μg/m3) in eight megacities during 2011 to 2012.
| Parameter | Tehran | Mashhad | Tabriz | Isfahan | Shiraz | Ahwaz | Arak | Urmia |
|---|---|---|---|---|---|---|---|---|
| Annual mean | 70 | 84 | 75 | 127 | 86 | 193 | 91 | 90 |
| Winter mean1 | 62 | 85 | 70 | 115 | 87 | 185 | 81 | 83 |
| Summer mean2 | 79 | 82 | 80 | 138 | 93 | 198 | 102 | 96 |
| Annual 98 Percentile (P98) | 144 | 180 | 218 | 225 | 217 | 742 | 208 | 233 |
| Annual maximum | 289 | 296 | 400 | 337 | 330 | 2521 | 471 | 683 |
| Winter maximum | 169 | 296 | 400 | 254 | 330 | 2521 | 323 | 156 |
| Summer maximum | 289 | 277 | 321 | 337 | 294 | 764 | 471 | 683 |
| No. of station3 | 12 | 4 | 4 | 4 | 2 | 1 | 1 | 1 |
| Data capture (Day) | 365 | 362 | 365 | 365 | 362 | 262 | 351 | 270 |
[i] 1 Winter cool season: October to March.
2 Warm season: April to September.
3 Number of monitoring stations with valid data.
Table 4
PM2.5 (μg/m3) annual maximum concentration in the eight Iranian cities during 2011 to 2012.
| Tehran | 42 | Shiraz | 51 |
| Mashhad | 50 | Ahwaz | 115 |
| Tabriz | 45 | Arak | 55 |
| Isfahan | 76 | Urmia | 54 |
Table 5
Standards and guidelines for average ambient particulate concentration (μg/m3).
| Standard or guideline | PM10 (μg/m3) | PM2.5 (μg/m3) | ||
|---|---|---|---|---|
| annual | 24 hours | annual | 24 hours | |
| WHO guidelines (WHO 2005) | 20 | 50 | 10 | 25 |
| National Ambient Air Quality Standards(NAAQS) | 50 | 150 | 25 | 35 |
| Iran national standard | 20 | 50 | 10 | 25 |
| State of California | 20 | – | 12 | – |
| Other European countries | 20 | As low as possible | ||
| U.S.A Federal standard | – | – | 12 | – |
Figure 3
Annual mean variations of PM10 concentration (μg/m3) in 8 megacities based on average data.
Figure 4
Summary of descriptive statistics of PM10 concentrations (μg/m3) measured in 8 megacities stations during 2011 to 2012 (as a monthly average).
Figure 5
Percentage of person/days on which people in 8 metropolises of Iran are exposed to different concentrations of PM10.
Table 6
Estimated attributable proportion (AP) expressed as percentage and number of excess cases in a year due to short-term exposure per 10μg/m3 increase in the concentration of PM10.
| Health Endpoints | City | AP (uncertainty range) | No. of excess cases (uncertainty range) |
|---|---|---|---|
| Total mortality (TM) | Tehran Mashhad Tabriz Isfahan Shiraz Ahwaz Arak Urmia | 3.51 (2.37–4.63) 4.24 (2.87–5.58) 3.71 (2.5–4.89) 5.02 (3.4–6.58) 4.33 (2.92–5.69) 9.07 (6.24–11.74) 4.67 (3.17–6.14) 4.56 (3.08–5.99) | 1721 (1161–2268) 634 (429–834) 302 (204–398) 542 (368–711) 362 (245–476) 549 (377–710) 123 (83–161) 169 (114–221) |
| Cardiovascular mortality (CM) | Tehran Mashhad Tabriz Isfahan Shiraz Ahwaz Arak Urmia | 5.18 (2.94–7.32) 6.23 (3.56–8.76) 5.47 (3.11–7.71) 7.34 (4.22–10.28) 6.36 (3.63–8.93) 13.02 (7.68–17.78) 6.85 (3.92–9.6) 6.69 (3.83–9.38) | 1078 (613–1522) 396 (226–557) 189 (108–266) 337 (194–472) 226 (129–318) 335 (197–457) 77 (44–107) 105 (60–148) |
| Respiratory mortality (RM) | Tehran Mashhad Tabriz Isfahan Shiraz Ahwaz Arak Urmia | 7.32 (2.94–10.83) 8.76 (3.56–12.87) 7.71 (3.11–11.4) 10.28 (4.22–14.98) 8.93 (3.63–13.11) 17.78 (7.68–24.96) 6.9 (3.92–14.05) 9.38 (3.83–13.74) | 319 (129–472) 118 (48–173) 56 (23–83) 100 (41–145) 67 (27–98) 97 (42–135) 23 (9–33) 31 (13–46) |
| Hospital Admissions Cardiovascular Disease (HACD) | Tehran Mashhad Tabriz Isfahan Shiraz Ahwaz Arak Urmia | 5.18 (3.51–7.32) 6.23 (4.24–8.76) 5.47 (3.71–7.71) 7.37 (5.02–10.27) 6.36 (4.33–8.93) 13.02 (9.07–17.78) 6.58 (4.67–9.6) 6.69 (4.56–9.38) | 2035 (1381–2873) 747 (509–1050) 357 (242–502) 637 (435–890) 427 (291–600) 631 (440–862) 145 (99–202) 198 (135–278) |
| Hospital Admissions Respiratory Disease (HARD) | Tehran Mashhad Tabriz Isfahan Shiraz Ahwaz Arak Urmia | 4.63 (2.83–6.37) 5.58 (3.42–7.64) 4.89 (2.99–6.72) 6.58 (4.05–8.98) 5.69 (3.49–7.79) 11.74 (7.39–15.7) 6.14 (3.77–8.39) 5.99 (3.68–8.19) | 5258 (3215–7228) 1933 (1186–2648) 922 (562–1266) 1649 (1016–2249) 1105 (678–1512) 1646 (1036–2201) 375 (230–512) 514 (316–702) |
Table 7
Estimated attributable proportion (%AP) and mortality attributable to short-term exposure to PM2.5 concentration above 10μg/m3 (excluding accident causes) in 8 Iranian cities.
