A Longitudinal Investigation of Aggregate Oral Intake of Copper

Abstract

Four-day composite solid food and beverage duplicate plates and 1-L samples of drinking water were collected from a stratified random sample of 80 individuals as part of the National Human Exposure Assessment Survey in Maryland. The media were obtained from each participant in up to six equally spaced sampling cycles over a year and analyzed for copper by inductively coupled plasma mass spectrometry. Copper concentrations (microg/kg) and consumption rates (kg/d) of solid food, beverage and drinking water were used to derive average daily aggregate oral intake of copper (microg/d). The mean aggregate copper intake of 263 measurements obtained from 68 people was 923.2 +/- 685.6 microg/d (mean +/- SD). Intake through solid food accounted for the majority of aggregate daily intake of copper contributing 87% on average. According to results from mixed model analysis of variance procedures, the mean log-transformed average daily copper intake in each medium except beverage exhibited significant (P < 0.05) variability among sampling cycles. Between-person variability accounted for 50% of the total variance in aggregate copper intake. As measured by the coefficient of variation, distributions of copper intake consisting of one observation per individual were more variable than the distribution consisting of the long-term average intake for each person. These results suggest that estimates of the fraction of a population at risk from chronic copper deficiency or excess copper intake can be overestimated if based upon short-term measures of copper intake. In addition, these results indicate that longitudinal information is required for accurate assessment of aggregate oral intake of copper for an individual.

Determinants of temporal variability in NHEXAS-Maryland environmental concentrations, exposures, and biomarkers

“…Previous analyses of the NHEXAS-MD data have reported significant temporal variability in dietary exposures to metals and pesticides (Scanlon et al, 1999;Ryan et al, 2000;MacIntosh et al, 2001b;Pang et al, 2001;Ryan et al, 2001) and in biomarkers of pesticide exposure (MacIntosh et al, 1999b(MacIntosh et al, , 2001a, but the factors responsible for this variability have not yet been thoroughly investigated. Variability in some activities deemed relevant to pesticide exposure has been reported (Echols et al, 2001), but the association between the exposures and the activities was not investigated.…”

Deficiency, intake and the dietary requirement for copper

“…The patient, who lives in Venice, follows a Mediterranean diet. In view of the recent study by Turconi et al [3], we cannot exclude that the patient may ingest a quantity of copper below that of the daily requirement for an adult, as suggested by Klevay. However, a lack of selective absorption or the involvement of the mechanisms of transport, distribution and excretion of copper should be considered.…”

Atomic spectrometry update. Clinical and biological materials, foods and beverages

“…129 Rice was seen to be the major source of the Cd. Dietary intakes of Cu by the same individuals showed considerable variation when measured on six different occasions throughout one year 323 and it was suggested that short term investigations will give very misleading data. Intakes in infants and children also featured with analyses of breast milk and infant formulas 164,306 and total diets.…”