Long-Term Associations of Morbidity with Air Pollution: A Catalogue and Synthesis
Creators: name: Lipfert, Frederick W.
Publisher: name: Taylor & Francis
Year: 2017
Subjects: subject: Space Science
subject: Medicine
subject: Physiology
subject: FOS: Biological sciences
subject: FOS: Biological sciences
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: FOS: Chemical sciences
subject: Science Policy

description: I searched the NIH Medline database through January 2017 for long-term studies of morbidity and air pollution and cataloged them with respect to cardiovascular, respiratory, cancer, diabetes, hospitalization, neurological, and pregnancy-birth endpoints. The catalogue is presented as an online appendix. Associations with PM<sub>2.5</sub>, PM<sub>10</sub>, and NO<sub>2</sub> were evaluated most frequently among the 417 ambient air quality studies identified. Associations with TSP, carbon, ozone, sulfur, vehicular traffic, radon, and indoor air quality were also reported. I evaluated each study in terms of pollutant significance (yes, no), duration of exposure, and publication date. I found statistically significant pollutant relationships (p 2.5 are most likely to be significant for cardiovascular outcomes; TSP, EC, and O<sub>3</sub> for respiratory; NO<sub>2</sub> for neurological, and PM<sub>10</sub> for birth/pregnancy outcomes. Durations of exposure range from 60 d to 35 y but I found no consistent relationships with the likelihood of statistical significance. Respiratory studies began ca.1975; studies of diabetes, cardiovascular and neurological effects increased after about 2005. I found 72 studies of occupational air pollution exposures; 40 reported statistically significant adverse health effects, especially for respiratory conditions. I conclude that the aggregate of these studies supports the existence of non-lethal physiological effects of various pollutants, more so for non-life threatening endpoints and for non-criteria pollutants (TSP, EC, PM<sub>2.5</sub> metals). However, most studies were cross-sectional analyses over limited time spans with no consideration of lag or disease latency. Further longitudinal studies are thus needed to investigate the progress of disease incidence in association with air pollution exposure. IMPLICATIONSRelationships of air pollution with excess mortality are better known than with long-term antecedent morbidity. I catalogued 489 studies of cardiovascular, respiratory, cancer, and neurological effects, diabetes, and birth outcomes with respect to 12 air pollutants. About half of the studies reported statistically significant relationships, more frequently with non-criteria than with criteria pollutants. Indoor and cumulative exposures, coarse or ultrafine particles, and organic carbon were seldom considered. Significant relationships were more likely with less-severe endpoints such as blood pressure, lung function, or respiratory symptoms, than with incidence of cancer, COPD, heart failure or diabetes. Most long-term studies are based on spatial relationships; longitudinal studies are needed to link the progression of pollution-related morbidity to mortality, especially for the cardiovascular system. Relationships of air pollution with excess mortality are better known than with long-term antecedent morbidity. I catalogued 489 studies of cardiovascular, respiratory, cancer, and neurological effects, diabetes, and birth outcomes with respect to 12 air pollutants. About half of the studies reported statistically significant relationships, more frequently with non-criteria than with criteria pollutants. Indoor and cumulative exposures, coarse or ultrafine particles, and organic carbon were seldom considered. Significant relationships were more likely with less-severe endpoints such as blood pressure, lung function, or respiratory symptoms, than with incidence of cancer, COPD, heart failure or diabetes. Most long-term studies are based on spatial relationships; longitudinal studies are needed to link the progression of pollution-related morbidity to mortality, especially for the cardiovascular system.