Respiratory disease in the Middle Nile Valley:A bioarchaeological analysis of the impact of environmental and sociocultural change from the Neolithic to Medieval periods

Abstract

Today, poor air quality is a major world-wide health burden, causing 4.2 million premature deaths per year globally, including from respiratory disease. Particulate pollution irritates and inflames the respiratory tract, increasing susceptibility to the development of respiratory conditions. Non-specific bone changes in the sinuses and on the visceral surfaces of the ribs have been linked to inflammation of the respiratory tract, caused by sinusitis and lower respiratory tract diseases. Analysis of these changes in archaeological populations is providing an historical perspective on the impact of environment, activities related to occupation, and associated socio-economic factors, such as poor ventilation in living and work spaces and low levels of hygiene, which potentially can all lead to exposure to poor air quality.

This study investigates the prevalence of abnormal bony changes to the sinuses and ribs in human skeletons from twelve Sudanese sites, ranging from the Neolithic to the Medieval periods (5000 BC – AD 1500), with a particular focus on the Fourth Nile Cataract area and comparative sites from other regions of the Nile Valley with differing sociocultural and environmental conditions. A total of 493 adults (aged 17+ years) were analysed. Changes in prevalence between sex, age, time period, and geographical region were examined. Prevalence rates of new bone formation on the visceral surfaces of the ribs displayed a general trend towards an increase in later time periods, while the frequency of bony changes associated with maxillary sinusitis remained remarkably consistent at around fifty percent in all Fourth Cataract sites. The data from the comparative sites displayed greater variation. The lowest prevalence rates for bony changes associated with respiratory disease were observed at the Neolithic site (R12) and the highest at the urban Medieval site (Soba East).

In Sudan increasing aridity from the Neolithic period until the modern day may have led to a growing exposure to environmental particulate matter from airborne dust and sand. The impact of increasing aridity, agricultural intensification, urbanisation, craft specialisation, and the emergence of visible signs of infectious diseases such as tuberculosis and leprosy, are all discussed in relation to the prevalence rates of respiratory disease between time periods and geographical regions. Changes in the environment in the Middle Nile Valley may have had a distinct effect on the presence of respiratory disease, in conjunction with exposure to other sources of particulate pollution and infectious diseases. This study of respiratory disease in Sudan provides a contextually driven perspective on a problem that is of increasing concern today across the world.