The impacts of weather and pollution on human mortality in Birmingham, Alabama and Philadelphia, Pennsylvania

• Published in: International journal of climatology 2000-06, Vol.20 (8), p.881-897
• Main Authors: Smoyer, Karen E., Kalkstein, Laurence S., Greene, J. Scott, Ye, Hengchun
• Format: Article
• Language: English
• Subjects: air pollution; Birmingham; Earth, ocean, space; Exact sciences and technology; External geophysics; human mortality; Meteorology; Other topics in atmospheric geophysics; Philadelphia; synoptic classification
• ISSN: 0899-8418; 1097-0088
• DOI: 10.1002/1097-0088(20000630)20:8<881::AID-JOC507>3.0.CO;2-V

Past studies have examined how both extreme weather and atmospheric pollutants influence human mortality. However, the differential and/or synergistic impacts of weather and pollution on mortality are poorly understood. This relationship is particularly notable in summer, when both extreme weather and high pollution episodes are frequent. The goal of this study is to describe the relationship between atmospheric conditions (as characterized by weather and air pollution) and mortality in the summer season for Birmingham, Alabama and Philadelphia, Pennsylvania. To assess the health impacts of both weather and pollution (ozone and total suspended particulates, or TSP), we used a synoptic, or air mass‐based, approach to take into account the entire weather situation, rather than individual weather elements. This method was used to identify ‘offensive’ air masses, which are associated with elevated mortality, and then to investigate which individual or combination of atmospheric conditions poses the greatest threat to human health in terms of acute (daily) mortality. In both cities, offensive weather events have a greater impact on acute mortality than high concentrations of TSP or ozone. The highest mortality levels occur when the hottest, but not the most polluted, air mass is present in each city. In Philadelphia, neither TSP nor ozone appear to contribute an ‘add on’ effect to weather‐related mortality. Under non‐offensive weather situations, pollution concentrations are associated with increased mortality in Philadelphia. Yet, regardless of pollution concentration, mortality levels are much lower for these air masses than for offensive events. Pollution appears to be more important for mortality in Birmingham. Although Birmingham's high‐mortality (offensive) air mass is not the most polluted, offensive air mass days with high pollution concentrations nonetheless exhibit higher mean mortality than offensive air mass days with low pollution concentrations. Also different from Philadelphia is a lack of a relationship in Birmingham between pollution levels and mortality on non‐offensive air mass days. The relationship between summer weather and mortality is strong in both cities, while the role of pollution is less clear. This research underscores the imperative need for the development of a weather/health watch‐warning system to alert the public that an offensive synoptic situation is imminent. Copyright © 2000 Royal Meteorological Society