146 • Juan R. Munizaga 



Methods 



Our purpose was to detect the greatest number of injurious 

 effects allowed by the examination techniques applied. We 

 oriented our examination along two main lines: ( 1 ) patholog- 

 ic conditions described by other authors, considered as com- 

 mon in the pre-Columbian populations in America (Hrdlicka 

 1914; Stewart 1979:271; Weiss 1958); (2) possible effects 

 that can be caused by pressures on a sp)ecific ecosystem. In 

 our case, we think that the most aft'ected apparati and systems 

 may be the following: 



Cardiorespiratory system. Pressures upon this system are 

 exerted through the humid environment produced by the 

 coastal morning mists and the dust raised by the wind, which 

 affect the respiratory tract of children and adults (X. Vivan- 

 co, pers. comm. ). Apnea and fast decompression during div- 

 ing may cause serious health problems among fishermen of 

 the coastal area up to the present (Bittmann 1986:54). 



Locomotor}' apparatus. The physical effort made in swim- 

 ming, rowing, and diving, as well as in fishing, hunting, and 

 food collection and transport, placed the locomotory appara- 

 tus under almost perpetual stress. We will use the degenera- 

 tive changes that may have occurred in the joint surfaces 

 involved in these actions as indicators of its effect. 



Digestive system and water and salt balance. In this case, 

 pressures were made by the consumption of food with abra- 

 sive (sand) and toxic elements, such as mammal liver and 

 fish rich in vitamin A (Bamicot and Datta 1956:525), in 

 addition to the ingestion of brackish waters. The indicators of 

 their action will be wear and the loss of teeth in addition to 

 infectious disease and metabolic bone alterations. 



The presence of disease was determined through inspec- 

 tion, palpation and x-rays (Harris" lines). 



The degree of degeneration of joint surfaces was diag- 

 nosed by the presence of lipping, erosion, and ebumation. 

 The first was scored according to the degree of development 

 of osteophytes, and the last two, on the basis of the extent of 

 the destruction produced in articular surfaces (Stewart 1969; 

 Ortner 1968; Yamaguchi 1984). 



Age determination was based on fusion of epiphysial and 

 cranial vault sutures. For this purpose skulls were classified 

 in the following categories: Adult 0, vault sutures open, 

 basioccipital synchondrosis closed; Adult 1, outer suture 

 open, inner suture in the process of closing; Adult 2, outer 

 and inner sutures closing; Adult 3, outer and inner sutures in 

 advanced stage of closure. 



Results 



I classify three groups of stress according to their frequency 

 and to the knowledge we have of their causes: Group 1, a set 

 of signs corresponding to reaction patterns deriving from 

 well known environmental stimuli common to the whole 



population; Group 11, signs whose causes are known but their 

 frequency is low; Group 111, signs whose causes are unknown 

 but that appear somewhat frequently in this population. 



GROUP I 



LOCOMOTOR APPARATUS AND PHYSICAL EFFORT. The effort 



made in swimming, rowing, diving and getting food in this 

 environment forced the individuals of this population to 

 stress their joints, which led first to a plastic response, which 

 enabled them to increase their motion capacity through the 

 creation of new joint facets or the extension of the normal 

 ones. However, on occasion the stress was too strong, caus- 

 ing the progressive destruction of joint surfaces. It should be 

 noted that the highest degree of destruction is found in the 

 newly formed joint facets (excepting the front tibial facet) 

 and then the facets of the elbow and knee joints. This finding 

 is in agreement with that of other authors such as Stewart 

 (1969), Jurmain (1977,1980), and Yamaguchi (1984). My 

 findings are shown in Table 1 . 



MASTICATION APPARATUS AND FOOD. As a rCSUlt of chCwing 



hard food containing abrasive elements, a clear, reactive 

 pattern is observed which, through wear, caries and frac- 

 tures, leads to a completely edentulous status. In most cases, 

 compensating phenomena, such as secondary dentine forma- 

 tion, do not compensate for the wear. Compensating mecha- 

 nisms are also hampered by infection which, through the 

 roots, causes periapical problems leading to the destruction 

 of alveolar bone. In addition, owing to the loss of the back 

 teeth, the front teeth are subject to greater use, so that the 

 temporomandibular joint receives abnormal stress, some- 

 times giving rise to the degeneration of the joint surface. My 

 findings are shown in Table 1 . 



GROUP II 



Owing to the variety of features found in this group and to 

 their low frequency, we give some details of each case. Fre- 

 quencies are shown in Table 2. 



Harris' lines. The average number of growth arrest lines 

 observed per tibia is 1 . 1 and the percentage of affected tibiae 

 in the population is 40.0. These values are similar to those 

 found for pre-Columbian populations in the northernmost 

 Chilean coast (1.5 and 35.6% respectively), but they are 

 different from those occurring in the inland farming popula- 

 tions, which show a great frequency of these lines both at an 

 individual and at a population level: 6.2 and 67.8% respec- 

 tively (Allison et al. 1981:270). 



Hypoplastic lines of enamel. Though we established their 

 presence in several individuals, we could not determine their 

 frequency due to the high rate of postmortem loss of teeth 

 found in this population sample. 



Zagreb Paleopathology Symp. 1988 



