Desert Dust and City Smoke: Investigating the Impact of Urbanization and Aridification on the Prevalence of Pulmonary/Pleural Inflammation in the Middle Nile Valley (2500 B.C. to 1500 A.D.).

This study investigates the impact of urbanization and aridification on prevalence rates of lower respiratory tract disease in archaeological populations from the Middle Nile Valley. Evidence for pulmonary/pleural inflammation, in the form of inflammatory periosteal reaction (IPR) on the visceral surfaces of the ribs, was recorded in human skeletal remains (452 adult/adolescent individuals, 17+ years) recovered from 12 Middle Nile Valley sites, dating from the Kerma to Medieval periods (c. 2500 B.C.-1500 A.D.). Results reveal that the urban Middle Nile Valley group presented a significantly higher prevalence rate of IPR than the rural group. Increased population density, household crowding and social mixing, poorer sanitation, and greater air, food, and water pollution may have all contributed to a high prevalence of lower respiratory tract inflammation in urban groups. To further investigate the impact of aridification and the desert environment on respiratory health, all available data from other published prevalence studies of rib IPR in adults from around the world were also collated and grouped according to Köppen climate classification. A significant difference was observed between populations from arid/semi-arid environments and populations from temperate environments. While a number of confounding factors may be involved, this result could be indicative of the impact of arid environments on respiratory health (now becoming apparent in modern clinical research). Further bioarchaeological studies of populations from different climatic and environmental conditions would be timely, considering the current concerns with climate change, including aridification and its global impact on not just respiratory health but a wide range of conditions. [ABSTRACT FROM AUTHOR]