| Estimated no. of cases | 95% CL | Estimated % of cases | 95% CL | |||||
|---|---|---|---|---|---|---|---|---|
| Tehran | 2232 | 1657 | 2793 | 4.56 | 3.38 | a | 5.71 | b |
| Mashhad | 754 | 560 | 942 | 5.04 | 3.74 | 6.3 | ||
| Tabriz | 463 | 345 | 578 | 5.7 | 4.26 | 7.11 | ||
| Isfahan | 585 | 435 | 731 | 5.42 | 4.03 | 6.76 | ||
| Shiraz | 454 | 338 | 567 | 5.42 | 4.04 | 6.77 | ||
| Ahwaz | 787 | 598 | 963 | 13.01 | 9.88 | 15.93 | ||
| Arak | 165 | 123 | 205 | 6.26 | 4.67 | 7.8 | ||
| Urmia | 230 | 171 | 286 | 6.21 | 4.63 | 7.74 | ||
| Total | 5670 | 6.45 | ||||||
[i] a Obtained using the lower RR values.
b Obtained using the upper RR values.
Table 8
Summary of similar studies conducted in this field.
| Study (city) | Author, Year | Results |
|---|---|---|
| Attributable number of cases to PM Health outcomes | ||
| Two areas of Northern Italy | (Fattore et al., 2011) | In this study, PM2.5 had the highest health impact on the 24,000 inhabitants that caused an excess of total mortality of 8 out of 177 in a year. |
| Makkah | (Habeebullah, 2013) | The cumulative number of estimated average hospital admissions due to respiratory illnesses during the study period was 112,665 per 10μg/m3 increase of PM10 concentration. |
| U.S. 6 cities | (Laden et al., 2000) | In the combined analysis across the six cities, controlling for other sources, a 10μg/m3 increase in PM2.5 from mobile sources accounted for a 3.4% increase in daily mortality (CI, 1.7–5.2%). |
| Eight European cities | (Le Tertre et al., 2002) | Percentage increases associated with a 10μg/m3 increase in PM10 and 0.5% (95% CI: 0.2 to 0.8) for cardiac admissions of all ages. |
| Eight major Italian cities | (Martuzzi et al., 2002) | Results indicated that 4.7% of mortality (95% CI, 1.7–7.5) is attributable to PM10 concentrations higher than 30μg/m3. The numbers of attributable deaths were 3472. |
| 23 Italian cities | (Boldo et al., 2006) | The HIA estimated that 16,926 premature deaths from all causes, including 11,612 cardiopulmonary deaths and 1901 lung-cancer deaths, due to PM2.5 long-term exposure. |
| Ulaanbaatar, Mongolia | (Allen et al., 2013) | Estimated that 29% (95% CI, 12–43%) of cardiopulmonary deaths and 40% (95% CI, 17–56%) of lung cancer deaths in the city are attributable to outdoor air pollution. |
| 13 Italian cities | (Martuzzi et al. 2006) | Considering the short-term effects on mortality (within a week after exposure), the impact of PM10 above 20μg/m3 was 1372 deaths or 1.5% of the total mortality in the whole population. |
| European assessment (Austria, France and Switzerland) | (Künzli et al., 2000) | A study conducted in Austria, France and Switzerland has estimated air pollution caused 6% of total mortality, or more than 40,000 attributable cases, per year to PM10 in the 3 countries. |