Biocultural perspectives on birth defects in medieval urban and rural English populations
The biocultural and epidemiological approaches have been used as investigative methods by which to assess the prevalence of birth defects of the axial skeleton among five English Medieval population samples (Raunds Fumells, Northamptonshire; the hospital/almshouse of St James and St Mary Magdalene, Chichester, West Sussex; St Helen-on-the-Walls, York; Wharram Percy, East Yorkshire, and the Augustinian Friary cemetery, Hull, Humberside).The author hypothesises that Medieval urban populations produced offspring with higher frequencies of skeletal defects because they were subject to the adverse health-mediating effects of higher population density. These include poor quality, frequently overcrowded living conditions, poor sanitation, increased rates of disease threat and transmission, poorer quality food and drink due to pollution and adulteration, and greater levels of industrial-related air and water pollution. The author proposes that this response was a consequence of the impaired interaction between a population-wide compromised nutritional status and a co-existing weakened immune response. It is proposed that rural populations will express significantly lower frequencies of the same skeletal defects, as they are not subject to the same adverse environmental effects of population density and urban living conditions. The results support this hypothesis among the four populations derived from burial grounds associated with residential areas, whilst the Hull population expresses a rural pattern of defect prevalence, raising questions of possibly limited, exclusive access to burial at that site, available to non-urban dwellers. The author suggests that similar reproductive effects may be found today in populations undergoing demographic transition, for example, those experiencing the process of urbanisation in the developing world, or those migrating to the developed West. The author also shows how the results, when viewed alongside the medical literature, may indicate the presence of soft-tissue anomalies which are invisible to those working with dry bone. Keywords: urban, rural, medieval, birth defects, congenital, urbanisation, population density, biocultural, epidemiology, spine, cleft palate, skeleton, archaeology, palaeopathology.