So I looked at pollution data provided by the World Bank. Although just two years' data cannot show any meaningful direction for further explanation, the global particle pollution seems getting worse. The global mean annual exposure increased from 29.9 µg/m3 in 2005 to 31.3 µg/m3 in 2010. Pollution from industrial and transport sectors might be the main cause.
However, there is one important condition that we can easily overlook. Although countries with vast area of deserts recorded higher pollution levels, the effects of natural dust and sea salt should be removed to better assess the health impacts of PM2.5. So, after the final PM2.5 concentration map from SEDAC below (Figure 1), I am introducing additional images (Figure 2) from a recent study (van Donkelaar et al., 2015) that used the same satellite observation data.
Table. PM2.5 Pollution (mean annual exposure)
Unit: µg/m3
Country | 2005 | 2010 |
United Arab Emirates | 65.68166 | 79.51939 |
China | 63.99531 | 72.56515 |
Qatar | 59.87048 | 69.02888 |
Mauritania | 69.93466 | 65.18214 |
Saudi Arabia | 62.20242 | 61.68340 |
Kuwait | 49.41866 | 50.39333 |
Bahrain | 48.01391 | 49.33072 |
Turkmenistan | 48.76600 | 48.28830 |
Cabo Verde | 43.36331 | 42.86366 |
Senegal | 41.36001 | 41.19929 |
Pakistan | 37.28355 | 38.10374 |
Korea, South | 40.09238 | 37.52048 |
Libya | 36.42195 | 37.18039 |
Niger | 37.36272 | 36.82437 |
Gambia, The | 35.93841 | 35.75570 |
Oman | 34.12933 | 35.29841 |
Mali | 34.62133 | 34.11404 |
Chad | 34.03407 | 33.35825 |
Nepal | 30.66388 | 32.66240 |
Egypt, Arab Rep. | 33.59428 | 32.58492 |
India | 31.46866 | 32.02058 |
Korea, North | 30.72270 | 31.51703 |
World | 29.86480 | 31.25349 |
Guinea-Bissau | 31.11515 | 31.21841 |
Bangladesh | 29.84423 | 31.13156 |
Iraq | 30.63495 | 30.39379 |
Yemen, Rep. | 30.81548 | 30.16242 |
Vietnam | 28.87354 | 29.80268 |
Iran, Islamic Rep. | 30.02963 | 29.69507 |
Jordan | 29.53331 | 28.77559 |
Burkina Faso | 27.48525 | 27.35054 |
Nigeria | 26.93633 | 27.07458 |
Djibouti | 26.51410 | 26.83520 |
Israel | 26.88058 | 26.18212 |
Syrian Arab Republic | 26.77977 | 25.99799 |
Sudan | 26.07869 | 25.86403 |
West Bank and Gaza | 26.06656 | 25.37601 |
Eritrea | 24.44714 | 24.53869 |
Afghanistan | 24.32812 | 23.89933 |
Lebanon | 24.58599 | 23.79930 |
Lao PDR | 21.19542 | 22.45218 |
Guinea | 22.65570 | 22.28595 |
Cameroon | 22.08601 | 22.17291 |
Uzbekistan | 23.72026 | 22.10496 |
Algeria | 22.43683 | 22.04645 |
Benin | 22.20245 | 21.92649 |
Japan | 22.79315 | 21.81006 |
Myanmar | 21.72509 | 21.77255 |
Bhutan | 20.19818 | 21.72453 |
Malta | 22.76602 | 21.30753 |
Thailand | 20.87660 | 21.07797 |
Togo | 21.33735 | 20.98064 |
Morocco | 20.13554 | 19.97916 |
Singapore | 20.85270 | 19.82913 |
Barbados | 19.47597 | 19.41978 |
Central African Republic | 19.76822 | 19.21593 |
