RT Book, Section A1 Balmes, John R. A2 LaDou, Joseph A2 Harrison, Robert J. SR Print(0) ID 1104108671 T1 Outdoor Air Pollution T2 CURRENT Diagnosis & Treatment: Occupational & Environmental Medicine, 5e YR 2013 FD 2013 PB McGraw-Hill Education PP New York, NY SN 9780071808156 LK accessmedicine.mhmedical.com/content.aspx?aid=1104108671 RD 2024/03/29 AB The dramatic air pollution episodes that occurred in the early part of the twentieth century in Belgium's Meuse Valley, Donora, Pennsylvania, and London, England, are not likely to occur in the world today. These episodes were caused by the large-scale burning of coal in the presence of “ideal” meteorologic conditions—atmospheric inversion leading to a stagnant air mass. A clearly evident excess mortality was observed during and after these episodes. Current air quality standards in North America preclude the development of episodes of this magnitude today. However, certain environmental air pollutants, such as ozone and respirable particles, do reach levels that may cause acute and chronic respiratory effects. Furthermore, in some eastern European and Asian countries, where sulfur-containing fuels are burned without adequate air quality regulations, air pollution levels may be attained similar to those that were associated with excess mortality.