Lead, copper and zinc in deciduous teeth and the diet of schoolchildren in Kamloops and Trail, B.C.
Creators: name: Onishi, Geraldine Mineko
Publisher: name: University of British Columbia
Year: 2010

description: The accumulation of metal contaminants in the human environment has received a great deal of attention during the last several years as it has become apparent that their presence, in excess, represents a threat to human health. Biochemical assays to determine concentrations of metals in the human body have used such tissues as blood, bone, hair, nails and, more recently, teeth. The present study attempts to provide further evidence for the use of deciduous teeth as indicators of human exposure to concentrations of lead, copper and zinc as a result of ore smelting operations in Kamloops and Trail, British Columbia. Kamloops represents an area of minimum exposure to smelter operations in contrast to Trail where a lead/zinc smelter has been operating for many years. Concentrations of lead, copper and zinc in deciduous teeth from geographically-stable Kamloops children, aged 5 years to 12 years, were compared to concentrations found in a similar population of geographically-stable Trail children. Whole teeth were digested in nitric and perchloric acids and trace element concentrations were determined using inductively coupled plasma emission spectroscopy. Mean lead and zinc concentrations for Kamloops and Trail teeth, respectively, were: 31.6 ± 7.33 ppm and 48.2. ± 11.5 ppm for lead (p &lt; 0.05) and 103.4 ± 23.6 ppm and 111.9 ± 15.4 ppm for zinc. Copper was undetectable at &lt; 1 ppm in all teeth. Locally-grown foods from each area and foods grown elsewhere were also analyzed for lead, copper and zinc in an effort to establish the possible contribution of these elements from local food resources in Kamloops and Trail. Twenty-four hour diet composites were collected and analyzed for copper and zinc by atomic absorption spectroscopy. Mean copper and zinc concentrations for foods grown in Kamloops and Trail, respectively, were: 1.5 ± 0.4 ppm and 1.6 ± 0.9 ppm for copper and 3. 2 ± 1.3 ppm and 3.1 ± 0.9 ppm for zinc. Mean copper and zinc concentrations for non-locally grown foods collected from Kamloops and Trail, respectively, were: 1.1 ± 0.2 ppm and 1.6 ± 0.8 ppm for copper and 5.8 ± 1.9 ppm and 6.5 ± 0.3 ppm for zinc. Lead was determined by plasma emission spectroscopy, and was found to be undetectable at &lt; 1 ppm in all food samples. To assess the extent of maximal consumption of locally-grown foods, selected home gardeners in the Brocklehurst district of Kamloops and the Genelle district of Trail were interviewed. Seasonal consumption and home food preservation practices were determined. In addition, 24-hour diet recalls were obtained from 177 Brocklehurst district children in September and April, 1977-78 to determine "typical" eating patterns of these children. . The amount of locally-grown foods consumed was dependent mainly on season of the year; however, choice of food by the children on the whole did not differ from fall to spring. The recalls also indicated that males consumed more food than females, particularly protein. Meals, especially breakfast, were frequently missed, and non-nutritious snacks were common to the diets of many of the children. Results from this study indicated that, although deciduous tooth lead concentrations were significantly (p&lt;0.05) higher in Trail than in Kamloops, samples of locally-grown foods obtained in 1978 from these two communities were not excessively high in lead, zinc or copper. In fact, these elements in foods compared well to concentrations reported in other areas of North America. It would appear, then, that the higher concentrations of lead in Trail teeth are a result of increased intake from other environmental sources. Analyses of food consumption patterns of gardening families revealed that local foods comprised an important part of the diet. Measures should be taken to ensure the continued safety of foods in areas where mineral mining and smelting occur.