Italy | 21.74040 | 19.04609 |
Tunisia | 19.76945 | 19.04604 |
Cyprus | 19.76426 | 18.96764 |
Belgium | 22.08128 | 18.80821 |
Armenia | 19.92665 | 18.73134 |
Netherlands | 21.72581 | 18.54935 |
Ghana | 18.37616 | 18.01068 |
Dominica | 17.78881 | 17.98825 |
St. Lucia | 18.18060 | 17.96446 |
Sierra Leone | 17.85903 | 17.63314 |
Antigua and Barbuda | 17.41343 | 17.45214 |
Turkey | 18.49803 | 17.44953 |
Cambodia | 17.54926 | 17.43361 |
Azerbaijan | 18.74119 | 17.28889 |
Romania | 20.75279 | 17.25078 |
St. Vincent and the Grenadines | 17.39695 | 17.09740 |
Greece | 18.90921 | 16.89706 |
Macedonia, FYR | 19.14504 | 16.85793 |
Bulgaria | 19.53040 | 16.81881 |
Tajikistan | 18.57619 | 16.68379 |
Mexico | 16.83631 | 16.64726 |
Hungary | 19.84951 | 16.24823 |
Kyrgyz Republic | 18.22999 | 15.98221 |
Montenegro | 18.57360 | 15.89186 |
Serbia | 18.57360 | 15.89186 |
Germany | 19.04302 | 15.85773 |
Poland | 18.98603 | 15.78261 |
Maldives | 15.19199 | 15.75179 |
Czech Republic | 19.45999 | 15.66124 |
Ethiopia | 15.39432 | 15.41976 |
Grenada | 16.07247 | 15.27145 |
Cote d'Ivoire | 15.46996 | 15.24135 |
Slovenia | 17.64982 | 15.23634 |
Congo, Dem. Rep. | 15.12717 | 15.13202 |
Slovak Republic | 18.22347 | 15.00319 |
Croatia | 16.92603 | 14.36613 |
France | 15.61563 | 14.33079 |
Albania | 16.41100 | 14.29622 |
Rwanda | 14.13845 | 14.16464 |
Congo, Rep. | 14.78158 | 14.02519 |
Spain | 14.81681 | 13.98518 |
Switzerland | 15.91973 | 13.86089 |
Indonesia | 13.93691 | 13.80772 |
Moldova | 16.84122 | 13.79449 |
United Kingdom | 14.91859 | 13.70214 |
Kazakhstan | 13.17328 | 13.39266 |
United States | 13.73764 | 13.38303 |
Luxembourg | 15.67862 | 13.29090 |
Austria | 15.01844 | 13.22534 |
Bahamas, The | 13.24748 | 13.02847 |
Andorra | 13.67137 | 12.99452 |
Malaysia | 13.08630 | 12.94251 |
Ukraine | 15.49109 | 12.69998 |
Portugal | 11.77354 | 12.53817 |
Bosnia and Herzegovina | 13.42289 | 12.41069 |
Georgia | 11.77928 | 12.00855 |
Jamaica | 10.17643 | 11.96345 |
Guatemala | 10.63070 | 11.85139 |
Denmark | 11.53602 | 11.70216 |
Haiti | 12.10771 | 11.42943 |
Burundi | 11.49712 | 11.23896 |
Angola | 10.35762 | 11.23079 |
Belarus | 10.29214 | 10.64201 |
Lithuania | 7.88313 | 10.15811 |
Canada | 10.28616 | 10.14480 |
Uganda | 10.87613 | 10.03688 |
Peru | 10.16026 | 9.80432 |
Russian Federation | 8.75458 | 9.59945 |
Mongolia | 9.32179 | 9.20861 |
Latvia | 5.01399 | 9.14117 |
Dominican Republic | 9.56640 | 8.90070 |
Liberia | 8.21280 | 8.78300 |
Ireland | 7.04813 | 8.67139 |
Sri Lanka | 10.24467 | 8.61689 |
Somalia | 8.13699 | 8.21147 |
Costa Rica | 5.02749 | 8.19678 |
Chile | 8.12389 | 8.13966 |
Venezuela, RB | 6.27769 | 8.09122 |
Marshall Islands | 5.08027 | 7.85952 |
South Africa | 7.20781 | 7.80041 |
Estonia | 5.00164 | 7.24874 |
Philippines | 6.96318 | 7.06607 |
