Through the efforts of Correa, Cuello, Haenszel, Tannenbaum and others it was learned that the incidence of gastric cancer in certain areas of Narino (Colombia) was among the highest in the world. These areas of high risk for gastric cancer were adjacent to an area of substantially lower risk. Gastric biopsies from healthy volunteers residing in the "high risk" area exhibited a greater incidence of superficial gastritis and chronic atrophic gastritis with and without intestinal metaplasia than those from the low risk area. The latter pathological finding is considered to be a precursor lesion to gastric cancer. Volunteers from the "low risk" area as well as individuals from Cali in the coastal region and Cartegena on the coast, also exhibited a similar spectrum of pathology but at a substantially reduced frequency. Natives of both cities were also at lower risk for gastric cancer than inhabitants of Narino. It was found that the water supply of the "high risk" area contained a higher concentration of nitrate than water in the "low risk" area. Correa et al. hypothesized that the high nitrate concentrations of well water contributed to the formation of N-nitroso compounds in the stomachs of these individuals early in life. The occurrence of this putative carcinogen in combination with the abrasive action of dietary grains contributed to a series of mutations in the gastric epithelium progressing through a sequence of pathologic changes, loss of gastric acid and culminating in gastric cancer. In the current report individuals in a Medellin population who were admitted with abdominal complaints and were found to be iron deficient exhibited the same spectrum of gastric pathology described by previous investigators. Superficial gastritis, chronic atrophic gastritis and achlorhydria have also been described in association with chronic iron deficiency (and/or associated nutritional defects) per se. The development of these lesions are likely to occur within the first two decades of life when iron requirements are maximal. It is suggested that these changes preceed the development of gastric cancer. Bacterial colonization of the achlorhydric stomach may facilitate nitrate reduction and the formation of a putative carcinogen N-nitroso compound(s) from nitrate in the water supply. Additionally, the effects of chronic iron deficiency on host immune defense may compromise these mechanisms and permit tumor growth with minimal immune intervention.

Marked differences in the prevalence of dental caries have been observed in two isolated villages in Colombia, South America. These differences approximate those observed between areas of minimal and optimal fluoride ingestion, although each village has less than 0.1 ppm fluoride in the drinking water. Dietary histories reveal remarkedly similar dietary practices. Samples of drinking water were collected from these villages, and analyzed by emission spectroscopy for the concentrations of 21 trace elements. In the case of 13 elements, concentrations were at or below the threshold of detection or showed minimal variability. Concentrations of calcium, magnesium, molybdenum and vanadium were higher in the water samples from the village with the low caries prevalence, while concentrations of copper, iron and manganese were higher in the samples from the village with the higher prevalence. These differences were highly significant. The caries prevalence in the high caries village was typical of the country as a whole.

Dr. Rothman and his group present a finding in two nearby villages of Colombia that no factor could explain a markedly low DMFS in the village of Heliconia.

Immunoglobulins, IgA, IgG, and IgM were found to be high in both children and adults upon admission and, though these values were within normal ranges, children were usually stabilized at a lower normal level by the time of their discharge. Adults, on the other hand, maintained high immunoglobulin levels throughout their stay, showing no significant difference between admission and discharge and experiencing few infections during hospitalization.

Notable differences in the prevalence of dental caries have been demonstrated between the children of the town of Heliconia, Colombia, and the nearby town of Don Matias (R. MEJIA, F. ESPINAL, H. VELEZ, and A. VELEZ, Bol Of Sanit Panam 66:50 1-507, 1969). The mean number of decayed, missing, and filled permanent teeth per child was 5.5 in Heliconia, and 13.9 in Don Matias; the latter figure is typical of this region of South America. Gross dietary factors and other factors known to influence dental caries, including fluoride ion consumption, do not account for the lower rate of caries in Heliconia (K. J. ROTHMAN, R. L. GLASS, F. ESPINAL, and H. VELEZ, J Public Health Dent, in press). Since it has often been hypothesized that trace metals in soil influence dental caries, presumably by a dietary effect, we examined samples of soil in Heliconia and Don Matias to determine whether the level of various trace metals in soil is associated with the caries dif-