Cuba | 6.85605 | 6.94057 |
Equatorial Guinea | 7.34036 | 6.85246 |
Honduras | 6.70937 | 6.72552 |
Kiribati | 6.34917 | 6.42433 |
Guyana | 6.36976 | 6.26987 |
Gabon | 6.36254 | 6.09124 |
Bolivia | 5.85383 | 6.04628 |
Sweden | 5.85217 | 5.99107 |
Lesotho | 5.00127 | 5.93226 |
Kenya | 5.08719 | 5.84695 |
Iceland | 5.68715 | 5.83887 |
Solomon Islands | 5.02314 | 5.81406 |
Uruguay | 5.00428 | 5.80678 |
Australia | 5.01004 | 5.68590 |
Zambia | 5.08932 | 5.63978 |
Ecuador | 5.83868 | 5.61844 |
New Zealand | 5.13576 | 5.58406 |
Belize | 5.45297 | 5.54806 |
Timor-Leste | 5.00523 | 5.44113 |
Tanzania | 5.29027 | 5.42503 |
Colombia | 5.26264 | 5.40619 |
Brunei Darussalam | 5.01483 | 5.40484 |
Papua New Guinea | 5.00340 | 5.37060 |
Fiji | 5.02250 | 5.35870 |
Nicaragua | 5.09545 | 5.34375 |
Panama | 5.00599 | 5.30016 |
El Salvador | 5.05292 | 5.24743 |
Seychelles | 4.92666 | 5.24212 |
Finland | 4.99448 | 5.22406 |
Madagascar | 5.00159 | 5.21810 |
Vanuatu | 5.00859 | 5.21081 |
Botswana | 5.00322 | 5.16612 |
Tonga | 5.08818 | 5.14790 |
Mozambique | 4.99959 | 5.11382 |
Mauritius | 5.09764 | 5.07905 |
Brazil | 5.25013 | 5.07802 |
Suriname | 5.29545 | 5.05235 |
Argentina | 5.21216 | 4.98674 |
Sao Tome and Principe | 4.95706 | 4.97077 |
Samoa | 4.99461 | 4.92124 |
Swaziland | 5.00995 | 4.91671 |
Malawi | 5.00105 | 4.87758 |
Zimbabwe | 5.00225 | 4.77891 |
Comoros | 4.95402 | 4.72747 |
Micronesia, Fed. Sts. | 4.99973 | 4.69715 |
Paraguay | 5.00445 | 4.47555 |
Namibia | 5.25051 | 4.44832 |
Norway | 5.56339 | 4.40615 |
Trinidad and Tobago | 5.26734 | 4.39580 |
Figure 1. Global Annual Average PM2.5 Grids (2001–2010).
Source: SEDAC, 2013
Figure 2. Comparison of PM2.5 concentration with and without natural dust and sea salt (2001–2010).
Source: van Donkelaar et al., 2015
References:
Hamra, G. B., et al. (2014). Outdoor Particulate Matter Exposure and Lung Cancer: A Systematic Review and Meta-Analysis. Environmental Health Perspectives, 122(9), 906–911. DOI: 10.1289/ehp/1408092. [Full-text at http://dash.harvard.edu/bitstream/handle/1/12987239/4154221.pdf]
Rohde, R. A., & Muller, R. A. (2015). Air Pollution in China: Mapping of Concentrations and Sources. PLoS ONE, 10(8), e0135749. [Full-text at http://dx.doi.org/10.1371/journal.pone.0135749]
Socioeconomic Data and Applications Center (SEDAC). (2013). Global Annual Average PM2.5 Grids from MODIS and MISR Aerosol Optical Depth (AOD), v1 (2001 – 2010). [Map image at http://sedac.ciesin.columbia.edu/data/set/sdei-global-annual-avg-pm2-5-2001-2010]
van Donkelaar, A., Martin, R. V., Brauer, M., & Boys, B. L. (2015). Use of Satellite Observations for Long-Term Exposure Assessment of Global Concentrations of Fine Particulate Matter. Environmental Health Perspectives, 123(2), 135–143. [Full-text at http://dx.doi.org/10.1289/ehp.1408646]